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  • Rat  (190)
  • Angiosperms  (132)
  • Evolution
  • Inversion
  • evolution
  • Springer  (417)
  • 3
  • Wiley
  • 2015-2019  (1)
  • 1980-1984  (417)
  • 1
    Publikationsdatum: 2024-01-12
    Beschreibung: We present a phylogenetic analysis of spiders using a dataset of 932 spider species, representing 115 families (only the family Synaphridae is unrepresented), 700 known genera, and additional representatives of 26 unidentified or undescribed genera. Eleven genera of the orders Amblypygi, Palpigradi, Schizomida and Uropygi are included as outgroups. The dataset includes six markers from the mitochondrial (12S, 16S, COI) and nuclear (histone H3, 18S, 28S) genomes, and was analysed by multiple methods, including constrained analyses using a highly supported backbone tree from transcriptomic data. We recover most of the higher-level structure of the spider tree with good support, including Mesothelae, Opisthothelae, Mygalomorphae and Araneomorphae. Several of our analyses recover Hypochilidae and Filistatidae as sister groups, as suggested by previous transcriptomic analyses. The Synspermiata are robustly supported, and the families Trogloraptoridae and Caponiidae are found as sister to the Dysderoidea. Our results support the Lost Tracheae clade, including Pholcidae, Tetrablemmidae, Diguetidae, Plectreuridae and the family Pacullidae (restored status) separate from Tetrablemmidae. The Scytodoidea include Ochyroceratidae along with Sicariidae, Scytodidae, Drymusidae and Periegopidae; our results are inconclusive about the separation of these last two families. We did not recover monophyletic Austrochiloidea and Leptonetidae, but our data suggest that both groups are more closely related to the Cylindrical Gland Spigot clade rather than to Synspermiata. Palpimanoidea is not recovered by our analyses, but also not strongly contradicted. We find support for Entelegynae and Oecobioidea (Oecobiidae plus Hersiliidae), and ambiguous placement of cribellate orb-weavers, compatible with their non-monophyly. Nicodamoidea (Nicodamidae plus Megadictynidae) and Araneoidea composition and relationships are consistent with recent analyses. We did not obtain resolution for the titanoecoids (Titanoecidae and Phyxelididae), but the Retrolateral Tibial Apophysis clade is well supported. Penestomidae, and probably Homalonychidae, are part of Zodarioidea, although the latter family was set apart by recent transcriptomic analyses. Our data support a large group that we call the marronoid clade (including the families Amaurobiidae, Desidae, Dictynidae, Hahniidae, Stiphidiidae, Agelenidae and Toxopidae). The circumscription of most marronoid families is redefined here. Amaurobiidae include the Amaurobiinae and provisionally Macrobuninae. We transfer Malenellinae (Malenella, from Anyphaenidae), Chummidae (Chumma) (new syn.) and Tasmarubriinae (Tasmarubrius, Tasmabrochus and Teeatta, from Amphinectidae) to Macrobuninae. Cybaeidae are redefined to include Calymmaria, Cryphoeca, Ethobuella and Willisius (transferred from Hahniidae), and Blabomma and Yorima (transferred from Dictynidae). Cycloctenidae are redefined to include Orepukia (transferred from Agelenidae) and Pakeha and Paravoca (transferred from Amaurobiidae). Desidae are redefined to include five subfamilies: Amphinectinae, with Amphinecta, Mamoea, Maniho, Paramamoea and Rangitata (transferred from Amphinectidae); Ischaleinae, with Bakala and Manjala (transferred from Amaurobiidae) and Ischalea (transferred from Stiphidiidae); Metaltellinae, with Austmusia, Buyina, Calacadia, Cunnawarra, Jalkaraburra, Keera, Magua, Metaltella, Penaoola and Quemusia; Porteriinae (new rank), with Baiami, Cambridgea, Corasoides and Nanocambridgea (transferred from Stiphidiidae); and Desinae, with Desis, and provisionally Poaka (transferred from Amaurobiidae) and Barahna (transferred from Stiphidiidae). Argyroneta is transferred from Cybaeidae to Dictynidae. Cicurina is transferred from Dictynidae to Hahniidae. The genera Neoramia (from Agelenidae) and Aorangia, Marplesia and Neolana (from Amphinectidae) are transferred to Stiphidiidae. The family Toxopidae (restored status) includes two subfamilies: Myroinae, with Gasparia, Gohia, Hulua, Neomyro, Myro, Ommatauxesis and Otagoa (transferred from Desidae); and Toxopinae, with Midgee and Jamara, formerly Midgeeinae, new syn. (transferred from Amaurobiidae) and Hapona, Laestrygones, Lamina, Toxops and Toxopsoides (transferred from Desidae). We obtain a monophyletic Oval Calamistrum clade and Dionycha; Sparassidae, however, are not dionychans, but probably the sister group of those two clades. The composition of the Oval Calamistrum clade is confirmed (including Zoropsidae, Udubidae, Ctenidae, Oxyopidae, Senoculidae, Pisauridae, Trechaleidae, Lycosidae, Psechridae and Thomisidae), affirming previous findings on the uncertain relationships of the \xe2\x80\x9cctenids\xe2\x80\x9d Ancylometes and Cupiennius, although a core group of Ctenidae are well supported. Our data were ambiguous as to the monophyly of Oxyopidae. In Dionycha, we found a first split of core Prodidomidae, excluding the Australian Molycriinae, which fall distantly from core prodidomids, among gnaphosoids. The rest of the dionychans form two main groups, Dionycha part A and part B. The former includes much of the Oblique Median Tapetum clade (Trochanteriidae, Gnaphosidae, Gallieniellidae, Phrurolithidae, Trachelidae, Gnaphosidae, Ammoxenidae, Lamponidae and the Molycriinae), and also Anyphaenidae and Clubionidae. Orthobula is transferred from Phrurolithidae to Trachelidae. Our data did not allow for complete resolution for the gnaphosoid families. Dionycha part B includes the families Salticidae, Eutichuridae, Miturgidae, Philodromidae, Viridasiidae, Selenopidae, Corinnidae and Xenoctenidae (new fam., including Xenoctenus, Paravulsor and Odo, transferred from Miturgidae, as well as Incasoctenus from Ctenidae). We confirm the inclusion of Zora (formerly Zoridae) within Miturgidae.
    Schlagwort(e): Ecology ; Evolution ; Behavior and Systematics
    Repository-Name: National Museum of Natural History, Netherlands
    Materialart: info:eu-repo/semantics/article
    Format: application/pdf
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  • 2
    facet.materialart.
    Unbekannt
    Springer
    In:  Berlin, Springer, vol. 6, no. 1, pp. 1-40, (ISBN: 0-444-51340-X)
    Publikationsdatum: 1984
    Schlagwort(e): Textbook of mathematics ; lineare ; Algebra ; Inversion ; Eigen-value ; MINV ; Zurmuhl
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Acta biotheoretica 33 (1984), S. 35-50 
    ISSN: 1572-8358
    Schlagwort(e): Evolution ; falsification ; Darwinism ; philosophy of science
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In this paper we discuss the epistemological positions of evolution theories. A sharp distinction is made between the theory that species evolved from common ancestors along specified lines of descent (here called “the theory of common descent”), and the theories intended as causal explanations of evolution (e.g. Lamarck's and Darwin's theory). The theory of common descent permits a large number of predictions of new results that would be improbable without evolution. For instance, (a) phylogenetic trees have been validated now; (b) the observed order in fossils of new species discovered since Darwin's time could be predicted from the theory of common descent; (c) owing to the theory of common descent, the degrees of similarity and difference in newly discovered properties of more or less related species could be predicted. Such observations can be regarded as attempts to falsify the theory of common descent. We conclude that the theory of common descent is an easily-falsifiable & often-tested & still-not-falsified theory, which is the strongest predicate a theory in an empirical science can obtain. Theories intended as causal explanations of evolution can be falsified essentially, and Lamarck's theory has been falsified actually. Several elements of Darwin's theory have been modified or falsified: new versions of a theory of evolution by natural selection are now the leading scientific theories on evolution. We have argued that the theory of common descent and Darwinism are ordinary, falsifiable scientific theories.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 40 (1984), S. 1004-1006 
    ISSN: 1420-9071
    Schlagwort(e): Rat ; adrenocortical responsiveness ; ACTH ; plasma ; corticosterone ; plasma ; corticotropin releasing factor (CRF)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the course of studying the plasma adrenocorticotropic hormone (ACTH) and corticosterone responses to synthetic corticotropin releasing factor (CRF), we noted some disparity in the responses. A higher dose (20 μg compared with 5 μg per rat i.a.) produced an equal plasma ACTH but greater plasma corticosterone response in adult male rats. Thus, we examined the possibility that CRF increases adrenocortical responsiveness to ACTH. CRF significantly (p〈0.0005) increased the plasma corticosterone response to ACTH in rats pretreated with dexamethasone. Thus, synthetic CRF increases corticosterone secretion in rats not only by stimulating ACTH secretion, but also by increasing the adrenocortical responsiveness to ACTH.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 40 (1984), S. 974-975 
    ISSN: 1420-9071
    Schlagwort(e): Rat ; prostaglandins ; gastric lesion ; intragastric distension model ; stress model ; indomethacin ; somatostatin preventive effect
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The inhibition of endogenous prostaglandin synthesis by indomethacin treatment blocks the somatostatin preventive effect on the gastric lesions induced in a stress model and has no preventive effect on an intragastric distension model.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular evolution 21 (1984), S. 54-57 
    ISSN: 1432-1432
    Schlagwort(e): Mitochondrion ; Cytochrome C ; Rhodospirillaceae ; Endosymbiosis ; rRNA ; Evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The comparative morphology and pigmentation of protists suggest that those with tubular mitochondrial cristae belong to a different lineage than those with lamellar cristae and that the evolutionary divergence might have been very early. We propose that the difference in cristal morphology is the result of separate origins of the mitochondria from endosymbionts related to the Rhodospirillaceae (purple nonsulfur bacteria) but differing in the morphology of their internal membranes. Comparisons of the cytochromes c of protists and the Rhodospirillaceae and of 16s rRNA T1 oligonucleotide catalogs in the Rhodospirillaceae do not contradict, and in fact provide support for, the idea. More extensive evidence may be lacking simply because cytochromes c have been studied in very few protists with tubular mitochondrial cristae.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular evolution 21 (1984), S. 72-75 
    ISSN: 1432-1432
    Schlagwort(e): Heat ; Rates of copy error ; Evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Heat induces a number of premutational lesions (for example, the deamination of cytosine to uracil) in DNA and RNA. These kinds of errors occur in resting as well as replicating polynucleotides. However, an increase in temperature also raises the probability of copying error occurring in nucleic acids because of increased thermal noise in the replicative machinery. In most modern genetic systems, the majority of heat-induced lesions are efficiently repaired. It follows that the importance of heat-induced error increases as the effectiveness of repair declines. We show in this paper that the error rate of enzymatic polynucleotide copying is expected to increase monotonically with temperature. We also explore the effects of temperature variations on the early evolution of biological information transmission mechanisms.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular evolution 20 (1984), S. 128-134 
    ISSN: 1432-1432
    Schlagwort(e): Snake venom ; Neurotoxin ; Cytotoxin ; Evolution ; Circular dichroism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The amino acid sequences of the 139 homologous “short” neurotoxins, “long” neurotoxins and cytotoxins so far characterised from elapid snake venoms were compared on the basis of the amino acid deletion/insertion events that have occurred during evolution. Systematic grouping of the toxins according to similarity suggests that the short neurotoxins resemble the cytotoxins more closely than they do the long neurotoxins. The significance of this finding is discussed in relation to the methodology, the conformations of the toxins (as represented by circular dichroism spectra) and the outcome of the study that would have been obtained had more traditional methods been used. It appears probable that the cytotoxins evolved relatively recently from neurotoxic ancestors.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-1432
    Schlagwort(e): Balbiani ring ; Repeat ; Evolution ; Repetitive DNA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary All known types of Balbiani ring (BR) gene consist of multiple, tandemly arranged, ca. 180 to 300-bp repeat units that can be divided into a constant region and a subrepeat region. The latter region includes short tandem subrepeats (SRs). Comparison of all available BR sequences using computer methods has enabled us (a) to define more precisely the constant and subrepeat regions, (b) to infer the evolutionary relationships among the various types of BR repeats, (c) to derive a consensus approximation of an ancestral sequence from a small segment of which the highly diverse present-day SRs may have originated, and (d) to detect an underlying substructure in the constant region, evident in the consensus but not in the present-day sequences and possibly corresponding to an original 39-bp DNA segment from which the extant, giant BR sequences may have evolved. We discuss the processes of reduplication, diversification, and homogenization within the hierarchically repetitive BR sequences as examples of how a simple DNA element may evolve into a diverse family of large, protein-coding genes.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1432-1432
    Schlagwort(e): Evolution ; Gene family ; Balbiani ring genes ; Repetitive sequences ; Structural proteins ; Protein conformation ; Polymerization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The large, repetitive Balbiani ring (BR) genes, BR 1, 2, and 6, inChironomus tentans originated from a short ancestral sequence and have all evolved according to analogous amplification schemes. We analyzed the structures of the BR-encoded secretory proteins and defined the parts that have been conserved during the evolutionary process. The BR products show striking similarities, with the BR 1 and BR 2 products being more similar to each other than to the BR 6 product. In the constant (C) region of the repeat units, 7 of the 30 amino acid residues are strictly conserved; 4 of these are the cysteine residues. The subrepeat (SR) regions of all the BR products are dominated by repeated tripeptide elements rich in proline and charged amino acid residues. Most of the amino acid replacements in both regions are conservative. Secondary structure predictions suggested that the C regions of the BR 1 and BR2 products have several elements of secondary structure: an α-helix, a β-strand, and one or two reverse turns, as in “globular structures.” The prediction for the C region of the BR 6 product is similar but lacks a β-strand. The predictions for the intervening SR regions appear less conclusive, but are clearly different from those for the C regions, and suggest regular structures not differing in their conformational elements. The SR regions evolved from an ancestor sequence similar to the C region; thus, the BR products seem to represent an example of evolution from one structure to two differently folded products. It is proposed that the alignment and polymerization of the long BR proteins could be promoted by the repetitive structure of the molecules, due to the possibility of forming disulfide bridges between half-cystine residues and electrostatic interactions between the charged residues of the SR regions. The divergence among the BR products is discussed in relation to possible functional differences among the members of the BR gene family.
