ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Genetics  (597)
  • Wiley-Blackwell  (597)
  • American Institute of Physics
  • 1985-1989  (462)
  • 1980-1984  (135)
  • 1960-1964
  • 1955-1959
Collection
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 2 (1981) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0192-253X
    Keywords: nuclear differentiation ; cytoplasmic inheritance ; Paramecium tetraurelia ; mating type ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In P. tetraurelia each cell is determined to express only one of the two complementary mating types, O and E. This determination is under cytoplasmic control and seems to be achieved only by the commitment or noncommitment to the expression of mating type E. All the previously known mutations affecting the differentiation of mating type prevent the expression of the E mating type (O-restricted mutations) without affecting the determination process. An E-restricted mutation was obtained: mtFE. Its phenotypic properties indicate that the mutation affects the determination process itself. When an O cell becomes mtFE/mtFE it acquires the E mating type and an E-determining cytoplasm. We propose that this constitutive determination for the E mating type is due to the inefficiency of a factor which is normally active in an O cell. This factor would act like a repressor and stabilize the E functions under an inactive state.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 2 (1981), S. 279-290 
    ISSN: 0192-253X
    Keywords: temperature-sensitive mutant ; cytokinin ; hormonal metabolism ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Developmental controls of morphological mutants of Phaseolus vulgaris L. conditioned by two independent loci, DL1 and DL2, were examined through grafting experiments and hydroponic studies. Phenotypes of mutant classes were duplicated by unions of scions and stocks derived from different genotypes. Results indicate that DL1 and DL2 regulate a root and shoot factor respectively, contributing to the mutant types. The allelic dosages of DL1 in the root and DL2 in the shoot rather than the genotype of the whole plant per se determine the severity of the mutant expression. Plants heterozygous for both loci with a temperature-sensitive expression of the mutant phenotype were used to determine physiological components involved. The primary abnormal developmental event associated with the appearance of mutant phenotypes, the restricted root growth at high temperature, could be overcome by the addition of cytokinin in hydroponic solution. These observations suggest that DL1 and DL2 may be related to the regulation of hormonal function or metabolism.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 2 (1981) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0192-253X
    Keywords: suspensive and adhesive teratoma cells ; teratoma embryoid bodies ; cell differentiation ; endogenous prostanoid biosynthesis ; long-chain fatty acyl CoA derivatives ; mass fragmentography ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Attachment of the cell surface to a substratum may play a critical role in initiating some cellular developmental commitments and in sustaining differentiation of cells that have already been specialized. Embryoid bodies of teratoma OTT6050 were divided, on day 10 of initial culture, into myogenic adhesive cells which were already (at day 6) characterized by endogenous prostaglandin (PG)I2 formation and little-specialized suspensive cells which formed only thromboxane (TX)B2 in the same culture system. Since at day 10 both cell types reached a stationary phase in which the nature of each cell was mature enough for the analyses with mass fragmentographic technique and gas chromatography- mass spectrometry (GCMS), the total levels of predominant long-chain fatty acyl CoA (acyl CoA) derivatives could be measured comparatively as methyl esters after methanolysis. It was found as a result of major differentiation that adhesive cells had a rather low ratio of arachidonyl CoA to stearyl CoA, although adhesive cells accumulated a larger total amount of acyl CoA derivatives than that accumulated in suspensive cells.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 2 (1981), S. 99-111 
    ISSN: 0192-253X
    Keywords: CIPC as a mitotic inhibitor of Dictyostelium ; inhibition of Dictyostelium development by CIPC ; CIPC-resistant mutants ; Dictyostelium ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The anti-mitotic herbicide isopropyl N-(3-chlorophenyl) carbamate (CIPC) prevents the growth of amoebae of Dictyostelium discoideum without killing the cells for a period of time equivalent to one generation. During in-hibition, amoebae accumulate in prophase and metaphase of mitosis. After removal of CIPC, they continue through mitosis and then divide.The addition of CIPC to amoebae under starvation conditions prevents aggregation and concomitant cell elongation. The cells, however, do not lose their ability to adhere to a surface, and they remain viable. When CIPC is added to amoebae which have formed streams, it leads to the disintegration of streams into small clusters of cells and to a loss of cell elongation.Post-aggregation stages of development can be inhibited by CIPC at the mound, slug, or Mexican hat stages. Slugs break apart into distinct aggregates.Mutants resistant to CIPC can be obtained easily. Among these mutants, many become temperature sensititive for growth (27°C) or development (27°C or 15.5°C). Others show various abnormalities at the normal temperature (22°C). Most mutants are cross resistant to the microtubule inhibitors nocodazole and thiabendazole, and some are also resistant to CIPC during development.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 2 (1981), S. 147-158 
    ISSN: 0192-253X
    Keywords: triplo-lethal locus ; Tpl ; gene-dosage ; X chromosome ; Drosophila melanogaster ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Only a single locus (Tpl) is known in the Drosophila melanogaster genome that leads to early lethality when present as a heterozygous duplication (three doses) or deficiency (one dose). We report the recovery of third instar larvae (and of occasional adults) carrying a duplication for the triplo-lethal locus, Dp(Tpl). Karyotype analysis of the larvae showed that the individuals surviving were almost entirely 3X;2A metafemales. We examined the question of whether the entire X or a single X locus was a major factor permitting survival. X-Y translocations were used to produce females hyperploid for different portions of the X and carrying Dp(Tpl). Analysis of metaphase chromosomes by quinacrine fluorescence pattern indicates that the X chromosome region between 6D and 7DE must be present in an extra copy to enhance the survival of Tpl duplication-bearing females. Another type of experiment suggests that it is the region between 7C and 7DE which is essential.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 1-6 
    ISSN: 0192-253X
    Keywords: glycerol-3-phosphate dehydrogenase ; isozymes ; mice ; genetics ; development ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Genetic variants that affect the heat stability and ionic charge of the adult isozyme of glycerol-3-phosphate dehydrogenase (EC 1.1.1.8) map to a gene, Gdc-1, located on chromosome 15. A second isozyme of glycerol-3-phosphate dehydrogenase, structurally homologous to the product of the Gdc-1 locus and expressed predominantly in undifferentiated tissues, has previously been identified. We have now discovered an electrophoretic variant of this embryonic isozyme. This expression is determined by a codominant allele of the gene, Gdc-2, that maps to the distal end of chromosome 9 as inferred from the observed gene order Mpi-1-d-Mod-1-Gdc-2.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 273-273 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 299-308 
    ISSN: 0192-253X
    Keywords: survival ; selection ; heat-shock proteins ; Drosophila melanogaster ; temperature compensation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Two stocks of Drosophila melanogaster, one sensitive (6.5% survival) and one resistant (76.24%) to heat shock (40°C/25 min) were derived through indirect selection [1]. Genetic analysis of heat-sensitive and heat-resistant lines we had selected revealed that the survival rate is chiefly determined by cytoplasmic inheritance but also depends to some extent on the nucleus [1]. The ability of the fly to survive thermal stress was found to have an excellent correlation with the kinetics of protein synthesis in ovaries or glands subjected to heat treatment. The incorporation rate of 35S-methionine into proteins was found to be higher for strains exhibiting higher survival (R1, R1S1) than for strains with a lesser ability (S1, S1 R1) to survive heat shock. Moreover, the intensity of labeling of the proteins synthesized and especially of the hsps (heat-shock proteins) after the heat shock is higher in the R1 and R1S1 stocks than in the S1 and S1R1 stocks. This convergence between survival and the cellular level of hsps (both manipulated by selection) bears on the physiological significance of these proteins which seems to participate in the control of the survival as an additive component.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 371-372 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 21-29 
    ISSN: 0192-253X
    Keywords: agouti locus ; embryonic lethal ; ax ; lethal nonagouti ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The time and mode of action of the homozygous ax gene, lethal nonagouti, has been investigated on the inbred AX/Pa background. Heterozygotes were mated inter se to produce 25% homozygous embryos and heterozygotes were mated with homozygous, nonagouti mice to provide control litters. Comparisons of the frequency of mating success, the ratio of implantation sites to ovarian ovulation sites, and the average litter sizes between experimental and control matings all indicated that ax/ax embryos are not lost prior to implantation. Histological examination of pregnant uteri indicated that ax/ax embryos are first evident as abnormal blastocysts at 4.5 days post coitum (pc). These implant and develop to varying degrees, some differentiating trophoblast giant cells and a primitive endoderm layer. Growth is retarded and only small, disorganized clumps of tissue remain by 7.5 and 8.5 days pc. The time and mode of gene action of lethal nonagouti is thus different from its allele, lethal Yellow.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 61-68 
    ISSN: 0192-253X
    Keywords: cell adhesion ; macromolecular ; sponge factors ; Dictyostelium ; adhesion-blocking antiserum ; staggerer mutant ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Cellular adhesion is what keeps cells together in multicellular organisms. Cells adhere to each other, to extracellular matrices, and to the substratum. Biochemical analyses of these processes have suggested some of the types of surface molecules which may be involved, but definitive evidence must rely on effective reconstruction of functional membranes or genetic alteration of the pertinent genes. Together these approaches may give us a better understanding of how cells sort out and form tissues during development.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 197-205 
    ISSN: 0192-253X
    Keywords: mouse fetal erythrocyte antigen ; erythropoiesis ; differentiation ; gene switching ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Bone marrow cells from normal adult mice were introduced by microinjection via the placenta into W/Wv genetically anemic fetuses of 11 days' gestation. After birth, erythrocytes were fractionated by fluorescence-activated cell sorting on the basis of antibody binding to a fetal-specific antigen (Ft). Lysates of Ft-positive, i.e., fetal, erythrocytes did not detectably contain hemoglobin of the donor type, as judged from electrophoresis of strain-specific hemoglobin variants. Thus, adult hematopoietic bone marrow cells did not resume fetal differentiation despite their post-transplant maturation in a fetal environment.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 255-272 
    ISSN: 0192-253X
