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  • taxonomy  (81)
  • Drosophila melanogaster  (76)
  • Springer  (157)
  • MDPI Publishing
  • 2000-2004  (76)
  • 1975-1979  (81)
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  • 1
    ISSN: 1439-0361
    Keywords: Biogeography ; geographic variation ; taxonomy ; Amazilia ; Trochilidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die vorliegende Studie stellt die Ergebnisse von Untersuchungen zur Biogeographie, geographischen Variation, Habitatwahl und Taxonomie der Lesson-Amazilie (Amazilia amazilia) vor. Das Taxon umfaßt gegenwärtig fünf Unterarten, die von W-Ecuador bis SW-Peru verbreitet sind und überwiegend submontane Lebensräume besiedeln. Die Ventralfärbung unterliegt klinaler Variation; weiße Gefiederanteile nehmen von nördlichen zu südlichen Populationen ab, rotbraune Partien dagegen zu. Eigenständige morphologisch-morphometrische Kennzeichen sowie Unterschiede in den Habitatpräferenzen und in der Gesangsstruktur rechtfertigen es, die bisherige UnterartA. a. alticola als Paraspezies (A. alticola, Loja-Amazilie) anzuerkennen. Der Vulgärname weist auf den rezenten Verbreitungsschwerpunkt in den südecuadorianischen Anden hin. Aufgrund der engen Verwandtschaft bildenA. amazilia undA. alticola sowie die in Kolumbien endemische ArtA. castaneiventris eine Superspezies.
    Notes: Summary This paper reviews the biogeography, geographic variation, and habitat characteristics of the Amazilia Hummingbird (Amazilia amazilia). Based on morphological features, habitat preferences, and bioacoustics, I propose that the currently recognized subspeciesA. a. alticola should be regarded as a species distinct fromA. amazilia. Synapomorphic characters found in both taxa indicate membership of the same superspecies, together with the Colombian speciesA. castaneiventris. Considering the distributional focus ofA. alticola in the Andes of southern Ecuador, the English species name Loja Hummingbird is suggested.
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  • 2
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    Journal of ornithology 141 (2000), S. 275-284 
    ISSN: 1439-0361
    Keywords: East Asia ; taxonomy ; species delimitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Über die Gliederung der ostasiatischen Dickschnabelkrähen (Corvus macrorhynchos s.l.) in Biospezies besteht bisher keine einhellige Meinung. In dem großen Verbreitungsgebiet zwischen Indien, Japan und Timor werden gegenwärtig eine, zwei oder drei Arten anerkannt. Hier versuchen wir, in akustischen Merkmalen artanzeigende Merkmale zu finden. Eine Diskriminanzanalyse der Rufstruktur (76 Parameter) trennt dreiCorvus-Taxa (levaillantii undjaponensis aus der ‘macrorhynchos-Gruppe’,splendens) von der Südabdachung des Himalaya (Nepal, Kashmir) vollständig voneinander. BeiC. japonensis bleiben die trennenden Merkmale über große geographische Gebiete konstant. Die akustischen Unterschiede werden als taxonomisch relevant angesehen; sie zeigen Artgrenzen an. Folglich werden die Dickschnabelkrähen aus den Tief- und Hochlagen Nepals (Kontaktzone um 2 000 m) zwei Biospezies zugeordnet (C. japonensis undC. levaillantii), in Übereinstimmung mit morphologischen, ökologischen und parasitologischen Daten. Taxonomische Extrapolation der Befunde auf die Systematik anderer ‘macrorhynchos’-Populationen erscheint über die Rufstruktur (bis zum Fernen Osten Rußlands) und über Federling-Parasiten (Mallophaga) auf große Teile SO-Asiens möglich, bedarf aber für die stimmlichen Merkmale noch weiterer Klärung. Wahrscheinlich müssen immacrorhynchos-Komplex mindestens drei biologische Arten anerkannt werden (C. japonensis, C. levaillantii, C. macrorhynchos s. str.).
    Notes: Summary A discriminant analysis of the call structure completely separates threeCorvus taxa (levaillantii andjaponensis of the ‘macrorhynchos group’,splendens) inhabiting the southern slopes of the Himalayas (Nepal, Kashmir). The acoustic differences are considered taxonomically relevant, indicating species boundaries. Therefore the Jungle Crows of lower and upper Nepal (contact zone at around 2,000 m) are assigned to two biospecies (C. japonensis andC. levaillantii), as is consistent with morphological, ecological and parasitological data. It appears possible to extrapolate the findings regarding call structure to the systematics of other ‘macrorhynchos’ populations as distant as the Russian Far East, and those regarding mallophagan parasites to large areas of SE Asia; regarding the vocal characteristics, however, further clarification is needed.
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  • 3
    ISSN: 1572-8889
    Keywords: Drosophila melanogaster ; locomotor activity ; new method ; quantification ; food deprivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new method to quantify locomotor behavior in Drosophila is presented, and compared with previous methods. It is based upon a radar wave, reflected by moving flies. A problem associated with the new apparatus is that its output is dependent on fly size. However, for the case the weight of the experimental flies has been determined, a correction is proposed. The method has been used by studying the effect of starvation upon locomotion in Drosophila melanogaster. It was found that starved flies are much more active than well fed flies. The importance of this effect under several conditions is discussed.