    Materialart: Digitale Medien
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  • 11
    ISSN: 1420-9071
    Schlagwort(e): Rat ; cerebrospinal fluid, human ; analgesia ; naloxone ; pain indifference, congenital ; opiates, endogenous
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary CSF from a patient with congential indifference to pain was found to produce analgesia in the rat following intracerebroventricular injections. The analgesic effect was attenuated by pretreatment with naloxone suggesting the involvement of hyperactive endogenous opiate mechanisms in this patient.
    Materialart: Digitale Medien
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 40 (1984), S. 1368-1369 
    ISSN: 1420-9071
    Schlagwort(e): Rat ; kidney ; hypertensive ; prostaglandin dehydrogenase ; hexokinase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 15-Hydroxyprostaglandin dehydrogenase (PGDH) surged in hypertensive (SHR) and normotensive (WKY) rat kidney at 8 days of age, is greatest in SHR. Hexokinase fell in SHR at 17 days of age, but thereafter was similar to WKY. This suggests multisystem enzymatic abnormalities in SHR kidney during development of hypertension.
    Materialart: Digitale Medien
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 40 (1984), S. 942-944 
    ISSN: 1420-9071
    Schlagwort(e): Insect hormones ; estradiol ; estriol ; evolution ; sex hormones
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Insects representing 5 different orders contain androgen and estrogen-like substances as determined by radioimmunoassay. Estradiol and estriol have been identified by gas chromatography-mass spectrometry. The presence of these steroids in insects suggests that the vertebrate sex hormones have an ancient evolutionary history.
    Materialart: Digitale Medien
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 40 (1984), S. 1008-1010 
    ISSN: 1420-9071
    Schlagwort(e): Rat ; ethanol preference ; acetaldehyde self-administration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Peripherally self-injected acetaldehyde in interaction with environmental and nutritional variables significantly enhances alcohol drinking in rats and suggests an involvement of acetaldehyde in voluntary alcohol intake.
    Materialart: Digitale Medien
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  • 15
    ISSN: 1432-0983
    Schlagwort(e): Plastid DNA ; Cytochrome b6 gene ; Amino acid sequence ; Hydropathy ; Thylakoid membrane ; Transcript modification ; Evolution ; Spinach
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A 2.4 kilobase-pair segment of the spinach plastid chromosome carrying the genes for apocytochrome b6 and subunit 4 of the thylakoid membrane cytochrome b/f complex has been analysed by DNA sequencing and Northern blot analysis. The nucleotide sequence reveals two uninterrupted open reading frames of 211 and 139 triplets coding for two hydrophobic proteins of 23.7 kd (cytochrome b6) and 15.2 kd (subunit 4). The genes are located on the same strand and are separated from each other by 1018 untranslated base pairs. They map adjacent to the gene for the P680 chlorophyll α apoprotein of the photosystem II reaction center. The three genes appear to be under common transcriptional control and the transcripts post-transcriptionally modified. The deduced amino acid sequences of cytochrome b6 and subunit 4 both exhibit significant homology with published sequences from mitochondrial b cytochromes (42 kd) suggesting that these functionally equivalent polypeptides in photosynthetic and respiratory electron transport chains arose monophyletically.
    Materialart: Digitale Medien
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  • 16
    ISSN: 1432-072X
    Schlagwort(e): Superoxide dismutase ; Glutamine synthetase ; Evolution ; Marine bacteria ; Alcaligenes ; Alteromonas ; Deleya ; Oceanospirillum ; Pseudomonas
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Evolutionary relationships among marine species assigned to the genera Alteromonas, Oceanospirillum, Pseudomonas, and Alcaligenes were determined by an immunological study of their Fe-containing superoxide dismutases (FeSOD) and glutamine synthetases (GS), two enzymes with differentially conserved amino acid sequences which are useful for determining intermediate and distant relationships, respectively. Five reference antisera were prepared against the FeSODs from Alteromonas macleodii, A. haloplanktis, Oceanospirillum commune, Pseudomonas stanieri, and Deleya pacifica. For GS, a previously prepared antiserum to the enzyme from Escherichia coli was employed. Amino acid sequence similarities for both enzymes were determined by the quantitative microcomplement fixation technique and the Ouchterlony double diffusion procedure. Six evolutionary groups were detected by FeSOD sequence similarities: three subgroups within the genus Alteromonas, the genera Oceanospirillum and Pseudomonas, and a new genus, Deleya (to accommodate marine Alcaligenes). Only four groupings were delineated by the GS data: the latter three genera and one group composed of all the species of Alteromonas. Evidence that all of these subgroups are derived from the evolutionary lineage defined by the purple sulfur photosynthetic bacteria is presented.
    Materialart: Digitale Medien
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Journal of mathematical biology 19 (1984), S. 329-334 
    ISSN: 1432-1416
    Schlagwort(e): Evolution ; ESS ; games ; game dynamics ; n-person games ; strategies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Mathematik
    Notizen: Abstract This note contains a generalization of the definition of an evolutionary stable strategy and of the corresponding game dynamics from 2-person to n-person games. This broader framework also allows modelling of several interacting populations or of populations containing different “types” of individuals, for example males and females.
    Materialart: Digitale Medien
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Journal of mathematical biology 21 (1984), S. 77-95 
    ISSN: 1432-1416
    Schlagwort(e): Evolution ; quantitative inheritance ; random matrix theory ; morphological integration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Mathematik
    Notizen: Abstract A quantitative genetic model of “random pleiotropy” is introduced as reference model for detecting the kind and degree of organization in quantitative genetic variation. In this model the genetic dispersion matrix takes the form of G = BB T, where B is a general, real, Gaussian random matrix. The eigenvalue density of the corresponding ensemble of random matrices (ℰG) is considered. The first two moments are derived for variance-covariance matrices G as well as for correlation matrices R, and an approximate expression of the density function is given. The eigenvalue distribution of all empirical correlation matrices deviates from that of a random pleiotropy model by a very large leading eigenvalue associated with a “size factor”. However the frequency-distribution of the remaining eigenvalues shows only minor deviations in mammalian skeletal data. A prevalence of intermediate eigenvalues in insect data may be caused by the inclusion of many functionally unrelated characters. Hence two kinds of deviations from random organization have been found: a “mammal like” and an “insect like” organization. It is concluded that functionally related characters are on the average more tightly correlated than by chance (= “mammal like” organization), while functionally unrelated characters appear to be less correlated than by random pleiotropy (“insect like” organization).
    Materialart: Digitale Medien
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  • 19
    Digitale Medien
    Digitale Medien
    Springer
    Theoretical and applied genetics 68 (1984), S. 187-192 
    ISSN: 1432-2242
    Schlagwort(e): Vicia ; nuclear DNA ; Evolution ; Base sequence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The composition of nuclear DNA in 3 Vicia species are compared. The species V. eriocarpa, V. johannis and V. melanops are from three separate subgeneric sections of Vicia and show a fourfold variation in their amounts of nuclear DNA. DNA melting experiments, buoyant density gradient analysis and Cot reassociation experiments show that the quantitiative change in nuclear DNA between the three species is achieved by changes in the amounts of both repetitive and nonrepetitive DNA sequences. It is suggested that while the increase in the repetitive fraction is achieved by the proliferation of repetitive base sequences the increase in the nonrepetitive fraction is due to the steady accretion of highly diverged base sequences resulting from mutations, deletions, insertions and base sequence rearrangements among families of repetitive sequences.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 373-381 
    ISSN: 1432-0878
    Schlagwort(e): Merkel cell surface ; Quinacrine fluorescence ; Lectins ; Vibrissae ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Surface carbohydrates on the Merkel cell of the outer root sheath (ORS) were investigated in 1to 4-day-old rat vibrissae by use of rhodamine isothiocyanate (RITC)-conjugated lectins. The red fluorescence of RITC provided a convenient assay for lectin binding to the Merkel cell, which is itself identified by its green fluorescence following selective uptake of the dye quinacrine. In monolayers or suspensions of freshly dissociated ORS cells, the Merkel cell showed high affinity for the α-fucose-specific lectin, Ulex europeus agglutinin I (UEA-I), thus revealing a novel feature for a basally located cell. Other high-affinity lectins included concanavalin A (Con A), wheat germ agglutinin (WGA), soybean agglutinin (SBA), and Ricinus communis agglutinin I (RCA-I). In contrast, Dolichos biflorus (DBA), Bandeiraea simplicifolia I and II (BS-I and BS-II), and peanut agglutinin (PNA) virtually excluded the Merkel cell, though PNA-binding sites were unmasked after neuraminidase treatment. Other dispersed ORS cells had varying lectin affinities, and generally binding was inhibited by a competing haptenic sugar. The pattern of lectin binding seen in cryostat and paraffin sections of the vibrissa suggested that the Merkel cells share surface properties with their neighboring basal and/or spinous cells; however, unshared properties are likely to exist since ingrowing mechanosensory nerves recognize the Merkel cells, and not other epidermal cells, as their targets.