    Keywords: salivary glands ; pupation stage ; protein synthesis and transport ; prepupal development ; developmentally regulated proteins ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Pulse-labeling experiments of salivary glands from the prepupal stages of development showed selectively high rates of synthesis of a set of low molecular weight proteins (6K-12K). These proteins are stably maintained in the salivary glands during prepupal development and are subsequently transported to the pupation fluid (found between the pupal case and the prepupal cuticle) when pupation occurs. These small polypeptides are very basic with the major components having isoelectric points of 8.6-8.7 and the minor components having isoelectric points of 9.1-9.5. This study shows the continuing function of the salivary glands - specifically, the synthesis and secretion of a set of proteins with a putative role in pupation.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 333-339 
    ISSN: 0192-253X
    Keywords: Drosophila ; chromosome ; polyteny ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A 315 kb walk in the genetically well characterized rosy region of the Drosophila chromosomes permits a molecular analysis of chromosome organization. Polytene chromosome bands in this region range from less than 7 kb to about 160 kb and the level of DNA replication is constant within bands and among bands and interbands. A good numerical and topographical correspondence is found between chromomeric units and genetic units.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 355-378 
    ISSN: 0192-253X
    Keywords: courtship ; learning ; biological rhythms ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Reproductive behavior in Drosophila involves a complex series of actions which is perturbed by many different kinds of mutations. Some of the most interesting courtship variants are those originally isolated with respect to disruptions of general learning and memory. Several types of genetically abnormal males have their “conditioned courtship” blocked or attenuated by the learning and memory mutations, some of which, in turn, are known to cause abnormal levels of specific monoamines or cyclic nucleotides. Recent studies of the defective courtship performed by the conditioning mutants involve “mosaic focusing” of the neural tissues affected by the behavioral/biochemical mutations. These experiments address the question of whether there are localized influences of the relevant genetic loci in their control of conditioned courtship, in spite of the fact that the protein products of the genes have a broad tissue distribution. Female responses to courting Drosophila males can also be dependent on the former's prior experiences. This pertains to enhancing aftereffects of prestimulation by the courtship song that is produced by a male; and the same learning and memory mutations, expressed in females, impinge on the normal aftereffects. One element of acoustical communication in courtship is a rhythmic oscillation in a particular component of the song. This short-term behavioral rhythm is altered in males expressing circadian rhythm mutations. To investigate the neural and cellular mechanisms by which these genes act, a mosaic analysis has been initiated on the ganglia affected by a clock mutation in its disruption of the courtship rhythm and of circadian cycles. A molecular isolation and identification of the normal form of this genecalled period - has also begun, in order to probe the locus's structure and function in detail. Such an investigation will include a comparison of the mosaic results with a direct determination of the various tissues in which the gene's product is expressed. In addition, interspecific transfers of the purified period gene will augment the current studies of species-specific features of the rhythmic courtship songs.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 425-438 
    ISSN: 0192-253X
    Keywords: polymorphism ; enzyme ; control gene ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A study was made of environmental and genetic factors affecting the quantity and disposition of the alcohol dehydrogenase (ADH) protein in Drosophila melanogaster. It was found that the amount of enzyme per fly is greatly influenced by the environmental conditions in which it develops. A critical factor is the concentration of yeast in the medium. A high concentration of yeast can double the quantity of ADH. The yeast appears to act through the provision of protein, and the protein to act through the provision of threonine, which is already known to induce ADH in fungi.Various genetic factors affect the quantity of enzyme. Males have more ADH than females. Files homozygous for the Fast allele have more ADH than those homozygous for the slow allele, and the difference is greater in females than in males. One particular line (ve), homozygous for Slow, has approximately half the normal quantity of enzyme, and the quantity segregates with the electrophoretic allele. Lines differ in the relative amounts of ADH in the gut (including Malpighian tubules) and the fat body. In general it seems that slow lines have relatively more enzyme in the fat body. In a cross between ve and a line homozygous to Fast, the difference in tissue distribution segregated with the electrophoretic allele. It is argued, but not demonstrated, that the differences in quantity and tissue distribution are due to nucleotide substitutions in noncoding regions close to, or within, the structural gene.It seems likely that the observed environmental and genetic differences in the quantity and disposition of ADH will influence the relative selective values of the electrophoretic genotypes.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 407-424 
    ISSN: 0192-253X
    Keywords: selection ; enzyme ; control-gene ; DNA polymorphism ; Drosophila ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The control of alcohol dehydrogenase (ADH) activity in natural populations of Drosophila melanogaster is chromosomally diverse and due to variation in allotype, enzyme level, and possibly post-translational modification. A comparative study of evolution in Adh structural gene variations with those loci modifying ADH expression has been carried out in large model populations maintained in environments that varied in temperature and food. Broadly based measures of gene expression were obtained as ADH activity and ADH protein level (determined immunologically) from individual flies whose allotype was also determined. The response to selection by “regulatory” or modifier loci compared with ADH allotypes was found to vary with environment, and its direction was not necessarily predictable from the kinetic properties of allele products. Selection for dominance modification of ADH activity in relation to Adh allotype was also observed. Analysis of genotype-environment interaction discerned two main types of response. Two major classes of chromosomal types, identified from restriction endonuclease map variations in a 12-kb region of DNA containing the Adh transcriptional unit, were present in the population. These two types of chromosome were in turn associated with the two types of interaction between genotypes and the environment. The results implicate polylmorphism for the control of genotypeenvironment interaction in populations, a genetically complex unit of selection, and a degree of evolutionary independence between structural and regulatory genes.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 5 (1984), S. 1-25 
    ISSN: 0192-253X
    Keywords: maize ; endosperm ; mutants ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 229-230 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 39-58 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; trisomy 3L ; dosage compensation ; heat shock ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Production of trisomic-3L Drosophila melanogaster has allowed further investigation of compensated levels of gene expression in autosomal trisomies. We find that four enzyme loci on this arm produce diploid levels of gene product in trisomic-3L larvae. For one of these genes, we show that all three alleles are expressed at similar levels. Two genes on 3L display dose-dependent levels of gene product, and their location, relative to the four compensating loci, indicates that these two classes of genes are not regionally separated. In trisomic-2R larvae, the level of enzyme produced from on 2R-linked gene was dose dependent. In contrast, measurements of five loci on the X chromosome in metafemales (X trisomies) suggest that most genes are compensated in these individuals. Heat-shock gene expression in trisomic-3L salivary glands was qualitatively similar to diploids. The quantities of the small hsps (from the 67B cluster on 3L) suggest that these four genes respond independently to the trisomic condition; two produce compensated levels of protein, whereas the other two produce dose-dependent levels of protein. The amount of hsp 83 produced in trisomies was similar to diploids (compensated). However, quantification of hsp 83 RNA showed that a dose-dependent level of transcript was produced. This implies that hsp 83 compensation is controlled post-transcriptionally.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 93-100 
    ISSN: 0192-253X
    Keywords: heat shock ; phenocopy ; forked ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Heat shock uncovers the recessive forked phenotype when heterozygotes between f36a and wild-type are heated during sensitive periods in pupal development. We call the phenocopy of a mutant in such a heterozygote a heterocopy. The heterocopy in f36a/+ is virtually identical to the mutant phenotype; however, bristles on different parts of the body are affected during different sensitive periods. We discuss the hypothesis that the heat shock acts by affecting expression of the wild-type gene product corresponding to the mutant gene. The sensitive period for heterocopy induction in a specific tissue is proposed to correspond to the normal time of gene expression for the forked gene product in a particular tissue.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 151-151 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    ISSN: 0192-253X
    Keywords: Dictyostelium discoideum ; revertants of stmF mutants ; cGMP metabolism ; cGMP-specific phosphodiesterase ; suppressor mutations ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: stmF mutants of Dictyostelium discoideum produce long, banded aggregation streams on growth plates and exhibit altered cGMP metabolism. To learn more about the role of cGMP in chemotaxis and the nature of the defect in these mutants, 15 nonstreaming (Stm+) revertants of two stmF mutants were isolated and characterized. Fourteen of the revertants continued to show the elevated cAMP-induced cGMP response and very low cGMP-specific phosphodiesterase (cGPD) activity characteristic of their stmF parents. Parasexual genetic analysis revealed that many of these Stm+ revertants carried phenotypic suppressors unlinked to stmF. One Stm+ revertant, strain HC344, exhibited a low, prolonged cGMP response and relatively high cGPD activity throughout development. To determine whether the elevated cGPD activity in this revertant resulted from increased enzyme production or enhanced enzyme activity, cGPDs were partially purified from the wild-type strain, the stmF parent and revertant HC344, and properties of the enzymes were compared. cGPDs from the stmF mutant and the revertant showed similar differences from the wild-type enzyme in kinetic properties, thermal stability, and sensitivity to certain inhibitors. These results suggest that stmF is the structural gene of the cGPD. In addition, the unusual cGMP response in revertant HC344 appeared to be due to increased production of an altered cGPD.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 213-238 
    ISSN: 0192-253X
    Keywords: ciliate pattern formation ; expression of mutations ; Tetrahymena thermophila mutations ; reversals of symmetry ; spatial organization of cell surface ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The initial changes of cell-surface organization that occurred as the recessive janAl (janus) mutation of Tetrahymena thermophila first became expressed were elucidated in a special mating scheme in which old macronuclei homozygous for janA+ were synchronously replaced by new macronuclei homozygous for janAl. During this period of onset of expression, the number, regularity, and asymmetry of the ciliary rows remained unchanged. New normal (primary) oral apparatuses (OAs) continued to be formed posterior to old OAs, as in normal cells. At about four fissions after conjugation, abnormal (secondary) OAs with a partial reversal of asymmetry began to appear nearly opposite to the primary OAs, close to but not at the eventual circumferential position of janAl secondary OAs. The array of contractile vacuole pores (CVPs), normally located adjacent to two ciliary rows centered near 22% of the cell circumference to the righ of the primary oral meridian, underwent a two-step transformation: first, the number of adjacent ciliary rows bearing CVPs increased to 3, 4, and sometimes 5, then “skipped” rows appeared within this broadened CVP-arc to split the single set of CVPs into two separated subsets. The CVP transformations occurred gradually and progressively. They began prior to the expression of secondary OAs but accelerated as secondary OAs appeared. As the CVP are became broader, its midpoint shifted somewhat to the right, away from the primary oral meridian, but ended up close to halfway between the primary and secondary oral meridians. The data provide a better fit to an intercalation model than to an alternative double gradient model, suggesting that the janAl mutation alters the large-scale organization of positional values by preventing the expression of a subset of these values and thus provoking reverse-intercalation of the remainder.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 293-293 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 297-297 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 7 (1986) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    ISSN: 0192-253X
    Keywords: Drosophila ; temperature effects ; heat-shock ; cell-lethal mutation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Pulses of various durations at temperatures between 29 and 38°C were applied to developing larvae of Drosophila melanogaster carrying the temperature-sensitive cell-lethal mutation 1 (1)ts726. The results show that it is not possible to reduce the time required for the induction of abnormalities in the mutant by treating larvae with heat pulses at temperatures higher than 29°C. Instead, treatment with high temperature leads to fewer abnormalities than 29°C treatments. Furthermore with high temperature treatments, the mutation has less effect on viability than is seen at 29°C. It is suggested that 1 (1)ts726 leads to abnormalities and death by a temperature-induced imbalance between different physiological or development events, rather than by interfering with the ability of the cell or the organism to withstand high temperature in general.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 59-74 
    ISSN: 0192-253X
    Keywords: Dictyostelium discoideum ; cell cohesion ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Three stage-specific cohesive systems operate in D. discoideum: VEG, elaborated by vegetative cells: AR, by aggregation competent cells; and PAR, by post aggregation stage cells. Previous study of a mutant strain JC-5 had shown the stability of its PAR system (but not the AR) to be temperature sensitive. However, the phenotypic expression of this mutation termed Coh A is complicated by the presence in that strain of a preexisting mutant gene Rde A, which accelerates developmental events generally and alters the pattern of morphogenesis. Genetic evidence presented here indicates that the two mutations have been separated by parasexual recombination yielding a Coh A, Rde A+ segregant class of which strain JC-36 is a prototype.At the permissive temperature, JC-36 follows a morphogenetic sequence like that of the wild type in respect to timing, morphogenetic pattern, and spore appearance. At the restrictive temperature, it forms normal aggregates at the usual time but exhibits two morphogenetic aberrancies during post aggregative development. First, fruit construction is arrested at a stage approximating the 16 hr “Bottle” stage of the wild type, though more squat and blunt tipped, and then the aggregate regresses. Cytodifferentiation into spores and stalk cells is also blocked. Second, a shift of slugs migrating normally at the permissive temperature to the restrictive causes the latter to disintegrate progressively as they leave clumps of cells behind them within the flattened sheath.JC-36 cells developing at the restrictive temperature also exhibited a decrease in EDTA resistant cohesivity attributable on two grounds to the sensitivity of the PAR system. In addition, the disappearance of the AR system completed in the wild type by the Mexicanhat (18-19 hr) stage is indefinitely arrested at an intermediate level in JC-36.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 113-132 
    ISSN: 0192-253X
    Keywords: eliminated DNA ; facultatively persistent sequences ; macronuclear development ; Tetrahymena thermophila ; phenotypic assortment ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: During conjugation in the ciliated protozoan, Tetrahymena thermophila, a somatic MAC-ronucleus develops from the germinal MICronucleus. Ten to 20 percent of the MIC genome is eliminated during this process. Three repetitive families have been identified which have different levels of repetition in the MIC and are eliminated to different degrees in the MAC. Some members of two of these families persist in the MAC. In this study, we have looked at these persistent sequences in the MAC of cell lines from a variety of sources including several inbed strains, two sets of caryonides, caryonidal subclones, and vegetatively aged cell clones. The results suggest that the sequences that remain in the MAC have a genetic predisposition to persist. However, epigenetic variations occur as the MAC develops so that only some of the persistent sequences are actually observed in a particular MAC. Polymorphisms may be generated if alternative processing of a single MIC segment occurs. These polymorphisms can later be resolved by phenotypic assortment during vegetative growth. These facultatively persistent sequences appear to differ from sequences previously described in this organism.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    ISSN: 0192-253X
    Keywords: ecdysteroid ; prothoracic gland ; temperature sensitive ; Drosophila ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The dominant temperature-sensitive mutation L(3)3DTS (DTS-3) in Drosophila melanogaster causes lethality of heterozygotes during the third larval instar at the restrictive temperature (29°C). Temperature-shift experiments revealed two distinct temperature-sensitive periods, with lethal phases during the third larval instar (which may persist for 4 weeks) and during the late pupal stage. At 29°C mutant imaginal discs are unable to evert in situ, but did evert normally if cultured in the presence of exogenous ecdysterone or when implanted into wild-type larval hosts. The only morphologically abnormal tissue present in the lethal larvae is the ring gland, the prothoracic gland being greatly hypertrophied in third instar DTS-3 larvae. Injection of a single wild-type ring gland rescued these mutant larvae, indicating that the mutant gland is functionally, as well as morphologically, abnormal. Finally, the mutant larvae were shown to have less than 10% of the wild-type ecdysteroid levels. These results are all consistent with a proposed lesion in ecdysteroid hormone production in DTS-3 larvae. A comparison with the phenotypes of other “ecdysone-less” mutants is presented.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 35-43 
    ISSN: 0192-253X
    Keywords: development ; isozymes ; murine trisomy ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We examined developmental changes in the relative activities of three different isozyme systems: aldolase, enolase and phosphoglycerate mutase, in tissues of fetal mice with trisomy 16 and of fetal euploid littermates. We wanted to determine whether morphological abnormalities such as reduced weight and size, which are generally observed in murine trisomy, are reflected at the molecular level. Following electrophoretic separation and subsequent measurement of relative activities of enolase isozymes in brain and phospho-glycerate mutase isozymes in heart, we found no significant differences between trisomy 16 fetuses and their euploid littermates. Synthesis of liver-specific aldolase was, however, delayed in trisomy 16 fetuses.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 83-89 
    ISSN: 0192-253X
    Keywords: chick blastula ; hypoblast-epiblast interaction ; transcriptional control ; α-amanitin ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Interaction between the epiblast and the primary hypoblast in chick blastula results in induction of the primitive streak (PS) in the epiblast. Alpha-amanitin, a specific inhibitor of poly A-containing RNA synthesis, inhibits formation of the definitive PS. This inhibition is associated with qualitative changes in the pattern of protein synthesis in the hypoblast but not in the epiblast. The protein pattern of the component areas of the epiblast shows increase in some polypeptides after treatment with α-amanitin. By contrast, α-amanitin resulted in a decrease in synthesis of several polypeptides, which are either undetectable or weakly present in the hypoblast. The α-amanitin-sensitive translational products of the embryonic genome that are observed in the hypoblast may have specific functions in the control of PS induction and stabilization.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 121-122 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 99-119 
    ISSN: 0192-253X
    Keywords: Drosophila ; tissue polarity ; frizzled ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The epidermis of Drosophila has a tissue polarity that is manifested by a parallel array of polarized structures (primarily hairs and bristles). The production of normal tissue polarity requires the function of the frizzled (fz) locus. We have isolated a large number of alleles at this locus and have phenotypically characterized more than 25 of them. We have found extensive allelic variation that a previous study failed to detect. Most of the alleles fall into a hypomorphic to amorphic series. Two alleles, however, have unusual properties. These alleles, which in general are moderately strong alleles, fail to produce a rough eye phenotype that is characteristic of all the other moderate or strong fz alleles. Thus, these two alleles are tissue specific in effect. Furthermore, these two alleles also have a neomorphic or antimorphic effect on hair polarity in one region of the wing.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 165-177 
    ISSN: 0192-253X
    Keywords: embryonic antigen ; tumor mutants ; oncodevelopmental molecule ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The 63-kDa antigen recognized by the monoclonal antibody F7D6 is present in all Drosophila embryonic cells and disappears from most tissues as each one reaches its final, differentiated state. Larval tissues lose the antigen around the time of hatching, imaginal tissues lose it during metamorphosis, and germ cells lose it during gametogenesis (Bedian et al: Devel Biol 115:105-118, 1986). The nervous system and spontaneously contracting musculature of the gut and gonads are exceptions and remain antigen positive at all stages. The F7D6 antigen appears to be associated with dividing, undifferentiated cells and electrogenic cells. This prompted us to test tumors for antigen presence. We tested four different recessive mutants that give rise to four different types of tumorous transformation: the embryonic tumor Notch, several larval melanotic tumors, the imaginal disc tumor 1(2)gl, and three alleles of the ovarian tumor otu. In all cases, tumorous tissues in homozygotes contained the F7D6 antigen. The electrophoretic mobility of the antigen appeared to be unaltered in tumorous tissues compared to normal cells, but the antigen is expressed at higher levels. The antigen is found on the cytoplasmic surface of plasma membranes and appears to be a marker of undifferentiated normal and tumorous cells. Similarities and differences between the F7D6 antigen and Drosophila c-src protein are discussed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. i 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    ISSN: 0192-253X