    Materialart: Digitale Medien
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 711-715 
    ISSN: 1432-0878
    Schlagwort(e): Gastric antral mucosa ; Caerulein ; Gastrointestinal hormones ; Cholecystokinin ; Trophic effect ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The growth-promoting effect of caerulein on antral gastric mucosa was explored using Wistar rats. Implanted osmotic minipumps were used to administer submaximal doses of either caerulein or saline to normal rats for up to 4 days. In one group, reflux of bile and pancreatic juice into the stomach was avoided by previous surgical diversion of the distal common bile duct to the jejunum. DNA synthetic and mitotic activity in the antrum epithelium were estimated by 3H-thymidine pulse labelling and autoradiography during the administration of the peptide. The rate of cell migration was determined in animals killed 1, 2 and 3 days after the 3H-thymidine pulse. Administration of caerulein to normal rats provoked significant increases in both labelling and mitotic indices, and a significant acceleration of the upward cell migration in the glandular tubes. In the animals with distal diversion of bile and pancreatic secretions both labelling and mitotic indices were also increased over control values under the effect of the peptide. These data indicate that administration of caerulein stimulates cell proliferation in the antral gastric mucosa. This effect cannot be explained through increased reflux of pancreaticobiliary secretions in the stomach.
    Materialart: Digitale Medien
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 699-709 
    ISSN: 1432-0878
    Schlagwort(e): Testis ; Spermatogenic cycle ; Sertoli cell ; Lipid ; Morphometry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The volume and surface area of lipid inclusions often present in the cytoplasm of rat Sertoli cells was measured directly from semi-thin sections of perfusion-fixed testicular tissues using an image analyser linked to a light microscope. Sertoli cell nuclei were used as a reference for comparing any variations in the measured parameters of lipid inclusions during the rat spermatogenic cycle. Volume density of Sertoli cell lipid inclusions was assessed by morphometric analysis of Sertoli cells photographically reconstructed from electron micrographs. Maximum lipid content in Sertoli cells occurred during stages IX–XIV of the spermatogenic cycle, then declined at stages I–III and remained low from stages IV–VIII. The persistence and increase in number of many large Sertoli cell lipid inclusions beyond the stage where spermatid residual bodies are phagocytosed within the Sertoli cells (stage IX) suggests that the synthesis and lipolysis of Sertoli cell lipid inclusions represents an intrinsic functional cycle of the Sertoli cells. Stage-dependent variations in the lipid content of rat Sertoli cells offers morphological evidence that the metabolic duties of the Sertoli cells are synchronised with the spermatogenic cycle to provide local coordination of the proliferation and maturation of the germ cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 717-724 
    ISSN: 1432-0878
    Schlagwort(e): Ovary ; Ovarian follicle ; Atresia ; Immunoregulation ; Immune tolerance ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Thy-1+ cells, producing Thy-1+ material, have been demonstrated by the indirect immunoperoxidase technique in the theca of growing ovarian follicles of the rat. OX-2 antigen, known as the minor glycoprotein of rat thymocytes, was detected in granulosa cells of non-growing follicles. Ia+ cells of dendritic type and/or activated macrophages were identified in the granulosa of advanced degenerating follicles, and remnants of the zona pellucida exhibited immunoglobulins. In some ovaries immunoglobulins were also bound to the zona pellucida of oocytes of early degenerating antral follicles. Medium-sized antral follicles with degenerating granulosa were occasionally invaded by cells carrying antigens of cytotoxic T lymphocytes or other T lymphocyte subsets, while degenerating large antral follicles were sometimes invaded by cells exhibiting antigen of cells with natural killer function (but not antigens of T lymphocytes). Granulosa cells of some degenerating antral follicles exhibited class-I antigens derived from the major histocompatibility complex. We suggest that cell-mediated control mechanisms of antigen expression and metabolism of tissue cells during their differentiation and degeneration should be considered in addition to the well-documented hormonal dependence of some tissues.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 245-252 
    ISSN: 1432-0878
    Schlagwort(e): Pineal organ ; Interstitial cells ; Astrocytes ; Immunocytochemistry ; Rat ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Antigenic markers characteristic of astrocytes and their differentiative states (i.e., glial fibrillary acidic protein (GFAP), vimentin, and M1 and C1 antigens) were investigated in the pineal gland of mouse and rat using double immunolabeling techniques. In both species the socalled interstitial cells as characterized by TEM were shown to be astrocytes, since they expressed vimentin, but neither fibronectin (a marker for fibroblasts and endothelial cells) nor the neuron-specific L1 antigen or tetanus toxin receptors. Subpopulations of vimentin-positive pineal astrocytes were also GFAP- and C1- antigen-positive. M1- antigenpositive cells were not detected. It is concluded that a considerable proportion of interstitial cells in the pineal gland of rat and mouse are immature astrocytes which, in contrast to other parts of the central nervous system, persist into adulthood.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    ISSN: 1432-0878
    Schlagwort(e): Thyroid gland, fetal ; Cytoskeleton ; Cytocha lasin B ; Vinblastine ; Colchicine ; Follicular development (thyroid) ; Tissue culture ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Thyrotropic hormone (TSH) or cAMP accelerate the formation of follicular cavities in the explanted thyroid gland of the 15-day-old rat fetus. Cytochalasin B or vinblastine and nocodazole or colchicine, which disorganize microfilamental and microtubular structures respectively, inhibit or completely block in vitro-induced folliculogenesis. Exposure of the thyroid tissue to lumicolchicine, a structural isomer of colchicine deprived of antimicrotubular activity, does not inhibit the activation of folliculogenesis induced by TSH. These results are strong evidence for the supposition that microfilaments and microtubules are involved in the TSH-stimulated mechanisms resulting in thyroid folliculogenesis. Folliculogenesis requires the integrity of both microfilaments and microtubules.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 26
    ISSN: 1432-0878
    Schlagwort(e): CRF-neurons ; Hypothalamus ; Development, ontogenetic ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Appearance of immunoreactive corticotropin-releasing factor (CRF)-containing neurons was studied in developing hypothalamus of the rat by use of antisera against rat- and ovine CRF. These neurons were first recognized in the lateral and paraventricular nuclei on days 15.5 and 16.5 of gestation, respectively, when antiserum against rat CRF was employed. Antiserum against ovine CRF revealed the cells two days later exclusively in the latter nucleus. In both nuclei, the neurons increased in number with development. The neurons in the paraventricular nucleus appeared to project their immunoreactive processes to the median eminence via the periventricular and lateral pathways. In the median eminence, the immunoreaction with antiserum to rat CRF was first recognized in its anterior portion in the form of dots on day 16.5 of gestation but as beaded fibers in the external layer on day 17.5; these structures increased in amount with development in rostro-caudal direction. Although antiserum to ovine CRF was less potent in immunostainability than antiserum to rat CRF, it also revealed the beaded fibers in the median eminence on day 17.5 of gestation. Since evidence is available that the paraventricular nucleus is involved in corticotropin release, it is concluded that, in rats, the hypothalamic regulatory mechanism controlling the release of corticotropin initially appears on days 16.5–17.5 of gestation.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    ISSN: 1432-0878
    Schlagwort(e): Caldesmon ; Actin ; Immunocytochemistry ; Small intestine ; Smooth muscle ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The distribution of caldesmon (a calmodulin-binding, F-actin-interacting protein) (Sobue et al. 1982) and of actin was studied in the rat's small intestine by means of light-microscopic immunocytochemistry. Positive immunostaining for caldesmon was seen in smooth muscle cells of the intestinal wall, and of blood vessels, and in the apical portion of the absorptive epithelial cells. The immunoreactivity in goblet cells was difficult to recognize. The positive reaction to immunostaining for actin showed almost the same pattern as that for caldesmon. These results suggest that this calmodulin-binding protein may play an important role in the control of actin-myosin interaction in smooth muscle cells and in non-muscle cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 235 (1984), S. 433-438 
    ISSN: 1432-0878
    Schlagwort(e): Mammary gland ; Ferritin-concanavalin A ; Concanavalin A ; Endocytosis ; Membrane reuse ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ferritin-concanavalin A (Fer-Con A) was used to label the apical plasma membrane of the lactating cell to determine whether membrane internalization takes place. Rat glands were infused in vivo via the teat with 0.2 mg of Fer-Con A in 0.2 ml tris buffer (pH 7.0) containing 0.1% trypan blue, the latter acting as a marker of the infusate. Tissues were obtained from separate animals 5, 10 and 60 min postinfusion. Fer-Con A was seen in alveolar lumina bound to the outer surfaces of apical plasma membrane, microvilli and milk fat globules. It was observed within lactating cells on the inner membrane surfaces of endocytotic vesicles, Golgi cisternae, and secretory vesicles containing casein micelles, and in multivesicular bodies and lysosomes. Internalization of the ferritin-lectin conjugate into casein-containing secretory vesicles was detectable in the 5-min postinfusion tissue. Lysosomes were the only structures in control tissue that contained particles bearing some resemblance to Fer-Con A. The data provide evidence that apical plasma membrane is internalized and distributed to a number of intracellular compartments.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 235 (1984), S. 449-452 
    ISSN: 1432-0878
    Schlagwort(e): Suprachiasmatic nucleus ; Morphometry ; Synapses ; Sexual dimorphism ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The suprachiasmatic nucleus (SCN) of male rats was estimated to contain 16×106 synaptic appositions (unilaterally) or 250×106 appositions in 1 mm3 tissue of the nucleus with an average of 1404 appositions per neuron. There are significantly fewer synaptic appositions in the suprachiasmatic nucleus of female rats (15×106 per SCN or 236×106 in 1 mm3 tissue of SCN with 1264 appositions per neuron on an average). Additionally, numbers of various types of synapses (axo-somatic, invaginated, dendrodendritic and optic) are estimated.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    ISSN: 1432-0878
    Schlagwort(e): Monosodium-1-glutamate ; Neuropathology ; Rat ; Superior colliculus ; Toxicology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Systemic administration of monosodium-1-gluta-mate by single injections of 4 mg/g body weight in infant rats (2–10 days of age) results in acute swelling of cytoplasm and nuclear pyknosis of neurons in the stratum zonale and stratum griseum superficiale of the superior colliculus. Multiple daily doses of 4 mg/g body weight monosodium-1-glutamate result in an almost complete loss of neurons in these two superficial layers. The deeper layers appear not to be affected. No pathological effects were observed in the lateral geniculate body or pretectal complex. Light-and electron-microscopic studies reveal that the optic nerves are remarkably shrunken and many myelinated as well as unmyelinated axons are lost. Injection of 3Hproline into the vitreous body of one eye results in limited transport to the suprachiasmatic nucleus, lateral geniculate body and to lateral portions of the superior colliculus. The small percentage of intact axons in the optic nerve, as well as the limited proline transport from the eye, suggest that administration of monosodium-1-glutamate leaves intact some optic fibers, a portion of which belongs to the retinohypothalamic tract.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    ISSN: 1432-0878
    Schlagwort(e): Exocrine pancreas ; Calcium pool ; Calcium release ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In an attempt to identify a cellular Ca2+-pool, from which calcium is released when secretagogues are applied, tissue fragments of the rat exocrine pancreas were incubated and fixed with glutaraldehyde in the presence of calcium. By means of this procedure electron-dense deposits were found on plasma membranes. X-ray microanalysis showed that these deposits contain calcium. Stimulation of tissue fragments with the use of the secretagogues carbachol or cholecystokinin reduced the number of deposits by about 80%. When the antagonist atropine was applied after carbachol stimulation, deposits reappeared on cell membranes, which then disappeared again after a second stimulation with cholecystokinin. In the presence of procaine, carbachol was inhibited and only slightly reduced the Ca2+-deposits on the plasma membranes. These results suggest that a calcium pool, from which calcium is released to induce enzyme secretion on stimulation, is located in the cell membrane
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 32
    ISSN: 1432-0878
    Schlagwort(e): Somatostatin ; Ontogenesis ; Electron-microscopic immunohistochemistry ; Median eminence ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The development of immunoreactive (ir) somatostatin-containing nerve terminals in the rat median eminence (ME) has been examined electron-microscopically. Nerve fibers containing ir particles scattered throughout the axoplasm are first seen in the external layer of the ME on day 18.5 of gestation, and, on day 21.5 appear to terminate on the basement membrane of the perivascular space of the portal vessels. After birth, the fiber terminals contain several membrane-limited granules, which are labeled with ir PAP particles. Ultrathin, Epon-embedded sections of ME, treated by the protein A gold-labeling method for somatostatin, demonstrate positively labeled granules in the nerve fibers in the postnatal ME, but in the prenatal tissue, no specific gold-labeling is found. These findings show that, in the external layer of the ME, somatostatin storing occurs in the granules in the axonal terminals after birth.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 491-493 
    ISSN: 1432-0878
    Schlagwort(e): Brain vessels ; Basal lamina ; Pericytes ; Endothelial cells ; Glial cells ; Argyrophilic staining ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Vibratome sections obtained from perfusion-fixed rat brains were stained by means of silver impregnation and physical development according to Gailyas (1970). Small pieces of the cerebral cortex were postfixed with buffered osmium tetroxide solution and processed for electron microscopy to examine the localization of the silver deposit at the cellular level. The cell surfaces of pericytes and smooth muscle cells were completely outlined by silver grains. Endothelial cells and perivascular astrocytes, however, showed an asymmetric distribution of the silver deposit, i.e., the deposit was restricted to the abluminal endothelial surface and to the astrocytic membrane adjacent to the vessel wall, respectively. The method allowed a clear-cut distinction between perikarya of endothelial cells and pericytes as well as glial cells in perivascular position, even at the light-microscopic level.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 34