    Keywords: microinjection ; familial amyloidotic polyneuropathy ; fertilized egg ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To analyze the regulation of transthyretin gene expression we have produced transgenic mice by microinjecting cloned human transthyretin genes into fertilized eggs of C57BL/6 mice. The 7.6-kilobase (kb) human transthyretin gene containing about 500 base pairs (bp) in the upstream region was used for microinjection. Seven out of nine transgenic mice had detectable amounts of human transthyretin in serum when analyzed by enzyme-linked immunosorbent assay.Transthyretin mRNA was detected in liver and yolk sac but not in other tissues including brain. The amount of mRNA was variable among transgenic mice and was about one-tenth of mouse endogenous transthyretin mRNA. Human and mouse transthyretin mRNAs were detected in liver of fetus and yolk sac at 13 days of gestation and unlike yolk sac the level of mRNA in liver increased gradually during development and reached the maximum at around 17 days of gestation. Human transthyretin was associated with mouse transthyretin to form tetramers as judged from the dilution curve of enzyme-linked immu-nosorbent assay and the spur formation in Ouchterlony assay.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 281-293 
    ISSN: 0192-253X
    Keywords: mouse ; human ; cow ; maps ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Technological advances in the 1970s encouraged the mapping of homologous gene loci in different mammalian species, including mouse and man. One hundred eighty-five homologous loci have now been mapped in these two species. Conservation of linkage is sufficient to identify substantial segments of the two genomes that have been left intact since their divergence from a common ancestor. The recognition of these conserved segments allows experimental manipulation of mouse chromosomes or chromosomal regions to produce models of human chromosomal anomalies of medical importance.Comparative gene mapping has been extended beyond mouse and man and the genomes of some species, including domestic cattle, appear to be more highly conserved relative to humans than the mouse. Such species may be particularly useful in providing models of human chromosomal anomalies that cannot be duplicated in laboratory mice.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 23-35 
    ISSN: 0192-253X
    Keywords: maternal-specific transcripts ; genomic clones ; developmental RNA expression ; in situ chromosomal localization ; embryogenesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The unique cellular and genetic events which occur during the first few hours of Drosophila embryogenesis suggest that there are genes whose function is entirely or largely limited to this stage; this is supported by both genetic and molecular evidence. To identify some of these genes and characterize the relative contribution of specifically maternal and specifically zygotic transcription to early embryogenesis, we used competition and differential screening of a Drosophila genomic DNA library to obtain blastoderm- and maternal-differential sequences [Roark et al.: Dev Biol 109:476-488, 1985]. We describe here the Eco RI restriction fragments, chromosomal location, and size and developmental pattern of expression of the RNAs transcribed from 19 maternal-differential sequences. Five sequences encode maternal-specific transcripts (50-150-fold more abundant in maternal RNA than at any other stage). The maternal-specific and maternal-differential sequences are located at single sites on all major chromosome arms. Comparison of these sites with the sites of presently mapped maternal-effect genes shows several possible correlations, including one region containing three maternal-effect lethal mutations and two maternalspecific sequences.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 69-69 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 91-98 
    ISSN: 0192-253X
    Keywords: wing size ; miniature ; cell size ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To elucidate the mechanisms whereby genes and environment influence wing size, we investigated the effects of various rearing temperatures and larval crowding conditions on the wings of the mutant miniature and wild-type fruit flies. In adults we monitored wing size, cell number, wing thickness, cell density; in larval imaginal discs we looked for cell death. Cell density was inversely proportional to wing size. Of particular interest was the finding that smaller wings tend to be thicker. Electron microscope studies showed that the miniature wing layers are grossly abnormal. We hypothesize that these abnormalities are due to abnormal cell flattening of the wing epithelial cells, and we conclude that gene and environmental effects on cell flattening may be an important component in determining cell density and hence organ size.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 123-123 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 125-133 
    ISSN: 0192-253X
    Keywords: retrovirus ; embryonal carcinoma ; embryonic gene ; DNA methylation ; gene expression ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Northern blot analysis and in vitro nuclear transcription assays were performed in order to clarify conflicting reports on the expression of intracisternal A particle (IAP) genes in embryonal carcinoma (EC) cell lines. Results demonstrate that post-transcriptional mechanisms control the final steady-state levels of IAP RNA in EC cells. IAP genes were further found to be undermethylated in IAP-expressing EC cell lines.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 187-187 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 189-194 
    ISSN: 0192-253X
    Keywords: H-Y antigen ; skin grafts ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The influence of the major histocompatibility complex (MHC) on the survival of H-Y-incompatible skin grafts in rats has been determined by challenging normal and previously sensitized females of various isogenic and congenic strains with male trunk or ear skin isografts. The MHC's influence on the potency of H-Y has also been evaluated by determining the survival of male parental strain ear skin grafts on sensitized (with F1 hybrid male cells) F1 hybrid females of two different MHC congenic strains. The results indicate that, as in mice, the MHC has a dual affect on H-Y; it is involved in determining the ability of females to respond to the antigen as well as influencing its potency.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 233-247 
    ISSN: 0192-253X
    Keywords: DNA dispersion ; human β-globin ; reverse transcription ; evolution ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A human bacteriophage clone containing adult β-globin genes with four Alu sequences was microinjected to produce transgenic mice. Southern blot analysis on the spleen of a transgenic mouse revealed an unusual hybridization pattern that suggested extensive dispersion of human DNA throughout the mouse genome. This pattern was reproducible using several restriction enzymes, including a noncutting enzyme. The hybridization pattern was not observed in other tissues, and sequences were not detected in progeny using the bacteriophage probe. However, hybridization of spleen DNA of offspring against a human Alu probe revealed genetic transmission of human Alu sequences. The results suggest dispersion of microinjected Alu sequences throughout the genome.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 321-337 
    ISSN: 0192-253X
    Keywords: T-DNA ; T-cyt gene ; plant promoter structure ; plant development ; plant gene regulation ; plant defense-related mRNAs ; Agrobacterium tumefaciens ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 375-387 
    ISSN: 0192-253X
    Keywords: urease ; isozymes ; clones ; null mutants ; soybean ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The soybean (Glycine max [L.] Merr.) contains two urease isozymes whose expression is regulated in a tissue-specific and temporal manner. The ubiquitous urease is expressed in all tissues examined (leaf, embryo, seed coat, cell culture); the embryo-specific urease is synthesized exclusively in the developing embryo. The embryo-specific urease accumulates during seed development while the ubiquitous urease is found in highest levels during early development of both leaves and seeds. We have isolated mutants which fall in three phenotypic classes lacking one or both urease isozyme activities. Genetic analysis has thus far identified three unlinked loci which control the expression of urease(s). Genomic and cDNA clones of urease structural genes have also been recovered and we are working to assign these to genetic loci by sequence and RFLP analyses. That the ubiquitous urease isozyme is expressed in cell culture makes it possible to include cell culture in physiological and developmental studies. Additionally, we have developed direct selections for urease-negative mutants, and their revertants, in cell culture. These selections will facilitate the study of the expression of cloned urease genes in genetically transformed tissue.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    ISSN: 0192-253X
    Keywords: tubulin genes ; microtubules ; Arabidopsis thaliana ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Microtubules are important components of the cytoskeleton of plant cells and play key roles in plant growth and morphogenesis. Recent molecular studies have begun to elucidate the structure and expression of plant genes coding for the major components of microtubules, α- and β-tubulin. Tubulin amino acid sequences deduced from the DNA sequences of eight higher plant tubulin genes are 79-87% homologous with constitutively expressed mammalian tubulins. The genome of the model plant system Arabidopsis thaliana contains four dispersed α-tubulin sequences and at least seven β-tubulin sequences, only two of which appear to be linked. Of the five A. thaliana genes whose expression has been analyzed, the transcripts of one α-tubulin and one β-tubulin gene are constitutively expressed in roots, leaves, and flowers. A second α-tubulin gene is expressed predominately in flowers; the transcripts of the second and third β-tubulin genes are found predominately in leaves or in roots, respectively.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 1-12 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 37-48 
    ISSN: 0192-253X
    Keywords: eggshell ; female sterile mutant ; endochorion ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Four female-sterile mutants, fs(l)K451, fs(1)K1214, fs(1)K575TS, and fs(1)384, were studied in terms of chorion structure and chorion protein composition. The first three of these mutants cause morphological defects, ie, substantial underproduction and disruption of the endochorion, correlated with underproduction of the six major chorion proteins, s15-s38; the phenotypes are consistent with the observation that these mutants interfere with amplification of the major chorion genes that encode the s15-s38 proteins [Orr et al.: Proc Natl Acad Sci USA 81:3773-3777, 1984; Komitopoulou et al.: Dev Genet 7:75-80, 1986]. The fourth mutant, fs(1)384, and its alleles do not interfere with production of the major chorion proteins and the morphologically detectable bulk of the endochorion but lead to failure of endochorionic organization. Apparently this complementation group is responsible for a minor chorion product, which is evidently important morphogenetically and which is processed posttranslationally in a complex manner [Bauer and Waring: Dev Biol 121:349-358, 1987].
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 91-120 
    ISSN: 0192-253X
    Keywords: actin filament bundles ; ethyl methane sulfonate ; female sterile mutants ; in terallelic complementation ; oocyte determination ; ovarian tumor genes ; phenocritical thresholds ; polyfusomes ; polytene nurse cell chromosomes ; polytrophic meroistic ovaries ; pseudonurse cells ; Q-T-P-O values ; rhodaminyl phalloidin ; temperature-sensitive mutants ; transformed oocytes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The ovarian tumor gene behaves as if it encodes a product (OGP), which is required durirng several early steps in the transformation of oogonia into functional oocytes. Seventeen ethyl methane sulfonate-induced mutations have been studied, and their mutant phenotypes can be explained as graded responses by individual germ cells to different levels of OGP synthesized by the mutant germ cells themselves. The lowest and highest levels of OGP appear to be produced by otu10 and otu14, respectively. The 15 mutants with intermediate OGP levels are temperature sensitive; subnormal temperatures improve ovarian development, while above-normal temperatures suppress it. A subgroup ofthese mutants are unable to form a system of actin microfilament bundles in the cortical cytoplasm of their nurse cells during stage 10B, and these defective nurse cells are unable to transport their cytoplasm to the oocyte, as normally happens between stages 10B and 12. In addition to its role in the actin-mediated transport of nurse cell cytoplasm, OGP also appears to alter the morphology of giant polytene chromosomes, which form as the nurse cells undergo endocycles of DNA replication. Genetic evidence suggests that otu also encodes a second product (SP) that is utilized late in oogenesis. SP is required for the synthesis in the ooplasm of glycogen-rich, beta yolk spheres. Products of the otu gene also play a vital but unknown role in embryogenesis.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 181-191 
    ISSN: 0192-253X
    Keywords: cell interactions ; hematopoiesis ; mutagenesis ; SV40 ; fetal liver ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Several lines of transgenic mice were produced by pronuclear injection of a full-length cDNA encoding a mutant dihydrofolate reductase (DHFR, E.C. 1.5.1.3). The mutation causes altered enzyme kinetics for folate reduction as well as low affinity for methotrexate (MTX). One line of mice carrying the plasmid displays a moderate-to-severe anemia that is evident in fetuses and newborn mice and that moderates with age. RNA studies revealed high levels of transcription of the mutant gene in the fetal and adult liver, and low or absent expression in adult bone marrow. Transcription of the mutant gene was not found in the fetal liver of other pedigrees examined. The data thus suggest that expression of this mutant gene in the main hematopoietic organ of the fetus adversely affects erythropoiesis by altering the cellular environment for erythroid differentiation, and that translocation of the site of hematopoiesis to bone marrow, where the foreign gene is not expressed, leads to normalization of red cell production.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 213-213 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 683-698 
    ISSN: 0192-253X
    Keywords: variegation ; bristles ; pigmentation ; patterns ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In D. hydei two new mutants, In(1)f3 and IN(5)Z, show obvious mosaic gene expression. Their phenotypic expression is susceptible to the breeding temperature and to the addition of a supernumerary Y chromosome to the chromosome set. In this respect the mutants resemble standard cases of position-effect variegation based on the action of heterochromatin. However, since neither centromeric nor sex chromosomal heterochromatin apparently are involved, the mutations point to a new type of variegation provoked by euchromatic sections. The mosaic patterns of these mutants, in particular those of In(1)f3, will be described.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 129-142 
    ISSN: 0192-253X
    Keywords: glycerol phosphate dehydrogenase ; turnover ; Drosophila ; gene dosage ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In vivo radiolabeling of Drosophila melanogaster sn-glycerol-3-phosphate dehydrogenase (E.C. 1.1.1.8; GPDH) has been accomplished by microinjection of 3H-leucine into anesthetized flies. Comigration of immunoprecipitated radiolabeled GPDH with purified 14C-labeled GPDH-1 in SDS polyacrylamide disc gels has established the monospecificity of our immunoprecipitation technique. Short-term uptake experiments have demonstrated that maximum radiolabel incorporation of total TCA precipitable protein and immunoprecipitable GPDH-1 occurs within 4 hours postinjection, with GPDH-1 accounting for approximately 1% of the total radiolabeled TCA precipitable protein. In order to develop the parameters for turnover studies of GPDH in Drosophila, a comparative analysis of the rates of synthesis and degradation of GPDH-1 in flies bearing two and three doses of the structural gene have been conducted by the construction of adult flies aneuploid and euploid for the cytogenetic region 25F-26B on the left arm of chromosome II. Short-term uptake studies have demonstrated that the rate of GPDH-1 synthesis in the three-dose flies is approximately 1.58 times that found in the two-dose euploid flies. This value is in close agreement with data obtained for steady-state levels of CRM by rocket immunoelectrophoresis. In contrast, longterm pulse-chase experiments have revealed that rates of GPDH-1 degradation in these aneumploid and euploid flies appear to be identical. These data suggest that the rate of GPDH-1 synthesis in Drosophila is primarily regulated by a tightly linked cis-acting element which appears to act autonomously with respect to gene copy number as well as steady-state GPDH protein levels.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 165-176 
    ISSN: 0192-253X
    Keywords: X-chromosome inactivation ; digynous triploidy ; mouse ; post-implantation embryo ; late replication ; Cattanach's translocation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Using BrdU-labeling and acridine orange staining, the behavior of X-chromosome replication was studied in 28 XXX and 19 XXY digynous mouse triploids. In some of these the paternal and maternal X chromosome could by cytologically distinguished. Such embryos were obtained by mating chromosomally normal females with males carrying Cattanach's X chromosome which contains an autosomal insertion that substantially increases the length of this chromosome. In the XXX triploids there were two distinct cell lines, one with two late-replicating X chromosomes, and the other with only one late-replicating X. The XXY triploids were also composed of two cell populations, one with a single late-replicating X and the other with no late replicating X chromosome. Assuming that the late-replicating X is genetically inactive, in both XXX and XXY triploids, cells from the embryonic region tended to have only one active X chromosome, whereas those from the extra-embryonic membranes tended to have two active X chromosomes. The single active X chromosome was either paternal or maternal in origin, but two active X chromosomes were overwhelmingly maternal in origin, suggesting paternal X-inactivation in extra-embryonic tissues.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 207-214 
    ISSN: 0192-253X
    Keywords: germ line clones ; bithorax lethals ; dominant female sterile mutation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Three Ultrabithorax (Ubx) alleles and three different deficiencies of the bithorax complex (BX-C) of Drosophila melanogaster have been tested for maternal effects in the germ line. The dominant female sterile technique was used. The Ubx alleles and a deletion of the abdominal region of the BX-C are homozygous viable in germ line clones and show no maternal effects. Two deletions which lack the proximal portion of the BX-C are lethal in the female germ line indicating either that these deficiencies lack genes apart from the BX-C that are necessary for fertility or that there are BX-C genes that are essential for normal maternal germ line function. The significance of the bias in the isolation of only zygotic mutations at the BX-C are discussed with respect to these results.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 235-245 
    ISSN: 0192-253X
    Keywords: Drosophila ; chitin biosynthesis ; lethalcryptocephal mutation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Estimation of chitin deposition in the pupal and adult cuticles of adult Drosophila melanogaster during the pupal period is described. The timing of the periods of chitin deposition is compared with that deduced by previous workers using electron microscopy. The hypothesis that lethalcryptocephal mutant homozygotes are unable to evert their cephalic complexes at pupation because of excess chitin deposition is examined. The data obtained show no evidence that the mutation has any effect on chitin deposition.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 283-297 
    ISSN: 0192-253X
    Keywords: Dictyostelium discoideum ; cAMP-unresponsive mutants ; parasexual genetic analysis ; cell differentiation ; chemotaxis to folate and cAMP ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To find mutants of Dictyostelium discoideum that are unable to respond to exogenous cAMP signals (frigid mutants), amoebae of 218 independent aggregation-deficient mutants were treated in suspension with artificial pulses of cAMP and screened for the capacity to form EDTA-resistant cohesion sites. Eleven frigid mutants were identified and further characterized. Using parasexual genetic techniques, these strains were assigned to five complementation groups (fgdA-E) and the fgd loci were mapped in three linkage groups: fgdA and D in group II, fgdC in group III, and fgdB and E in group VII. Biochemical and physiological experiments with these strains indicated that fgd mutants are of two general types. When starved, strains in groups fgdB, D, and E failed to produce detectable levels of membrane-associated cAMP phosphodiesterase, surface cAMP receptors, or extracellular phosphodiesterase inhibitor, and the cells continued to respond chemotactically to folate. Thus, these strains are probably arrested in the vegetative phase or very early in development. In contrast, strains in groups fgdA and C produced low levels of cAMP receptors and secreted phosphodiesterase inhibitor. Moreover, after starvation, some of these mutants elicited a weak chemotactic response to cAMP. Therefore, unlike the former group of mutants, these strains appear to initiate development when starved, but the process is blocked at an early stage.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 3 (1982), S. 365-365 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 1-20 
    ISSN: 0192-253X
    Keywords: gene transfer ; mouse embryos ; genetic engineering ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    ISSN: 0192-253X