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 249-255 
    ISSN: 1432-0878
    Schlagwort(e): Oocyte ; Nucleolus ; Silver staining ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The nucleoli of dictyate-stage growing oocytes in rat ovaries were examined both with routine electron microscopy and electron microscopy after silver nitrate and ammoniacal silver nitrate (Ag-AS) staining. The nucleoli of the unilaminar follicular oocytes consist of twisted strands of dense fibrillar components, aggregates of granular components, and small fibrillar centers. After Ag-AS staining, silver grains are numerous on the dense fibrillar strands, fewer on the fibrillar centers, and very sporadic on the granular aggregates. The same stainability of three nucleolar components with the Ag-AS method was also confirmed in the nucleoli segregated by actinomycin D. During the transition of growing oocytes from bilaminar to plurilaminar follicle stage, the nucleolar dense fibrillar strands gradually conglomerate and are transformed into large and compact spherules. The stainability of dense fibrillar components with the Ag-AS method was lost along with this nucleolar transformation. These results may provide some new clues on the functional significance of AgAS-positive proteins in the nucleoli.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 103-109 
    ISSN: 1432-0878
    Schlagwort(e): Synapses ; Synaptogenesis ; Development fetal ; Olfactory cortex ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Electron microscopy was used to study synaptogenesis in prepyriform cortex of fetal rat pups during early stages of synapse formation. Of special interest is the frequent occurrence of unapposed, developing synaptic specializations in axon and growth cone profiles. The location and morphology of the unapposed specializations suggests that thay are presynaptic in nature. These presumably immature presynaptic specializations are found in the lateral olfactory tract and subjacent cortex. Intermediate forms between uncontacted presynaptic specializations and definitive synapses suggest a synaptogenic sequence in which initial development of an immature presynaptic specialization begins without apposition of a postsynaptic element at that location. This implies that initiation of presynaptic development is not dependent upon postsynaptic contact and also raises the question of whether synaptic contacts could be established via presynaptic induction of postsynaptic formation.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 185-186 
    ISSN: 1432-0878
    Schlagwort(e): Gap junction ; Cytoskeleton ; Heart ; Ultrarapid freezing ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Using ultrarapid-freezing techniques and freezefracture electron microscopy, we report here a close association between cardiac gap junctions and specialized membrane domains containing regularly-spaced furrows. These specialized furrowed domains are observed only during periods of gap junction re-organisation (i.e., connexon redistribution) and may reflect the presence of underlying cytoskeletal elements controlling the position of connexons in the membrane.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 371-373 
    ISSN: 1432-0878
    Schlagwort(e): Endothelium ; Transport, intracellular ; Transport vesicles, channels ; Micropinocytosis ; Capillaries ; Endometrium ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Three types of transendothelial channels are described in the endothelium of blood capillaries in the endometrium of the rat. It is postulated that they may function as pores draining interstitial fluid to the venous blood.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 375-377 
    ISSN: 1432-0878
    Schlagwort(e): Thyroid ; Immunocytochemistry ; Caldesmon ; Actin ; Endocytosis ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The distribution of caldesmon (a calmodulin-binding, F-actin interacting protein; Sobue et al. 1982) and actin was studied in the rat thyroid gland by means of light-microscopic immunocytochemistry, and the fine-structural distribution of actin filaments was examined by use of heavy meromyosin (HMM). Caldesmon and actin were demonstrated in the apical cytoplasm of almost all the follicle epithelial cells in normal as well as TSH-treated animals. Immunoreactivities for both caldesmon and actin showed almost the same pattern in localization. The smooth muscle cells of the blood vessels were also positive for caldesmon and actin. By electron microscopy, numerous actin filaments decorated by HMM and running perpendicularly or randomly to the apical surface were recognized in the apical cytoplasm of the follicle epithelial cell. These results suggest that caldesmon and actin, in conjugation with calmodulin, play a role in the regulation of cellular activity such as exocytosis and endocytosis in the apical portion of the follicle epithelial cell.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 235 (1984), S. 187-194 
    ISSN: 1432-0878
    Schlagwort(e): Golgi apparatus ; Monensin ; Small intestine ; Cytochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effect of short-time treatment with the ionophore monensin, administered intraluminally at concentrations of 5 and 10 μM, was studied on the Golgi apparatus of absorptive cells in the small intestine of the rat. At 2–3 min after treatment most of the Golgi stacks exhibited dilated cisternae. At 4–5 min stacked cisternae were absent; they were replaced by groups of smooth-surfaced vacuoles. Dilatation and vacuolization occurred in the entire stacks without preferential effect on any particular Golgi subcompartment. Monensin did not influence the cytochemical Golgi reaction of thiamine pyrophosphatase and acid phosphatase. The characteristic staining pattern of these two enzymes in all Golgi cisternae of absorptive cells in the proximal small intestine, and the reactivity restricted to trans cisternae in distal segments of the small intestine, were unchanged after treatment with monensin. In the distal small intestine, the cytochemical pattern allowed the monensin-induced vacuoles to be attributed to the former cisor trans-Golgi face. Further, the cytochemical results demonstrate that vacuolization is not restricted to the stacked cisternae, but includes the trans-most cisterna. The latter, usually located at some distance from the Golgi stacks, has been defined as belonging to the GERL system in several types of cells. The clear response to monensin, an agent that selectively affects the Golgi apparatus, indicates common properties between trans-most and stacked Golgi cisternae.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 235 (1984), S. 485-489 
    ISSN: 1432-0878
    Schlagwort(e): Ventromedial nucleus ; Hypothalamus ; Ultra-structure ; Nucleoli ; Estrogen effects ; Chromatin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Estrogen is accumulated from the blood by nerve cells in the ventromedial nucleus of the hypothalamus and can facilitate female reproductive behavior by acting on this region of the brain. This cell group was examined in ovariectomized female rats, given estrogen or control treatment, by use of light and electron microscopy. A significantly greater portion of the nerve cells in the estrogen-treated animals had protuberances on their nucleolar surfaces, apparent under the light microscope. The fine structure of such protuberances included dense, aggregated material, which is shown to contain DNA by the sodium tungstate staining technique. Because increased numbers of such protuberances were found in nuclei of cells of the experimental group where previous studies demonstrated a significant increase in ultrastructural signs of biosynthetic activity, they may be associated with increased RNA synthesis. Thus, they could indicate, ultrastructurally, increased synthetic rates for RNA in nerve cells through which estrogen promotes reproductive behavior.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 41
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 235 (1984), S. 657-661 
    ISSN: 1432-0878
    Schlagwort(e): Evolution ; Endocrine pancreas ; Regulatory peptides ; Snakes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The pancreas from eleven species of snakes representing both advanced and primitive families has been investigated for the presence of eleven regulatory peptides reported to occur in the mammalian endocrine pancreas. Of the eleven peptides studied, insulin, pancreatic glucagon and somatostatin were present in endocrine cells within the islets of all the species investigated. The neuropeptide, vasoactive intestinal polypeptide, was located within nerve terminals innervating the islets in the Boidinae, Colubrinae, Elaphidae and Crotalidae but absent from the Natricinae investigated. No immunoreactivity was demonstrable with the antisera to substance P, met-enkephalin, C-terminal gastrin, bombesin, glicentin and gastric inhibitory polypeptide. Pancreatic polypeptide-like immunoreactivity was demonstrable only in the boid snakes and exclusively stained by a C-terminal specific antiserum.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 235 (1984), S. 669-673 
    ISSN: 1432-0878
    Schlagwort(e): Liver-cell heterogeneity ; Hepatic venous branches ; Karyometry ; Binucleate cells ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In untreated adult male albino rats nuclear volume and the percentage of binucleate cells were determined in the first layer of hepatocytes adjacent to hepatic venous branches of varying diameters (〈40 μm, 40 μm–80 μm, 80 μm–120μm, 120 μm–160 μm, 〉160 μm), and in the third and fourth layer of hepatocytes in the remainder of the perivenous parenchyma. In the first layer of hepatocytes adjacent to the vascular structures means of nuclear volume are significantly lower and percentage of binucleate cells significantly higher than in the cells of the remainder of the perivenous parenchyma. Within each area measured distribution curves of nuclear volume classes were homogeneous but showed heterogeneity in comparison with each other. The morphometric data presented in this study strongly support the opinion of the heterogeneity of liver cells in the perivenous zone, as previously postulated on the basis of histochemical investigations.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 43
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 305-315 
    ISSN: 1432-0878
    Schlagwort(e): Hepatocytes ; Rat ; Liver ; Circadian rhythm ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Subcellular structures of hepatocytes in periportal and perivenous zones were examined during 24 h. The volume, surface and numerical profile densities of cytoplasmic organelles were analysed morphometrically. Most subcellular structures in periportal and perivenous hepatocytes were subject to strong circadian variations. In hepatocytes from both zones, the volume densities of smooth endoplasmic reticulum (sER), mitochondria, lysosomes, peroxisomes, polysomes and lipid droplets demonstrated peak values at 16.00 h, 20.00 h or 00.00 h; trough values were at 04.00 h, 08.00 h, or 12.00 h, except for peroxisomes (16.00 h). However, the volume densities of glycogen granules and rough endoplasmic reticulum (rER) in periportal and perivenous hepatocytes exhibited maximal values at 04.00 h, 08.00 h or 12.00 h and minimal values at 20.00 h. The surface densities of sER, mitochondria, lysosomes and peroxisomes, and the numerical profile densities of mitochondria, lysosomes and peroxisomes in periportal and perivenous hepatocytes showed similar trends. These events suggest that membranes of the rER show a partial correlation with the sER, mitochondrial and lysosomal membranes during the 24-h span. This may involve the interaction between ribosomes and rER. Almost all cytoplasmic organelles examined displayed significant differences between periportal and perivenous hepatocytes, morphometrically and in fine structure, indicating that the morphofunctional variability of hepatocytes differs depending on the location in the liver acinus.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 321-325 
    ISSN: 1432-0878
    Schlagwort(e): Triiodothyronine ; Radioautography ; Mitochondria ; Liver ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary To assess the distribution of the thyroid hormone triiodothyronine (T3) within intact living cells, freshly prepared dispersed rat hepatocytes were incubated with [125I]-T3 for periods of 5 min and 30 min. Lightand electron-microscopic (EM) radioautography was carried out to determine the distribution of grains over the isolated cells. Both procedures showed the grains distributed almost entirely over the cytoplasmic matrix rather than the nucleus. Grain counts under the EM were compared with expectation based on established quantitative methods. Only the mitochondria showed obvious and statistically significant grain counts, whereas the nucleus failed to accumulate grains in excess of expectations by chance alone based on area. The findings support the existence of mitochondrial binding of T3, presumably a prerequisite for its action in direct stimulation of the mitochondria.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 45
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 351-355 
    ISSN: 1432-0878
    Schlagwort(e): Lymph node ; Steroids ; Macrophages ; Intercellular junctions ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Intercellular junctions were often found between macrophages in sinuses of regional lymph nodes of the rat after injection of large doses of cholesterol, cortisone acetate, and estrone at the footpad. They were identified by subplasmalemmal densities, 20–50 nm in width, beneath the plasma membranes of apposed macrophages. No distinct filamentous structures were visible in those dense regions. Electron-dense amorphous materials are lined up at the center of the intercellular space in the junctional regions. Some macrophages form clusters with intercellular junctions. No significant difference in the effect of cholesterol, cortisone acetate, and estrone on the number of intercellular junctions betwene macrophages was found.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 171-180 
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Ultrastructure ; Supraoptic nucleus ; Neuropil ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The neuropil located ventral to the SON was investigated by the use of immunoperoxidase staining for neurophysins, oxytocin and vasopressin, and electron miroscopy. The study was performed in six groups of rats: 1) control; 2) infusion of isotonic saline into the CSF; 3) infusion of hypertonic saline into the CSF; 4) drinking hypertonic saline for 4 days; 5) same as group 4 but injection of colchicine into the CSF on second day of dehydration; 6) salt loading for 3 months. In the control rats the ventral neuropil contained a few immunoreactive processes, the general morphology of which was completely different from that of the neurosecretory axons emerging from the SON at its dorsal aspect. In rats of groups 3 to 6 the ventral processes (VP) became loaded with neurosecretory granules, whereas the perikarya and axons were depleted. Based on their general morphology and reactivity pattern it is suggested that the VP are dendrites. Most of these “dendrites” were embedded in a glial cushion formed by the processes of a particular type of marginal glia. Some of these “dendrites” enveloped an arteriole penetrating the optic tract. All VP were rich in synaptic contacts. The possibility that the VP of neurosecretory cells may be functionally related to the subarachnoid CSF and the arteriolar blood flow is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 561-566 
    ISSN: 1432-0878