    Keywords: catalase ; Drosophila ; development ; turnover ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The ontogenetic and tissue-specific expression of catalase (E.C. 1.11.1.6) has been determined in a wild type strain of Drosophila melanogaster derived from a natural population. Two distinct peaks of activity are observed during development with the first peak occurring in late third instar larvae just prior to puparium formation, and the second and larger of the two peaks occurring during metamorphosis. These peaks of catalase activity are coincident with the two major peaks of ecdysone titer. Of the tissues assayed, larval malpighian tubules, gut, and fat body demonstrated the highest specific activities. Adult abdomen exhibited a two- to three-fold higher specific activity than either head or thorax. Of the abdominal tissues assayed, malpighian tubules and abdominal wall had the highest specific activities. Malpighian tubules were the only sexually dimorphic tissue with respect to catalase activity and are apparently largely responsible for an overall increase observed in female abdominal activity. Catalase-specific CRM levels parallel the enzyme activity levels indicating that these tissue-specific activity differences reflect differences in the rate of accumulation of catalase molecules.Turnover studies employing the catalase inhibitor 3-amino-1,2,4-triazole were conducted on head, thorax, and abdomen of male adult flies. Rates of catalase degradation were similar in the three body segments with a slightly higher rate in abdominal tissue. Therefore the different steady state levels observed largely reflect different rates of catalase synthesis.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 143-143 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 4 (1983), S. 185-198 
    ISSN: 0192-253X
    Keywords: maternal effects ; Polycomb locus ; Drosophila ; homoeosis ; Enhancer of Polycomb ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A mutation or deficiency of the Enhancer of Polycomb (E(Pc)) locus acts as a dominant enhancer of the adult mutant phenotypes of a group of similar homoeotic loci (Polycomb, Polycomblike, extra sex comb, and lethal(4)29). The E(Pc) mutation has a recessive lethal effect, and homo- and hemizygotes die as late embryos or larvae which appear cuticularly normal. E(Pc) also acts as a dominant enhancer of the embryonic homoeotic syndromes associated with Polycomb. Polycomblike, and lethal(4)29 mutations: its effect on the extra sex comb syndrome has not been effectively evaluated. At least for the interaction with Polycomb mutations, evidence is presented that the Enhancer of Polycomb locus has a maternal as well as a zygotic effect, and that its effect on Polycomb expression is not at the level of transcription. We suggest that the Enhancer of Polycomb locus acts specifically to regulate the activities of this set of homoeotic loci, and that E(Pc) recessive lethality results from noncuticular homoeotic defects which arise as a consequence of their reduced activity. In the context of this hypothesis, no present data allow us to distinguish whether Enhancer of Polycomb is a nonhomoeotic locus regulating the function(s) of Polycomb and related genes or is itself a homoeotic locus.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    ISSN: 0192-253X
    Keywords: chimera ; cell interactions ; sex reversed ; sex determination ; melanocyte ; intersex ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The manufacture of mammalian chimeras by aggregating embryos of different genetic constitutions makes possible the study of the genetic control of cellular interactions during embryonic development. Several different chimeric combinations have been made to study the role of the sex-reversed mutation in gonadogenesis and in gametogenesis. Sex reversed directs the gonad to become a testis and thus renders a SxrXX mouse sterile since gonocytes with two X chromosomes cannot complete gametogenesis in a testis. However, SxrXX gonocytes in the ovary of a female chimera become normal oocytes. The competitive interactions of genetically different melanoblasts in populating hair follicles and of primordial germ cells in populating the gonad have been revealed in chimeras. Chimeras have also been used to rescue inviable teraploid embryos and to permit teteraploid cells to display their differentiative capacities in normal tissue environments. We conclude that the genotype affects the capacity of cells to elaborate and to respond to inductive stimuli at each step in differentiation. The fine tuning of cellular interactions becomes apparent in chimeras made from embryos of different genotype.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    ISSN: 0192-253X
    Keywords: alcohol dehydrogenase ; Drosophila ; evolution ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The gene coding for alcohol dehydrogenase (Adh) in Drosophila melanogaster maps to 2:50.1 on chromosome arm 2L. It is expressed in both larvae and adults, coding for an abundant enzyme that plays a role in the detoxification of primary and secondary alcohols. In larvae the gene is most abundantly expressed in the fat body and gut. We have recently shown [49] that the major Adh transcripts differ in larvae and adults, the major adult transcript being initiated from a promotor several hundred pairs 5′ to the promotor from which the major larval transcript is initiated. However the coding region of the “larval and adult” mRNA are identical. We discuss recent studies of the transcriptional organization Adh and compare the structure of this gene in D. melanogaster with that in other species of Drosophila. The entire Adh gene and its surrounds has been sequenced from four species of Drosophila [45,48]. This data has been used not only for the study of phylogenetic relationships, but also of the types of sequence variation seen between species. The constraints on mutational change, especially with respect to codons, will be discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    ISSN: 0192-253X
    Keywords: retrovius ; chromosomal evolution ; feline genetics ; somatic cell genetics ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A combination of technical advances (most notably heterologous cell fusion, high resolution G-banding, and molecular cloning) has contributed to an accelerated advance in genetic analysis in mammals. The present human genetic map contains over 400 gene assignments and the map is growing rapidly as each new molecular clone or immunological reagent is developed. In our laboratory, we have developed a panel of rodent X human somatic cell hybrids that have been utilized in chromosome assignment of several classes of genes including oncogenes (ras, raf) and endogenous human retroviral sequences (ERVL, 2, etc). Using similar techniques, a biochemical genetic map of the domestic cat has been derived. The cat has 19 chromosome pairs and, to date, 40 genes have been mapped to 16 linkage or syntenic groups. Comparison of linkage relationships between homologous enzymes has revealed a striking conversation of chromosomal linkage association between cat and man. A comparison of syntenically homologous, highly extended high resoultion G-banded chromosomes between the two mammalian families revealed that 20-25%, by length, of the human karyotype can be precisely aligned (chromomere to chromomere) between cats and man despite the evolutionary divergence of the species nearly 80 million years ago.Moderately repetitive families of retrovirus-related DNAs exist within the feline and the human genomes. We have isolated molecular clones of several members of the feline RD-114 retrovirus family from a genomic library of normal cat cellular DNA. The endogenous sequences analyzed were similar to each other in that they were colinear with RD-114 proviral DNA, were bounded by long terminal redundancies, and conserved many restriction sites in the gag and pol regions. Several sequences were apparently deleted, relative to the previously characterized inducible RD-114 genome. The env regions of a number of endogenous RD-114 sequences examined were substantially deleted or diverged; a subset of these sequences contained information at the position of the env region that was not homologous to inducible RD-114. The RD-114 virogenes were dispersed to several cat chrosomes that were localized using a panel of rodent x cat somatic cell hybrids. A comparison of the genetic properties of endogenous human retroviral sequences revealed several similarities between the human and feline status of endogenous retroviruses.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 5 (1984), S. 43-58 
    ISSN: 0192-253X
    Keywords: ciliate genetics ; Tetrahymena malaccensis ; karyonidal inheritance ; macronuclear assortment ; selfing ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mating type determination in Tetrahymena malaccensis is karyonidal, ie, the four new macronuclei developing in a single conjugating pair are independently determined as to which of the six known mating types they will express. Occasional selfing clones are similar to those in T thermophila, in that any one is capable of stabilizing at a restricted range of mating types. The genetic basis of mating type potentialities is incompletely resolved. T malaccensis may, like T thermophila and T canadensis, have a single multiallelic locus that controls the array of types. Quantitative considerations suggest, however, that other loci may be involved.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 5 (1984) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 5 (1984), S. 83-91 
    ISSN: 0192-253X
    Keywords: temporal genes ; acid hydrolases ; liver ; mice ; hepatocytes ; nonhepatocytes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The cell specificity of expression of three distinct trans acting temporal gene systems determining the developmental control of α-galactosidase, β-galactosidase and β-glucuronidase was tested in mouse liver. For α-galactosidase and β-galactosidase, expression was limited to hepatocytes; no effect was seen in nonhepatocytes. For β-glucuronidase the data suggest that expression of the Gus-t temporal locus is also limited to hepatocytes, and that the smaller enzyme reduction seen in nonhepatocytes of some strains is due to a separate systemic regulatory locus that is also present in the [Gus] gene complex. We conclude that the temporal gene-determined timing mechanisms initiating switches in rates of enzyme synthesis are intrinsic to the cells themselves and are not communicated to adjacent cells. This conclusion applies to the temporal locus for β-glucuronidase that is proximate to its structural gene as well as those for α-galactosidase and β-galactosidase that are distant from the structural genes that they regulate.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 5 (1984), S. 117-127 
    ISSN: 0192-253X