    Schlagwort(e): Pituitary gland, pars intermedia ; Peptide hormones ; Dopamine ; Corticotropin-releasing hormone ; 6-Hydroxydopamine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary When rats were injected with 6-hydroxydopamine the catecholaminergic nerve terminals in their intermediate lobes exhibited distinct signs of degeneration. Morphometric examination of the Golgi apparatus in cells of the intermediate lobe of these rats showed significant enlargement of Golgi cisternae. The release of adrenocorticotropin, β-endorphin/lipotropin and α-melanotropin from intermediate-lobe cells in vitro was measured by radioimmunoassay. The high basal peptide release was inhibited by dopamine and stimulated by methyl-isobutyl-xanthine. In contrast, γ-aminobutyric acid, serotonin, histamine and noradrenaline, or corticotropin-releasing hormone, rat hypothalamic extract and vasopressin had no or only very weak effects. These observations indicate that the synthetic apparatus of intermediate-lobe cells is constantly depressed by dopaminergic nerves. We were not able to stimulate peptide release from intermediate-lobe cells by use of the abovementioned endogenous agents.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 48
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 169-179 
    ISSN: 1432-0878
    Schlagwort(e): Foetal pancreas ; β Cells ; Insulin ; Fasting mothers ; Morphometry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary After maternal fasting for 72 h the pancreatic β cells of 18-day-old foetal rats show a conspicuous enrichment in secretory material, with an increase of pancreatic insulin concentration and a marked development of the rough endoplasmic reticulum and the Golgi apparatus. The morphometric analysis shows that the intracytoplasmic migration of the secretory granules is inhibited, principally inside the cell web. Consequently the number of secretory granules fused with plasma membrane decreases and this is associated with a decreased foetal plasma insulin. The difference in the ultrastructural aspect of the β cells of foetuses from fasting mothers and of foetuses from fed mothers is less conspicuous at 19 days of gestation and progressively disappears at 20 and 21 days. The modifications in ultrastructural aspect and in functional state are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 81-85 
    ISSN: 1432-0878
    Schlagwort(e): Retina ; Ibotenic acid ; Toxicity ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary After 2 h intraocular injections of 19 and 190 nmoles ibotenic acid in the rat retina produced an intensive vacuolization of the inner plexiform layer and cellular alterations, in the inner nuclear layer and ganglion cell layer. These alterations consisted of either cytoplasmic swelling accompanied by clumping of the nuclear chromatin or darkening of the cytoplasm along with nuclear condensation. A week later the retinas were thinner than the controls due to the disappearance of the affected cells. Pre-treatment with diazepam prevents the morphological alterations induced by 19 nmoles ibotenic acid; mainly the swelling, which was completely prevented, while the darkening was reduced drastically, although some vacuolization of the inner plexiform layer is still present.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 159-163 
    ISSN: 1432-0878
    Schlagwort(e): Ovary ; Rat ; Cell division ; Luteinizing hormone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effect of an LH pulse on the rate at which 3H-thymidine is incorporated into cultured ovaries of metestrous rats was studied. In comparison to ovaries cultured with tonic LH, an LH pulse (1) “rescued” follicles from atresia, (2) induced thecal cell proliferation, and (3) increased the rate at which granulosa cells enter mitosis. It is concluded that LH pulses increase follicular growth by first triggering thecal cell proliferation and then inducing mitotic divisions within the granulosa cells of both atretic and non-atretic follicles.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 51
    ISSN: 1432-0878
    Schlagwort(e): Choroid plexus ; Immunoglobulin G ; Permeability ; Anti-HRP-IgG ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The localization of autologous antiperoxidase immunoglobulin G (IgG) was studied in the choroid plexus of Lewis rats immunized against horseradish peroxidase (HRP). This experiment was performed to study the permeability of the choroid plexus to intravascular IgG. It was shown that autologous IgG was present in the extravascular spaces. The transendothelial transfer appeared to occur mainly via the fenestrations and some interendothelial junctions. No transfer of IgG at the level of epithelial cells toward the cerebrospinal fluid was demonstrated. Interstitial spaces in contact with the connective-tissue cells of the choroid stroma were strongly labeled. The significance of these spaces remains hypothetical and raises the question of the fate of IgG from the interstitial space.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 52
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 191-195 
    ISSN: 1432-0878
    Schlagwort(e): Glial fibrillary acidic protein (GFAP) ; Pituicytes, neonatal ; Development, ontogenetic ; Immunofluorescence ; Organ culture ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The appearance and intracellular localisation of glial fibrillary acidic protein (GFAP) in pituicytes in neural lobe cultures of newborn rats aged 7 to 30 days were investigated by use of the indirect immunofluorescence method. GFAP-immunoreactive cells were observed mostly in the outgrowth zone. GFAP was localised in the perikaryal cytoplasm as well as in pituicyte processes. GFAP-positive pituicytes showed considerable morphological polymorphism. The presence of GFAP — astrocytic marker — in pituicytes in vitro and the evident morphological similarity to cultured astrocytes suggest the astroglial character of these cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 53
    ISSN: 1432-0878
    Schlagwort(e): Cyclic guanosine monophosphate-phosphodiesterase (cGMP-PDEase) ; New cytochemical method ; Retina ; Rods, outer segments ; Light perception ; 5′GMPase ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cyclic guanosine monophosphate-phosphodiesterase (cGMP-PDEase) activity was studied histo- and cytochemically in the retinal rods of the rat with the use of a newly developed technique. Intense activity of cGMP-PDEase was evenly distributed over the outer segments of the rods. Reaction product was observed on the plasmalemma and on the disk membranes of the outer segments. A weak reaction product occurred also on the plasmalemma of the inner segments; however, no precipitate was found in the perinuclear and synaptic portions of the rod cells. The enzyme activity was strongly inhibited by 2 mM theophilline and by 2 mM 3-isobutyl-1-methylxanthine (IBMX). To confirm the specificity of this new cGMP-PDEase method, the localization of 5′nucleotidase (5′GMPase) was also studied. In contrast to the activity of cGMP-PDEase, the activity of 5′GMPase was distributed on the plasma membrane of the photoreceptor cells extending over a wide range from the synaptic endings in the outer plexiform layer to the tip of the outer segments.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 54
    ISSN: 1432-0878
    Schlagwort(e): S-100 ; Müller cell ; Astrocyte ; Development ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The rat retina was studied by immunohistochemistry with antibody to S-100 protein during the first three postnatal weeks. Immunoreactive astrocytes are first detected subjacent to the inner limiting membrane close to the optic disc. They gradually increase in number and spread toward the ora serrata along the inner surface of the retina as the development proceeds. S-100-immunostained Müller cells are first identified on the 12th postnatal day although their immunoreactivity is much weaker than that of astrocytes at the same stage. This differential intensity of the immunoreactivity of the two cell types facilitates observation of the entire shape of the astrocyte. This characteristic reveals that cellular investments of blood vessels in the inner retina are formed by astrocytic processes whereas those in the outer plexiform layer are derived from processes of Müller cells. The cellular investment becomes complete by the 18th postnatal day.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 55
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 559-564 
    ISSN: 1432-0878
    Schlagwort(e): Adrenal cortex ; Macrophages ; Ovariectomy ; Rat ; Estradiol administration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Macrophages of the adrenal cortex were studied in normal male and female, ovariectomized and estradiol-injected rats. In normal male rats few macrophages with numerous granules were observed in the zona fasciculatazona reticularis border, and in the zona reticularis. Granules, identified as lysosomes, were limited by a single membrane with a heterogeneous matrix; they exhibited acid phosphatase- and aminotriazole-resistant peroxidatic activities. A larger number of macrophages had identical distributions in normal female rats. In ovariectomized and estradiol-injected rats the number and distribution of adrenal macrophages were similar to those in normal females; however, in spayed animals the number of these cells in the zona reticularis was higher than in the other experimental groups. Lysosomes in macrophages of treated animals were more numerous and their contents more complex than in normal male animals. These results indicate that the adrenal macrophage system is stimulated in experimental conditions involving high levels of circulating estrogens.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 56
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 297-305 
    ISSN: 1432-0878
    Schlagwort(e): Sympathetic ganglion ; Development, ontogenetic ; Corticosteroid treatment ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Hydrocortisone injections into rats on postnatal days 3–9 caused an increase in the number of small granulecontaining cells in the superior cervical ganglia. These cells, corresponding to the small, intensely fluorescent cells, showed an extensive rough endoplasmic reticulum, a large Golgi apparatus and a very large number of granular vesicles. In addition to the granular vesicles, 70–160 nm in diameter, in which the dense core filled most of the vesicle, most cells of the hydrocortisone-injected rats contained also larger granular vesicles, up to 350 nm in diameter, in which the dense core was eccentrically located. A minority of the cells contained only granular vesicles 70–100 nm in diameter, which was the only type seen in the saline-treated control rats. Thirty days after discontinuation of the hydrocortisone treatment, most of the cells with large granular vesicles had disappeared, and only two profiles of such cells were seen on day 40. The other small cells contained only granular vesicles 70–160 nm in diameter, and these cells could not be distinguished from the small granule-containing cells of 40-day-old control rats treated early postnatally with saline. Hydrocortisone treatment, first on days 3–9 and subsequently on days 40–46, caused reappearance of the small granule-containing cells with large granular vesicles up to 350 nm in diameter, the dense core of which was eccentrically located. Hydrocortisone treatment on days 40–46 only was not followed by appearance of such cells in rats treated with saline on days 3–9.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 57
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 459-474 
    ISSN: 1432-0878
    Schlagwort(e): Meningeal compartment ; Perivascular space ; Brain intercellular compartment ; Cerebral cortex ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The intercellular clefts of the brain and the leptomeninges, and the perivascular spaces were studied with reference to the results obtained in a previous study (Krisch et al. 1983). The spatial relationships of these compartments were analyzed at the electron-microscopic level. Horse-radish peroxidase (HRP) was injected into the brain or into the contralateral ventricle. The pattern of distribution of HRP depends on the boundary situation in the individual compartments. The inner and outer pial layers accompany the vessels intruding into the brain. In the Virchow-Robin space the pial funnel obliterates within a short distance. The inner arachnoid layer is continuous with the outer arachnoid layer when it covers the vessels traversing the meningeal space. The perivascular compartment is not in communication with the arachnoid space; moreover, the pial funnel within the Virchow-Robin space is sealed off against the arachnoid space. Thus, blood vessels traversing the meningeal spaces and subsequently penetrating the brain surface are exposed to the common intercellular compartment represented by the intercellular clefts of the brain and the leptomeninges; this compartment does not communicate with the other compartments. The cerebrospinal fluid located in this intercellular compartment is preferentially drained into the upper cervical lymph nodes.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 58
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 635-642 
    ISSN: 1432-0878
    Schlagwort(e): Liver ; Endothelium ; Kupffer cells ; Peroxidase ; Cytochemistry ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Rat liver fixed by perfusion with low glutaraldehyde concentrations was incubated in diaminobenzidine-containing medium to stain for peroxidase. Endogenous peroxidatic activity was found not only in Kupffer cells but also in the endothelial cells lining the sinusoids and central veins. The reaction product was localized in the nuclear envelope and endoplasmic reticulum. The peroxidatic activity in endothelial cells showed a concentration-dependent sensitivity to glutaraldehyde: in liver samples fixed with 0.25% glutaraldehyde, approx. 23% of the sinusoidal endothelial cells and 65% of central vein endothelium were peroxidase-positive; with 0.5% glutaraldehyde, only approx. 8% of the sinusoidal endothelial cells contained detectable amounts of the reaction product; with 1.5% glutaraldehyde all endothelial cells were consistently peroxidase-negative. No peroxidatic activity could be found in liver endothelial cells following isolation by centrifugal elutriation. Endothelial cell peroxidase may possibly be involved in defense responses of liver and/or, as a part of prostaglandin synthase system, in prostanoid production.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 144 (1984), S. 59-66 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Araceae ; Hapaline ; Hapale ; Phymatarum ; Bucephalandra ; Flora of Borneo ; East Malaysia ; Sarawak
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract On the basis of newly collected and cultivated material full descriptions and illustrations are presented forHapaline appendiculata Ridl. andPhymatarum borneense M. Hotta.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 60
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 144 (1984), S. 67-71 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Scrophulariaceae ; Veronica fridericae spec. nova ; V. acrotheca ; V. farinosa ; V. armena ; V. multifida ; V. jacquinii ; V. caucasica ; V. filifolia ; V. oltensis ; Flora of Turkey
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Veronica fridericae spec. nova, described from the type locality in the S.E. Turkish province Van, is related toV. acrotheca andV. farinosa, both endemic to W. Iran. All 8 perennial species with pinnatifid leaves in S.W. Asia are presented in a key.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 144 (1984), S. 149-150 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Campanulaceae ; Campanula schimaniana spec. nova ; Flora of Afghanistan and of Pakistan
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Campanula schimaniana is a new species of sect.Campanula subsect.Rupestres, distributed in the westernmost mountains affected by monsoon.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 144 (1984), S. 151-153 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Compositae ; Asteraceae-Heliantheae ; Calea ; Chromosome numbers ; polyploidy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Chromosome numbers are reported for six taxa ofCalea, among them tetraploidC. septuplinervia, the only known polyploid inCalea s. str. The base chromosome number ofCalea is interpreted as x = 19.
    Materialart: Digitale Medien
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 144 (1984), S. 155-163 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Leguminosae ; Fabaceae ; Caesalpinioideae ; Mimosoideae ; Faboideae ; Phaseolus coccineus ; Serological systematics ; seed proteins ; phytohaemagglutinin ; vicilin ; phaseolin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An immunosystematical research was conducted on the seed proteins of 32 species ofFabaceae. By comparing all immunelectrophoretic patterns with the self reaction of a reference system (Phaseolus coccineus) all proteins detected have been identified and their distribution within the family has been analyzed. Half of the proteins identified inP. coccineus gave positive cross reactions with proteins present in all other species. Among this group are “protein I” and “phaseolin”. This result supports the homologization between phaseolin and vicilin. Among the other proteins, three are irregularly distributed throughout the family, and only three are restricted to a few taxa. This last group includes phytohaemagglutinin, which does not present any cross reaction outside the tribePhaseoleae.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 144 (1984), S. 209-220 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Triticum ; Elytrigia ; wheat ; Evolution ; genome ; karyotype
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The lengths of the A, B, and D genomes of common wheat,Triticum aestivum, were measured from the karyotype. Relative to the B genome, standardized as length 1.000, the lengths of the A and D genomes were 0.835 and 0.722, respectively. The lengths of the chromosome arms in the A and D genomes were then multiplied by the appropriate constants so that the total lengths of each genome also equalled 1.000. These calculations revealed that homoeologous chromosomes in wheat, with a few exceptions, have similar sizes and arm ratios. The arm lengths of the three homoeologues in each homoeologous group were then averaged. These average chromosomes turned out to be remarkably similar, in size and arm ratio, to their homoeologues in the E genome ofElytrigia elongata. This evidence and data on cross-compatibility and morphological characteristics suggested that the genusTriticum is a result of adaptive radiation from the perennial genusElytrigia, specifically from the complex of species possessing the E genome or one closely related to it.
    Materialart: Digitale Medien
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 144 (1984), S. 307-314 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Geraniaceae ; Erodium ; Monsonia ; Geranium ; Taxonomic revision ; Flora of Egypt
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A key is provided for the 14Erodium species of the Egyptian flora. The important differential chracters of leaf, inflorescence, flower, and fruit are discussed and illustrated.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 144 (1984), S. 315-320 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Fabaceae ; Lupinus palaestinus ; L. pilosus ; Breeding system ; insect induced self pollination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Significant increase of pod production occurs inLupinus palaestinus Boiss. andL. pilosus Murr. following insect visits. The cause of this increase is investigated through (1) examination of the biology of pollination, (2) examination of pod production under various pollination conditions, (3) examination of cross pollination by genetical markers. All data strongly suggest that “Insect Induced Self Pollination” is the main factor in the increase of pod production of these species in nature.
    Materialart: Digitale Medien
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  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 145 (1984), S. 1-13 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Triticum aestivum ; Aegilops longissima ; Cytogenetics ; homoeologous relationships ; chromosome substitutions ; translocations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The relationships of three wheat-Aegilops longissima chromosome addition lines A, C, and D with homoeologous wheat chromosomes were studied in PMC meiosis. Substitutions of alien chromosome A for wheat chromosome 6 B, chromosome C for 1 B and chromosome D for 4 B were obtained. The production of 4 BS/C and 7 BS/D chromosome translocations indicated cytogenetic relationships of C partially to homoeologous wheat chromosomes of group 1 and 4, and D partially to homoeologous wheat chromosomes of group 4 and 7.
    Materialart: Digitale Medien
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 145 (1984), S. 15-28 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Gramineae ; Hordeum spontaneum ; Wild gene pool ; factor analysis ; numerical taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Samples from 11 populations of wild barley,Hordeum spontaneum, from Israel, were examined for morphological variation in a “common garden” plot design. Earliness traits had the highest between population variation of all traits studied. No relationship was found between dimensions of leaves and size of seeds.—Using numerical taxonomy methods, four races were found, which correspond to the geographical and environmental range of the species in Israel. It is concluded thatH. spontaneum shows a well developed tendency toward formation of highly adaptive races rather than exhibiting clinical variation.
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  • 69
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Annonaceae ; Porcelia goyazensis ; Annona reticulata ; Winteraceae ; Drimys brasiliensis ; Giemsa C-banding ; structural heterozygosity ; karyotype evolution in tropical woody plants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract InPorcelia goyazensis (2n = 18) Giemsa C-banding patterns differ from those ofAnnona reticulata (2n = 14) and reveal structural heterozygosity. The amplitude of karyological variation in theAnnonaceae is greater than expected for a “primitive” woody family. In a comparison with other tropical angiosperm groups, the highly differentiated karyotype ofDrimys brasiliensis (2n = 86) is interpreted as being the end-point of numerous karyological changes.
    Materialart: Digitale Medien
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 145 (1984), S. 55-77 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Acanthaceae ; Bignoniaceae ; Bombacaceae ; Caesalpiniaceae ; Caryocaraceae ; Chrysobalanaceae ; Fabaceae ; Lobeliaceae ; Lythraceae ; Malvaceae ; Marcgraviaceae ; Mimosaceae ; Musaceae ; Onagraceae ; Orchidaceae ; Passifloraceae ; Proteaceae ; Rubiaceae ; Solanaceae ; Tiliaceae ; Zingiberaceae ; Flower nectar ; amino acids ; sugars ; evolutionary significance ; pollination biology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Individual amino acids and sugars from flower nectar of 32 plant species with different pollination systems were quantified and compared. Data show that there is no correlation between sugar and amino acid concentration. Furthermore there is no correlation between composition and concentration of amino acids and evolutionary advancement, nor any direct relation with pollination systems. However, higher sugar concentrations are often linked with more advanced morphological characters. Nectars from pierced or damaged flowers or nectars contaminated with pollen exhibit modifications and increases in amino acid composition. The presence of proline probably indicates such pollen contamination. Most pollinating animals depend on flower nectar in their energetic requirements, yet innumerable alternative amino acid and protein sources exist. Future research has to consider the relationship between nutritional requirements of pollinating animals and dependence on flower nectars.
    Materialart: Digitale Medien
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 145 (1984), S. 135-153 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Senecio vulgaris ; S. vernalis ; Autotetraploidy ; self-compatibility ; annual weeds
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Senecio vulgaris L. (2n = 40) is suggested to be of autotetraploid origin fromS. vernalis Waldst. & Kit. (2n = 20). This conclusion is based on results obtained from experimental hybridisations and cytological observations, and the consideration of morphological affinities, patterns of geographical distribution and hybrid formation under natural conditions. The morphological differences between the two species are related to a difference in the breeding system. WhilstS. vernalis is self-incompatible,S. vulgaris is self-compatible and strongly self-pollinating. Equally, other self-pollinating taxa traditionally associated withS. vulgaris are shown to have evolved independently from outbreeding relatives. Within a narrow frame of relationship, annual weeds have evolved in different cytotaxonomic circumstances.
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  • 72
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    Digitale Medien
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    Plant systematics and evolution 145 (1984), S. 165-168 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Solanaceae ; Datura innoxia ; Haploidy ; diploidy ; triploidy ; tetraploidy ; hexaploidy ; amino acid composition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In haploid, diploid, triploid, tetraploid and hexaploid cytotypes of the scopalamine-yieldingDatura innoxia, the amino acid profiles were studied. The results suggest that the amino acid composition is influenced quantitatively by increasing ploidy levels, but in an irregular way.
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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 145 (1984), S. 183-191 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Saxifragales ; Cunoniales ; Brunelliaceae ; Brunellia comocladiifolia ; B. mexicana ; Theales ; Caryocaraceae ; Caryocar brasiliense ; C. microcarpum ; C. villosum ; Karyosystematics ; paleopolyploidy ; tropical woody plants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Chromosome numbers are polyploid, 2n = 28 inBrunellia comocladiifolia andB. mexicana, and 2n = 46 inCaryocar brasiliense, C. microcarpum andC. villosum. The chromosome are small in both genera, with a length of ca. 1,6-0,4µm. Interphase nuclei correspond to the prochromosomal and the chromocentric type, respectively. This is in conformance with the systematic placement ofBrunelliaceae intoCunoniales, and ofCaryocaraceae intoTheales. Brunellia exhibits affinities to various other orders ofRosidae (andHamamelididae), and is suggested to be primarily apetalous. On a comparative basis, the chromosome numbers found in both families are interpreted as paleopolyploid (4 x and 6 x). This apparently is in correspondence with their rather primitive features, systematic isolation, relatively depauperate status, and evidently great age.