    Keywords: temporal-regualatory variation ; isocitrate dehydrogenase ; rainbow trout ; Salmo gairdneri ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We examined a temporal series of embryos from 14 full-sib families of rainbow trout with starch gel electrophoresis to determine the time of initial detection of enzyme produced by ldh-3. Maternal enzyme was detected in unfertilized eggs, whereas paternal alleles showed evidence of initial expression after gastrulation and epiboly. Two alleles, 40 and 71, were expressed synchronously several days before the 114 allele. Measurement of enzyme activity by spectrophotometric analysis and serial dilution supported these observations. The degree of delay of expression of the 114 allele between families was coupled with other estimates of developmental rate. These data suggest the existence of allelic variation at a cis-acting genetic element controlling the pattern of ontogenetic expression of structural alleles at Idh-3.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; ts-mutants ; adenylate cyclase ; Phosphodiesterase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The mode of the developmental expression of adenylate cyclase (AC) and phosphodiesterase (PDE) in D melanogaster indicates that PDE plays the major role in the maintenance of a certain level of cAMP in postembryonic development, while both enzymes function in concert in imago. The ts-mutants ts155 and ts622, characterized upon their isolation as having an increased cAMP content and normal PDE activity, manifest high levels of AC activity from the third day of imago life. The levels of PDE activity characteristic for adult mutants with altered enzyme activity (low in ts66 and ts980, high in ts398) are manifested in ts980 from larval instar II, and from the larval instar III in ts398 and ts66. Data on the dependence of PDE activity in adults upon temperature of incubation, being in agreement with the expectations for a ts-mutation in a gene coding for a form of PDE in case of ts66, suggest that ts398 affects not the enzyme-coding gene but rather one for an activator protein. The fact that in ts398 (the polyphasic ts-lethal mapping to 1-38.9) 1) AC activity is somewhat higher than normal at 22°C and is readily activated at 29°C, 2) activity of PDE-I assayed in heat-pretreated homogenates is higher than normal, 3) that boiled extracts of ts398 are potent activators of the wild type and of its own PDE-I indicates that it is a mutation affecting calmodulin, which is known to be stable at boiling and capable of activating both AC and PDE-I. Data on Ca2+ and EGTA effects suggest that the mutation presumably increases Ca2+-binding activity of calmodulin, ts980 and ts622, in which ts-lethality could be produced only by certain doses of haloperidol and triftazine, appear to be lethal in compounds with ts398, thus indicating that these mutations could affect the same calmodulin-controlling gene.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 5 (1984), S. 201-207 
    ISSN: 0192-253X
    Keywords: rDNA ; compensation ; rRNA-DNA hybrids ; restriction analysis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The compensatory response is a regulatory event influencing the redundancy of the ribosomal RNA cistrons (rDNAs) of Drosophila melanogaster. In this report we attempt to demonstrate that the compensatory event and the thymidine analogue bromodeoxyuridine (BrdU) specifically interact. We conclude that the drug inhibits the compensatory response of Drosophila melanogaster XO males and argue that the compensatory event is not the passive consequence of replicational dominance known to occur in Drosophila polytene tissues.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 5 (1984), S. 239-239 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 1-25 
    ISSN: 0192-253X
    Keywords: developmental mutants ; axolotl ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Mexican axolotl (Ambystoma mexicanum) has enjoyed wide use in experimental embryology for over 100 yr. Its usefulness has been extended into the area of developmental genetics largely due to the contributions of R. Briggs and R. R. Humphrey at Indiana University. To date over 30 mutants have been described, almost all of which affect development. Some of these have been discovered in inbred strains while others have been uncovered in recent Mexican imports. These mutants can be subdivided into several major classes. Maternal effect mutations lead to deficiencies in informational, structural, or metabolic components of the egg essential to early development prior to the time at which the embryo's own genome becomes active. In contrast, the developmental lethals affect later stages in embryogenesis when both morphogenetic and biochemical events are determined exclusively by the genotype of the embryo. Most lead to death at about feeding stage. Some, the cell lethals, are believed to suffer from fundamental metabolic defects affecting all parts of the embryo. Others affect the development of specific organs or tissues. The developmental nonlethals also affect specific systems, but ones that are not essential to survival. Some affect the development and survival of pigment cells and these, along with isozyme variants, are useful as markers in developmental experiments.A number of the mutants have been studied in detail, but others scarcely at all. The purpose of this review is to bring them to the attention of all developmental biologists in the hope that their potential will be even more widely recognized.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    ISSN: 0192-253X
    Keywords: Tripsacum dactyloides ; Zea mays ; tripsacoid maize ; abnormal development ; ribosomal DNA ; restriction site change ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Some of the derivatives of a cross of maize (Zea mays L.) × Tripsacum dactyloides (L) L (2n = 72) have abnormal development leading to strange and striking morphologies. The Tripsacum chromosomes in these “tripsacoid” maize plants (with Tripsacum-like characteristics) were eliminated and the maize chromosomes were recovered through repeated backcrossing to maize. As an initial attempt to analyze the DNA alterations in tripsacoid maize, we have detected a few restriction site changes in the ribosomal DNA repeat of these plants (Hpa II, Bal I, Sst I, Mbo II, and Sph I) and a new Sph I site was mapped to the spacer region between the 26S and 17S genes. Several possible mechanisms for the generation of a new restriction site are discussed, and we propose that the transient presence of Tripsacum genome during the backcrossing in some way induced a rapid amplification and fixation of new restriction sites in a relatively short period of time.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 133-150 
    ISSN: 0192-253X
    Keywords: vitellogenesis ; Drosophila melanogaster ; egg shell ; oogenesis ; vitellogenin ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Ovarian follicle cells of wild type Drosophila melanogaster simultaneously secrete yolk polypeptides (YP1, YP2 and YP3) and vitelline membrane proteins. In order to understand the relationship between these two secretory activities, we have investigated the ultrastructure of a female sterile mutation that alters YP1 secretion and vitelline membrane deposition. Homozygous fs(1)1163 females lay eggs that collapse and contain reduced quantities of YP1. Secretory granules in follicle cells contain an electron-translucent component that is assembled into the developing vitelline membrane in both mutant and wild-type ovaries, and an electron-dense component that disperses after secretion in wild-type ovaries. Mutant ovaries differ from wild-type by (1) having larger secretory granules (2) forming clumps of the dense secretory component within the developing vitelline membrane (3) accumulating more tubules in the cortical ooplasm of vitellogenic oocytes, and (4) possessing altered yolk spheres. Mutant ovaries implanted into wild-type hosts showed no improvement in the secretory granules and slight improvement in the vitelline membrane clumps but amelioration of the oocyte phenotypes. Since genetic evidence suggests that the fs(1)1163 mutation resides in or near the Yp1 gene and biochemical data show that the mutation alters YP1 structure, we conclude that the ultrastructural phenotypes are due to a structurally abnormal YP1 in the mutant. The alteration in vitelline membrane structure caused by the dense clumps could account for collapsed eggs and, hence, the female sterility of the mutant.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 247-255 
    ISSN: 0192-253X
    Keywords: Drosophila ; triploid intersexes ; sex differentiation ; dosage compensation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Triploid intersexes homozygous for a mutant (msl-2) known to impede the hyperactivation of the X chromosome in diploid males differentiate into adults, sexually indistinguishable from their heterozygous sibs. A shift toward female sexual differentiation mediated by manipulating the rearing temperature is accompanied by an apparent increase in the level of an X-linked gene product. This unexpected result is rationalized in terms of differential lethality of individuals at the two extremities of the distribution of X-activity levels in intersexes raised at a particular temperature. No evidence of a mosaicism comparable to the sexual mosaicism exhibited could be found with respect to an X-linked gene product in triploid intersexes.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 281-291 
    ISSN: 0192-253X
    Keywords: DNA insertion ; reversion ; variegation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A spontaneous white mutation recovered in Drosophila mauritiana is unstable and reverts to normal eye color at a frequency greater than 4 per 1,000 ×-chromosomes. Germ line reversion occurs at a high rate in D. mauritiana males and in interspecific hybrid females, while the rate is depressed in D. mauritiana females. These events are not restricted to the germ line, as cases of variegated patterns of eye pigmentation, indicating somatic reversion, are recovered at a frequency comparable to that of the male germ line reversion rate. Germ line reversion events are genetically stable, while the somatic variegation patterns are not heritable. The patterns of eye pigment variegation produced suggests that reversion events are occurring throughout development. Whole genome DNA digests blotted and probed with the cloned D. melanogaster white gene indicate that this unstable white mutation in D. mauritiana is associated with an insertion of DNA that is lost upon reversion to wild type, indicating that this DNA insert is in fact a transposable element.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 7 (1986), S. 21-34 
    ISSN: 0192-253X
    Keywords: Drosophila ; pattern formation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The distribution of the soluble form of NADP+ -dependent isocitrate dehydrogenase (ICDH) was examined in Drosophila melanogaster imaginal discs. Development of the enzyme patterns and the specific transformations of the patterns by homoeotic mutants were studied. ICDH pattern formation was followed in eye-antennal discs and wing discs from the late 2nd instar stage through 3rd instar and 8 hours into prepupal development. The patterns formed gradually in both disc types. The most interesting pattern developed in the eye portion of the eye-antennal disc complex. ICDH distribution as well as staining intensity correlated well with differentiation of the ommatidia. The spatial distribution of ICDH within the discs was under genetic control. The patterns reflected the state of determination of the disc. When the presumptive tissue type was transformed via mutant homoeotic genes to different determinative states, the ICDH pattern likewise transformed to the pattern characteristic of the newly acquired structure.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 7 (1986), S. 35-49 