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  • 74
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 145 (1984), S. 193-201 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Ranunculaceae ; Aconitum ; Seed morphology ; seed coat SEM microcharacteristics ; taxonomic importance ; adaptative ecological significance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The seed coat morphology, investigated in taxa representative of the main European groups ofAconitum, are in good agreement with the current taxonomy of the genus. The seed coat microcharacteristics (warty epidermal cells) are very constant. There is a trend for the reduction of longitudinal wings on the edges concomitant with the development of ridges and transverse wings on the faces. Another morphological progression leads from smooth to rugulose and eventually to transverse wing-bearing seed faces. A working hypothesis suggests an ecological adaptative significance to these changes.
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  • 75
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 145 (1984), S. 223-226 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Theaceae ; Camellia japonica ; Allozymes ; polyploidy ; origin of cultivars
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Electrophoretic examination of allozymes from 189Camellia japonica cultivars revealed some banding patterns not explainable by codominant diploid genetics. At several loci encoding dimeric enzymes, 5 and 6 banded patterns were observed in 7 cultivars. These patterns are interpreted as resulting from triploidy or aneuploidy, where three variant alleles code for products which are electrophoretically distinguishable and associate to form three homodimers and three heterodimers. The presence of allozyme multiplicity in these clones suggests a sexual rather than a somatic mode of triploid origin.
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  • 76
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 145 (1984), S. 203-222 
    ISSN: 1615-6110
    Schlagwort(e): Fabaceae ; Leguminosae ; Medicago ciliaris ; Medicago intertexta ; Medicago muricoleptis ; Medicago granadensis ; Evolution ; chromosomes ; Pleistocene glaciations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Karyotype and external morphological analyses were conducted onMedicago ciliaris, M. intertexta, M. muricoleptis andM. granadensis which comprise theIntertextae section of the genusMedicago. All species were found to have 2n = 16 chromosomes (= 2 ×), including one pair of satellite chromosomes in each respective complement. Karyotypic evolution in theIntertextae involves changes in absolute chromosome size and in centromeric and relative size symmetry. Numerical taxonomic analyses were conducted independently on 17 karyotypic features and on 16 features of external morphology. The results of the two sets of analyses proved comparable, withM. ciliaris andM. intertexta forming a fairly close pair, and the remaining two species appearing to have more distant relationships to each other and to the first pair. These observations are consistent with the infertility relationships and chorologies of the species. It is suggested thatM. muricoleptis andM. granadensis are derived from theM. ciliaris/intertexta species complex withM. granadensis arising fromM. muricoleptis, or these two species independently evolving from a common species complex. Chromosomal and numerical analyses suggest thatM. ciliaris is the most primitive andM. granadensis the most derived species of theIntertextae.
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  • 77
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    Digitale Medien
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    Plant systematics and evolution 145 (1984), S. 243-258 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Lactuceae ; Microseris ; Canalized numbers ; additive polygenes ; evolutionary genetics ; pappus parts ; leaf shape ; isoenzymes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract CrossingMicroseris pygmaea (10 pappus parts) withM. bigelovii (5 pappus parts) results in hybrids with variable pappus part numbers between 5 and 10. Previous work has shown that a system of four additively acting genes determines the average pappus part numbers of these hybrids. In hybrid B87 two genes have a 10-determining and a 5-determining allele each, two others a 5-determining and a null (inactive or missing) allele. Genetic linkage of one of the latter with the enzyme geneEsterase-1 and the leaf shape genespatulate leaves has been demonstrated. Here we demonstrate linkage between one of the two 10-determining genes and the enzyme locusEsterase- Y/B. The genotypes in the pappus part system of many specimens can now be fully determined. This is a major advance for the analysis of the evolution of this additive polygenic system.
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  • 78
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Caryophyllaceae ; Silene latifolia ; S. alba ; S. pratensis ; Geographic variation ; racial differentiation ; clines ; morphological variation ; flavone glycosylation genes ; principal components analysis ; cluster analysis ; Flora of Europe
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Morphological and biochemical data were analysed from 30 greenhouse-grown populations of EuropeanSilene latifolia. Six separate character sets (flavones, seed, pollen, capsules, male and female flower morphology) were used in the analyses. There was broad-scale congruence between trends of geographic variation in most character sets, with the populations being assigned to western (or southern and western) and eastern clusters. The eastern and western clusters abut along a transition zone that runs roughly from Belgium to the northern Balkans; this zone represents a region of relatively rapid change and contains populations intermediate between the eastern and western clusters. Variation in flower morphology was weak and discordant with variation in the other character sets. The origin and maintenance of the variation pattern is discussed in terms of migrational history and “hybrid zones”.
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  • 79
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    Digitale Medien
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    Plant systematics and evolution 145 (1984), S. 291-309 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Cruciferae ; Brassicaceae ; Biscutella variegata complex ; B. laevigata complex ; Chromosome numbers ; variation ; aneuploidy and polyploidy ; chromosomal imbalance ; protogyny ; inbreeders and outbreeders
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Chromosome counts were determined for 46 populations ofBiscutella representing 28 taxa. The genus was found to contain diploid taxa with 2n = 12, 16 and 18, tetraploid taxa with 2n = 36 and hexaploid taxa having 2n = 54.B. laevigata L. s. l. consists of diploid and tetraploid populations which are poorly differentiated morphologically. TetraploidB. laevigata s. l. and hexaploidB. variegata Boiss. & Reuter (s. l.) are characterized by chromosomal instability. The variation in chromosome numbers and the occurrence of polyploidy is discussed in relation to the taxonomy of the genus. An investigation of the breeding system showed that most of the annual species were self-compatible and partly inbreeding and most of the perennial species self-incompatible and, therefore, outbreeding, while one annual species,B. cichoriifolia Loisel., showed both systems.
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  • 80
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 1-11 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Liliaceae ; Hyacinthaceae ; Scilla peruviana ; Gene mapping ; restriction enzymes ; ribosomal RNA genes ; rRNA/DNA hybridization ; polyploidy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Scilla peruviana biotypes have different chromosome numbers due to changes in the nucleolar chromosomes and polyploidy. We have examined two diploid (2n = 15 and 2n = 16) and two tetraploid biotypes (2n = 28 and 2n = 32). From the results of rRNA/DNA filter hybridizations it appears that rDNA percentages of the diploid biotypes are, approximately, 2.2-fold higher than those of the tetraploid biotypes. To examine the rRNA gene structure we have utilizedSouthern blot hybridization after DNA digestions with three restriction enzymes: Eco RI, Hind III and Bam HI. From the band analysis of both single and double digestions it has been possible to reveal the presence, in the diploid biotypes, of three gene types, heterogeneous both for length and for nucleotide sequences in the external spacer. The three rRNA genes are 12 600, 12 700, and 12 800 base pairs long and they have a different position of the Hind III sites in the external spacer. On the other hand, a single gene type of 12 600 base pairs, identical to the first type of the diploid biotypes, surprisingly exists in the tetraploid biotypes. Considerations on the rRNA gene regulation and evolution are made.
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  • 81
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 146 (1984), S. 13-30 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rutaceae ; Chromosome number ; karyotaxonomy ; base number ; karyotype variation ; literature critique
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Detailed chromosome counts have been made in 61 species, belonging to 33 genera ofRutaceae. 30 of these species are reported here for the first time. For 18 species at least one previous publication gives a chromosome number differing from that reported here. Such discrepancies are, in most cases, due to errors in counting or identification of the material. By critically reviewing the literature on each particular case, it appears possible to eliminate most of the false data. On the basis of the present results, the base number x = 10 is proposed for the genusRuta.
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  • 82
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 47-55 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Annonaceae ; Chromosomes ; polyploidy ; karyosystematics ; cytotaxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Information and illustrations on somatic chromosomes, structure of interphase nuclei and hair development are presented for 9 genera and 14 species ofAnnonaceae. A few suggestions tend to improve the unsatisfactory current classification. The spectrum of polyploids found in the family ranges from neo- to meso- and paleopolyploids.
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  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 146 (1984), S. 87-104 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Iridaceae ; Sisyrinchieae ; Tigridieae ; Trimezieae ; Basic numbers ; chromosome size ; karyotypes ; polyploidy ; karyotypic asymmetry ; bimodality ; DNA increase ; chromosome evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Although the South AmericanIridaceae are cytologically diverse, three tribes are distinguishable on the basis of karyotype morphology. TheSisyrinchieae andTrimezieae have variable basic numbers, ploidy levels and chromosome sizes, while theTigridieae are characterized by a relatively uniform basic number and bimodal karyotype. Changes in chromosome size within genera may suggest fluctuations in their DNA amount with latitude and altitude, particularly inSisyrinchium. The results are considered in terms of opportunities for more detailed research.
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  • 84
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 117-121 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Embryology ; megagametophyte ; antipodals proliferation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The structure of the grasses megagametophyte is considered to be characteristic enough as to deserve a particular place in the megagametophyte typology. Furthermore, it is compared with those of other Monocotyledonous families to point out embryological affinities.
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  • 85
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 105-116 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Myrtales ; Oliniaceae ; Olinia ; Embryology ; reproductive anatomy ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two of the five species ofOliniaceae (Olinia emarginata andO. ventosa), a monotypic and problematic family of theMyrtales, were investigated embryologically.Oliniaceae clearly agree with otherMyrtales in their basic embryological characteristics, and are characterized further by having an ephemeral endothecium, a campylotropous ovule, and a thick, three-five-layered, outer integument. A combination of these three characteristic features is unknown elsewhere inMyrtales, so that embryological features do not support a close relationship with any other member of the order. Shared distinctive anther characteristics (i.e. ephemeral endothecium) suggest thatOliniaceae are derived from the common ancestor ofCrypteroniaceae s. str.,Rhynchocalycaceae, Alzateaceae, andPenaeaceae.
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  • 86
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 141-143 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Lamiaceae ; Salvia tuxtlensis spec. nova ; Flora of Mexico
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Salvia tuxtlensis, sp. n., is immediately recognized by its semipersistent bracts and yellow flowers. Its affinities are not clear. It is endemic to the Soteapan area in the Sierra de Los Tuxtlas, in Veracruz, Mexico.
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  • 87
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 123-139 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Boraginaceae ; Rochelia ; Rochelia disperma ; Gynoecial development ; fruit development ; pseudomonomery ; systematics ; evolutionary trends
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The ontogeny of the gynoecium ofRochelia disperma has been investigated by LM and SEM. From the floral apex only one carpel primordium arises abaxially and eventually shifts into a subterminal position. Neither an initial stadium of a second carpel nor an adaxial vascular strand in gynobase and style could be observed. InR. stylaris two vascular strands run through the style and two undifferentiated lobes in adaxial position may be regarded as rudimentary mericarps. Only from comparison with related taxa the conclusion can be drawn thatRochelia is really pseudomonomerous, more so inR. disperma than inR. stylaris. The primary gynoecial bulge splits up into three parts inR. disperma: style/stigma, nutlets with gynobase, and disc. While the mericarps originate in mostBoraginoideae from the symplicate region and the ascidiate one is restricted to the very basal parts, inR. disperma the ascidiate part extends and forms the nutlets. The hood-shaped mouth of the carpel (the plicate zone) is closed to a triangular slit in lateral position, the stigma. The nutlets are triangular with broad base and do not surround the adaxial part of the gynobase inR. disperma, R. persica, R. bungei, R. stylaris, andR. macrocalyx. In contrast,R. peduncularis, R. cardiosepala, andR. cancellata have nutlets clasping the gynobase; they may be more closely related than was assumed up to now. The glochids ofRochelia are fascicled unicellular hairs (with different shapes) and not emergences as in theCynoglosseae. There is an evolutionary trend towards fruit formation with only one mericarp, especially inR. disperma.
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  • 88
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 171-179 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rosaceae ; Fragaria ; Restitution ; microsporogenesis ; polyploidy ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Double restitution has been observed cytologically for the first time in microsporogenesis of a F1 hybridFragaria virginiana ×F. chiloensis ♂. Restitution is probably due to irregularities affecting the spindle mechanism. Single or double restitution may depend upon the duration of the effect or upon the stage of meiosis affected. The occurrence of triades is indicative of a possible intracellular diversity. Although the reason which may cause restitution remains to be ascertained, maternal inheritance indicates an extrachromosomal cause.
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  • 89
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 181-195 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Myrtales ; Penaeaceae ; Penaea ; Saltera ; Embryology ; reproductive anatomy ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two species ofPenaeaceae (Penaea mucronata andSaltera sarcocolla), a unique South African family ofMyrtales, were investigated embryologically.Penaeaceae clearly agrees with otherMyrtales in its basic embryological characteristics, and further is characterized by its highly specialized features: ephemeral endothecium, 16-nucleatePenaea-type embryo sac, and unique ovular form. A wider range of affinities of families includingPenaeaceae, Oliniaceae, Rhynchocalycaceae, Alzateaceae, andCrypteroniaceae sensu stricto, as well as a possible common divergence from an ancestral line leading toLythraceae and/orMelastomataceae, are discussed on embryological and other grounds.
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  • 90
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 197-214 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Cactaceae ; Epidermis ; parallelocytic stomata ; stomatal types ; classification ; survey
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The stomatal types (i.e. the arrangement of epidermal cells in the vicinity of a stomatal pore in superficial view) have been examined in more than 150 taxa ofCactaceae, mostly using documented material. Preparations have been made by mazerating pieces of tissue with modified Jeffrey's Solution and staining with chlore-zinc-jodine.—The examined members of the subfamilyCactoideae showed parallelocytic stomata with only minor deviations in a number of cases. Members of the subfamiliesPereskioideae andOpuntioideae show parallelocytic stomata on the leaves, but the stomatas of the stem represent a different type, which apparently is not yet described. It is termed opuntioid here. In most cases the stomata are superficial but a few taxa show markedly sunken or “hidden” stomata.—In taxa of the subfamiliesPereskioideae andOpuntioideae the stomata are generally oriented parallel to the stem axis with only minor deviations. The stomata of taxa of the subfamilyCactoideae do in general not show a particular orientation with the notable exception of a number of epiphytic genera from the tribeHylocereeae.—The results of these investigations in general coincide well with the generic classification of theCactaceae byHunt (1967). A few cases where stomatal characters suggest a differing classification merit further investigations.—Additionally, the possibilities to distinguish between paracytic and parallelocytic stomata are discussed and an amended definition for the latter is given.
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  • 91
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 265-267 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Loranthaceae ; Phthirusa adunca ; Anther wall ; endothecial thickenings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The thickenings in the anther wall ofPhthirusa adunca are confined to the endothecium. This observation resembles the previous report onP. pyrifolia.
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  • 92
    Digitale Medien
    Digitale Medien
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    Plant systematics and evolution 146 (1984), S. 225-248 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Scrophulariaceae ; Campanulaceae ; Canarina ; Isoplexis ; Bird pollination ; ornithophily ; Flora of Macaronesia ; Canary Islands
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract (1) On the Canary Islands and Madeira typical bird-flowers occur in at least twelve species of six genera, although true flower-birds are absent. This inconsistency is in part elucidated by field observations on exotic and wild plants of Tenerife. —(2) In the Botanical Garden of Orotava it could be observed that various ornithophilous plants, which were introduced there, were visited by indigenous birds for nectar and in one case (Orthostemon) for food tissue. Of the three bird species involved, an endemic race of Chiffchaff (Phylloscopus collybita) and resident Blackcaps (Sylvia atricapilla) exploit, and pollinate, flowers legitimously, while the Wild Canary (Serinus canaria) is predominantly a destructive nectar robber. —(3) The insular Chiffchaff also proved to be a regular pollinator in the wild, at least ofCanarina canariensis andIsoplexis canariensis, two ornithophilous paleoendemics. Ornithophily, thus, is naturally practised on the island, though by birds basically insectivorous. —(4) A list of Macaronesian plants bearing the more or less complete ornithophilous syndrome is presented, including newly recognizedTeucrium heterophyllum andScrophularia calliantha. —(5) On biogeographical and faunistic grounds it is presumed that the modern visitors of Canarian bird flowers are secondary rather than the original partners of the continental tertiary flora in which these plants originated. Palearctic immigrants, when becoming resident on the islands during and since the Pleistocene, adopted facultative nectar feeding, entering an “orphaned” food niche. Casual flower visits in Europe suggest a certain predisposition of the Chiffchaff and the Blackcap for the exploitation of flowers. — (6) The ability of unspecialized birds to acquire nectardrinking spontaneously and to pass this habit on to their offspring, is demonstrated by a population of Tree Sparrows (Passer montanus) which have visited ornithophilousKniphofia (Liliaceae) in Berlin for several years.
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  • 93
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    Plant systematics and evolution 147 (1984), S. 1-27 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Gramineae ; Dispersal ; hygroscopic movements ; trypanocarpy ; diaspore ecology ; cerrado vegetation ; Flora of Brazil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract 28 grass species from one hectare of cerrado vegetation in Botucatu, State of São Paulo, were studied with regard to the morphology and dispersal of their fruits. 13 species have dispersal units with smooth surfaces which are predominantly dispersed by big herbivorous mammals or birds which swallow them together with their food, e.g., during grazing (accidental endozoochory). On the other hand, smaller animals, including birds, also feed directly on the grains; some of them may escape trituration and digestion or may be even stored (synzoochory). 11 species are principally epizoochorous: 8 of these are ± exclusively adapted to epizoochory, adhering to the animals by scabrid awns or sharply pointed calli, while the rest behave as epizoochores and anemochores. 4 other species are predominantly anemochorous with their dispersal units bearing soft hairs, sometimes together with very small scabrid awns; in a wet state they also can adhere to animals (occasional epizoochory). Beside this, most grass fruits can behave as passive ballists, as passing animals, wind and rain may cause their dispersal units to fall to the ground (passive autochory). — Among the 28 species, 12 have dispersal units which are awned. In 7 of them the awns are spirally twisted; the base of the dispersal unit runs out into a sharply pointed callus and has harpoone-like hairs. These awns show hygroscopical movements which may lead to a drilling of the basal part of the dispersal unit into the sandy cerrado soil. This trypanocarpy is important for establishment but without function for dispersal.
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  • 94
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    Plant systematics and evolution 147 (1984), S. 55-61 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Bombacaceae ; Malvaceae ; Hampea nutricia ; Seed morphology and anatomy ; aril
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The mature seeds ofHampea nutricia are glabrous, ovoid, arillate and dark tan in colour. Longitudinal streaks on the seed surface correspond to the underlying integumentary vascular strands. Testa and tegmen are derived from the outer and inner integuments, respectively. The outer epidermis of the tegmen forms a palisade-like macrosclereid layer, the inner epidermis a fringe layer. The endosperm is single-layered and also fills the space between the two cotyledons. The embryo is nearly straight, gland-dotted; it has asymmetrical and folded cotyledons, and gossypol ducts. Systematic position ofHampea is discussed and its placement inMalvaceae is supported.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 147 (1984), S. 29-54 
    ISSN: 1615-6110
    Schlagwort(e): Gymnosperms ; Cryptomeria ; Cunninghamia ; Metasequoia ; Sciadopitys ; Sequoia ; Sequoiadendron ; Taiwania ; Taxodium ; Marker chromosome ; karyotype ; polyploidy ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Various species ofTaxodiaceae were selected for chromosome studies to indicate cytotaxonomic and phylogenetic relationships. Point dispersal patterns of diagrammatic presentations of the species' karyotypes, rather than marker chromosomes, were found to be the most significant cytotaxonomic characteristic in indicating phylogenetic relationships. Karyotypic evolution inTaxodiaceae appears to occur by unequal reciprocal translocations followed by pericentric and paracentric inversions. Cytotaxonomic relationships among species generally correspond to the phylogenetic relationships withinTaxodiaceae indicated by classical taxonomic classification. Presence and types of marker chromosomes may have the potential to indicate relationships between different coniferous families.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 147 (1984), S. 63-78 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Exine morphology ; origin of sporophytic self-incompatibility ; palynology ; pollen wall
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In angiosperm pollen the reticulate-perforate exine sculpturing is associated with sporophytic self-incompatibility (S.S.I.) and imperforate and microperforate exine sculpturing is associated with gametophytic self-incompatibility. The earliest unequivocal angiosperm pollen conforms to exine morphology of pollen from plants with S.S.I. The orgin of S.S.I. is hypothesized to have coincided with the appearance of what is now the earliest recognizable angiosperm pollen. Other angiosperm characteristics correlated with S.I., functional stigmatic areas, large showy flowers (or aggregated inflorescences), and passive seed dispersal, provide some insight into the biological aspects of the earliest angiosperms.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 147 (1984), S. 79-90 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Onagraceae ; Oenothera hookeri ; Oe. suaveolens ; Megasporogenesis ; inheritance of callose pattern and polarity of embryo sac development ; embryology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The pattern of callose formation in meiotic cell walls and the order of megaspore degeneration and polarity during embryo sac development are investigated in F2-plants ofOe. hookeri ×suaveolens and the reciprocal cross. All investigated characters are variable between the ovules in the same ovary. Plants differ in the frequency of the types of callose pattern and polarity of the embryo sacs. In segregating progenies different combinations of both characters are found. The genetic basis of the polarity phenomena during the embryo sac development is discussed. In our material no correlation can be seen between the callose pattern in the surrounding wall of the meiotic cell and the development of polarity in the later stages.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 147 (1984), S. 103-118 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Limonium ; Plumbaginaceae ; Numerical taxonomy ; variation ; agamospermy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A taxometric analysis ofLimonium species in Western Europe has provided evidence for the subgeneric groupings proposed by other authors. A cluster analysis suggests that the origin of sexual and agamospermous species has taken place separately. Sexual and agamospermous species are usually clustered separately. The lack of a sexual process in many agamospermous species, as indicated by the distribution of incompatibility morphs and by very low pollen fertility, suggests that the evolution of sexual and agamospermous taxa has been by different processes. It is suggested that following the origin of agamospermous species or species groups by hybridisation, subsequent evolution in the agamospermous taxa has occurred by asexual means. Evidence from the distribution of pollen/stigma incompatibility morphs, especially the existence of self-compatible agamospermous species supports this hypothesis.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 147 (1984), S. 91-102 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Onagraceae ; Clarkia xantiana ; Electrophoresis ; isozymes ; phylogenetic models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Electrophoretic variation in isozymes coded by 40 loci was examined in two self-pollinating populations, one with white and the other with pink flowering plants, and four outcrossing populations ofClarkia xantiana (Onagraceae) native to California. The study was carried out to test theMoore & Lewis (1965) hypothesis that the pink selfer originated from the sympatric outcrossing population and then gave rise to the white selfer. The hypothesis could be rejected if one or the other selfer was more similar genetically to an allopatric population than to the sympatric one. Both selfers were monomorphic at all loci whereas the outcrossing populations were polymorphic at nearly half of them. The two selfers had the same genes at 32 loci but had different ones at eight loci. The pink selfer was not more similar to the allopatric populations than to the sympatric one, consistent with theMoore & Lewis model. The evidence also supported their proposal that the white selfer originated from the pink one and not independently. The electrophoretic evidence was valuable because it permitted qualitative comparisons (presence versus absence of particular alleles) between the selfer and the several outcrossing populations; such analysis was not previously possible because the latter populations are morphologically and cytologically similar.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 147 (1984), S. 119-123 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Melastomataceae ; Nodal and petiolar vascularization ; common gap and split laterals ; flank bridge ; cortical bundles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The nodal anatomy inMelastomataceae is variable. The (two times) unilacunar one trace type is wide-spread. In addition, species ofHeterocentron and ofTribouchina exhibit one pair of common gaps with split laterals. Others possess a distinct “flank bridge” of vascular tissue. Species with internodes quadrangular and four-winged in transsect exhibit up to five concentric cortical bundles per wing; they are involved in both petiolar vascularization and formation of flank bridges.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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