    ISSN: 0192-253X
    Keywords: zea mays ; embryogenesis ; defective kernel mutants ; genetic regulation ; maize ; leaf primordia ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The defective kernel (dek) mutants of maize are altered in both their embryo and endosperm development. Earlier studies have indicated that some of the dek mutants are unable to form shoot apical meristems or leaf primoirda. We have examined three embryo lethal dek mutants of this type, ptd*-1130, cp*-1418, and bno*-747B, to obtain a developmental profile for each. Allelism tests show that these three mutants are not allelic. Embryos were examined in early, mid-, and late kernel development as well as at kernel maturity by dissection and sectioning procedures and also at kernel maturity by scanning electron microscopy. All three mutants lag behind normal embryos in their rate of development. Embryos of ptd*-1130 reached the transition stage by early kernel development and progressed no further but underwent cell enlargement and necrosis during late kernel development. Embryos of cp*-1418 reached an early coleoptilar stage by midkernel development. They subsequently increased in size but did not form any leaf primordia. At kernel maturity, they no longer had a shoot apical meristem but often had a well formed root meristem. They appeared to remain healthy and did not become necrotic. Embryos of bno*747B reached the early coleoptilar stage by early kernel development but progressed no further. By kernel maturity, they had grown into masses of irregularly shaped embryonic tissue that no longer resembled any normal embryo stage but were not necrotic. None of these three mutants responded to attempts to support continued embryo development when cultured, but all three mutants formed callus on N6 and MS media supplemented with 2,4-D. These results indicate that these mutants are all uniformly blocked at specific stages early in embryonic development, have different subsequent developmental fates, and represent three different genes performing unique functions that are essential for embryogenesis.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 7 (1986), S. 81-97 
    ISSN: 0192-253X
    Keywords: Hawaiian ; Drosophila grimshawi ; yolk proteins ; ovarian follicle development ; fat body ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In analyzing the in vitro pattern of protein synthesis by the fat body and ovaries of the Hawaiian species Drosophila grimshawi, we have found that the ovaries synthesize much more protein than the female fat body and that the majority of the synthesized proteins are retained by the ovarian tissues. In contrast, the fat body secretes most of the proteins into the culture medium. Vitellogenins are the major class of proteins synthesized and released into the medium by both tissues. The synthesis of the three vitellogenin proteins (V1, V2, V3,) is noncoordinate in the two tissues. Ovaries synthesize much more of the V2 protein, less V1 and very little V3, whereas fat body synthesies more Vs1 protein with lesser qu antities of the other two. The follicle cells were identified as the site of ovarian vitellogenin synthesis in D. grimshawi, confirming the findings in D. melanogaster. In D. grimshawi, the three vitellogenins are synthesized by the follicle cells in a noncoordinate and developmentally regulated manner. V2 and V1 are the predominant proteins at the onset of vitellogenesis (S8-9); their production peaks together with that of V3 a few hours later (S10) and then decreases to quantitiesequalto that of V3 during early choriogenesis (S11). During active choriogenesis (S12), V2 and V1 cease to be synthesized, but V3 synthesis continues. The vitellogenins synthesized by the follicles in vitro are released into the medium and not incorporated into the oocyte.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 7 (1986) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 7 (1986), S. 177-185 
    ISSN: 0192-253X
    Keywords: sex reversal ; X-chromosome inactivation ; testis formation ; sex determination ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mice heterozygous for the T(X;16)16H translocation and carrying Sxr on their normal (inactive) X chromosome (ie, T16H/X Sxr individuals) may develop as males, females, or hermaphrodites. The proportion of males varied from 22% to 65% depending on the source of the normal X chromosome. A model is proposed, according to which relatively small variations in the spreading of inactivation from the X chromosome into the attached Sxr fragment produce large changes in the proportion of males. Testis weight in T16H/X Sxr males was found to be significantly smaller than in X/X Sxr males, irrespective of the source of the normal X chromosome.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 7 (1986), S. 205-221 
    ISSN: 0192-253X
    Keywords: gene dosage effects ; Drosophila sex determination ; maternal-zygotic gene interactions ; tandem duplications ; maternal effects ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The daughterless (da) gene provides an essential maternally supplied component for Drosophila sex determination and dosage compensation. In this connection, it is required as a positive regulator of a female-specific master regulatory gene, Sex-lethal (Sxl). In addition, zygotic da gene function is required for male and female viability. Thus, the phenotype da is complex; it includes both maternal and zygotic aspects, as well as both sex-specific and nonsex-specific aspects. Assessment of wild-type da function has relied on the characterization of only a single leaky mutant da allele. In order to better understand the nature of this allele and the relationships between the various aspects of its complex phenotype, tandem duplications of both the mutant and wild-type da alleles were isolated and used in a dose study of this gene's function. Three conclusions were reached: (1) by the most stringent genetic criteria, the mutant da allele is a simple hypomorph, an allele with reduced but non-zero levels of wild-type functions; (2) since increased dose of da+ had no effect on viability or progeny sex ratio, this gene seems not to be a dose-sensitive element of the X/A ratio sex determination signal; and (3) expression of the maternal da+ allele does make a contribution to the nonsex-specific developmental processes that require zygotic da+ function; however, that contribution is clearly minor. In contrast, the zygotic genotype with respect to da appears to have no effect on the expression of Sxl+ in the zygote, the sex-specific process that requires maternal da+ function.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 27-34 
    ISSN: 0192-253X
    Keywords: W locus ; mouse ; chromosome 5 lethal ; implantation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A recessive lethal mutant linked to Wsh causes the death of homozygous embryos between 4.5 and 5.5 days postcoitum (pc). Histological examination of implantation sites from intercross and backcross matings indicates that homozygotes are not all evident at 4.5 days pc, when embryos have begun to form trophectoderm giant cells and primitive endoderm, but are degenerating by 5.5 days pc, with only a few primary giant cells remaining after this time. The mutants thus form blastocysts that initiate the implantation process but the inner cell mass and polar trophectoderm fail to develop further. In vitro examination and culture of blastocysts indicated that the mutant homozygotes hatch from the zona pellucida and outgrow, although they do so somewhat more slowly than normal embryos. After 3 days of culture, the inner cell masses of mutant outgrowths may be smaller than normal. Since the gene has no known heterozygous effect and the primary gene function remains unknown, the mutant has been given the provisional symbol l(5)-1 for the first lethal on chromosome 5.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 45-58 
    ISSN: 0192-253X
    Keywords: white-mottled ; Malpighian tubules ; gene action ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Riboflavin deposition in organs of Drosophila hydei was studied by means of a growth test using a riboflavin-deficient strain of the fungus Aspergillus nidulans. In wild-type animals, riboflavin is deposited in Malpighian tubules (MT) and testes but not in adult eyes. Certain white (w) mutants do not contain riboflavin, whereas intermediately colored w mutants contain minor amounts of the substance. Riboflavin-containing MT cells contain special globules that can be fixed and stained with the redox dye phenazine-methosulphate. The number and size of these granules is related to growth effect and point to a role of the w locus in the intracellular deposition of riboflavin in special organs. In white-mottled (wm) position-effect variegation mutants, a significant correlation was found between the extent of variegation (percentage of yellow cells) and riboflavin content (growth effect) of the MT. However, the individual variation of cell phenotype was extremely large and exaggerated types were observed indicating “overdominance” of the rearranged w+ gene. This contradicts an unsubstantiated dogma of position-effect variegation that assumes that the affected gene simply switches between the on and off state, as is discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987), S. 73-82 
    ISSN: 0192-253X
    Keywords: isoelectric focusing ; corticosterone ; gene assignment ; alanine transferase ; tyrosine aminotransferase ; liver cytosol ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The amount of cytosolic glucocorticoid receptor in liver of Ts18, Tsl6, and Tsl9 vs euploid mouse fetuses was studied after incubation of [3H]dexamethasone with cytosol followed by isoelectric focusing on polyacrylamide gels. In addition, corticosterone concentrations and enzyme activities of alanine aminotransferase and tyrosine aminotransferase were measured in the cytosol of the livers. The amount of glucocorticoid receptor in the cytosol fractions of the livers was always higher in the Tsl8 than in the euploid fetuses of the same litter. It was also significantly (P 〈 0.0005) higher if pooled data from different litters were analyzed. The ratio of the glucocorticoid receptor in Ts l8 vs euploid mice varied between 1.3 and 4.7, with a mean of 2.1. In contrast, the glucocorticoid receptor levels in Tsl6 and Tsl9 fetuses were not different from the corresponding euploid controls. Comparing the corticosterone levels of the three trisomies tested with the corresponding euploid fetuses, no significant differences were found, indicating that the markedly elevated cytosolic glucocorticoid receptor concentrations in Tsl8 were not due to different corticosterone levels. This finding is consistent with the assignment of the glucocorticoid receptor gene to chromosome 18 in the mouse. There was no correlation betwen glucocorticoid receptor levels and the activity of the two glucocorticoid inducible enzymes tested in the liver of mouse fetuses.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 8 (1987) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...