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  • 4
    ISSN: 1572-9737
    Keywords: allozymes ; effective population size ; Drosophila melanogaster ; genetic diversity ; inversions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Preservation of genetic diversity is of fundamental concern toconservation biology, as genetic diversity is required for evolutionarychange. Predictions of neutral theory are used to guide conservationactions, especially genetic management of captive populations ofendangered species. Loss of heterozygosity is predicted to be inverselyrelated to effective population size. However, there is controversy asto whether allozymes behave as predicted by this theory. Loss of geneticdiversity for seven allozyme loci, chromosome II inversions andmorphological mutations was investigated in 23 Drosophilamelanogaster populations, maintained at effective population sizesof 25 (8 replicates), 50 (6), 100 (4), 250 (3) and 500 (2) for 50generations. Allozyme genetic diversity (heterozygosity, percentpolymorphism and allelic diversity), inversions and morphologicalmutations were all lost at greater rates in smaller than largerpopulations. Conservation concerns about loss of genetic diversity insmall populations are clearly warranted. Across our populations, loss ofallozyme heterozygosity over generations 0–24, 0–49 and25–49 did not differ from the predictions of neutral theory. Thetrend in deviations was always in the direction expected withassociative overdominance. Our results support the use of neutral theoryto guide conservation actions, such as the genetic management ofendangered species in captivity.
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  • 5
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    Conservation genetics 1 (2000), S. 67-76 
    ISSN: 1572-9737
    Keywords: mitochondrial DNA ; phylogeny ; phylogeography ; speciation ; species concepts ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 6
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    Journal of the history of biology 33 (2000), S. 27-70 
    ISSN: 1573-0387
    Keywords: ants ; E. O. Wilson ; Ernst Mayr ; systematics ; Systematics and the Origin of Species ; taxonomy ; William L. Brown ; William Morton Wheeler ; William Steel Creighton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , History
    Notes: Abstract Ideas about the natural world are intertwined with the personalities, practices, and the workplaces of scientists. The relationships between these categories are explored in the life of the taxonomist William Steel Creighton. Creighton studied taxonomy under William Morton Wheeler at Harvard University. He took the rules he learned from Wheeler out of the museum and into the field. In testing the rules against a new situation, Creighton found them wanting. He sought a new set of taxonomic principles, one he eventually found in Ernst Mayr's Systematics and the Origin of Species. Mayr's ideas tied together a number of themes running through Creighton's life: the need for a revised taxonomy, the emphasis on fieldwork, and the search for a new power center for ant taxonomy after Wheeler died. Creighton's adoption of Mayr's ideas as part of his professional identity also had very real implications for his career path: field studies required long and intensive studies, and Creighton would always be a slow worker. His method of taxonomy contrasted sharply not only with Wheeler's but also with two of his younger colleagues, William L. Brown and E. O. Wilson, who took over Wheeler's spot at Harvard in 1950. The disputes between these men over ant taxonomy involved, in addition to questions of technical interest, questions about where and how best to do taxonomy and who could speak withthe most authority. Creighton's story reveals how these questions are interrelated. The story also reveals the importance of Mayr's book for changes occurring in taxonomy in the middle of the twentieth century.
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  • 7
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    Mycoscience 41 (2000), S. 15-23 
    ISSN: 1618-2545
    Keywords: Agaricales ; Clitocybe trogioides var.odorifera ; Gerronema nemorale ; Psathyrella cineraria ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two new species and one new variety of Agaricales are described and illustrated from central Honshu, Japan:Clitocybe trogioides var.odorifera var. nov. (subgenusCystoclitus sectionCystoclitus), forming white, infundibuliform basidiomata, was collected from leaf litter in theQuercus-Pasania forests;Gerronema nemorale sp. nov. (sectionXanthophylla), forming small, olivaceous, omphalinoid basidiomata, was found on dead fallen twigs in theQuercus-Pasania forests;Psathyrella cineraria sp. nov. (subgenusMycophylla sectionArgillosporae), forming basidiomata covered by detersile, dark grey, fibrillose-squamulose veil, was found on decayed wood ofQuercus myrsinaefolia.
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  • 8
    ISSN: 1618-2545
    Keywords: Diaporthe kyushuensis ; grapevine swelling arm ; Phomopsis vitimegaspora ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Diaporthe kyushuensis sp. nov. is described and named as the teleomorph of causal fungus of grapevine swelling arm. The anamorph of the fungus isPhomopsis vitimegaspora.
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  • 9
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    Mycoscience 41 (2000), S. 115-122 
    ISSN: 1618-2545
    Keywords: distribution ; Pinus ; Quercus ; taxonomy ; Uredinales
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Asian pine gall rust, which has hitherto been assigned toCronartium quercuum distributed in North America, is described asC. orientale, sp. nov. The spermogonial and aecial states occur on hard pines, and the uredinial and telial states occur on various oaks.Cronartium orientale has globose, almost hyaline basidiospores in contrast to the ellipsoid, yellow-orange ones of North AmericanC. quercuum s.l. Characteristics of the new rust species in morphology, DNA analysis, and host alternation are discussed.
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  • 10
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    Molecular genetics and genomics 263 (2000), S. 144-151 
    ISSN: 1617-4623
    Keywords: Key words Post-replication repair ; N-ethyl-N-nitrosourea ; O-alkylpyrimidines ; Drosophila melanogaster ; mus308
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The mus308 locus of D. melanogaster was originally characterized by virtue of a mutant phenotype that resulted in specific hypersensitivity to cross-linking agents. However, the gene product has also been implicated in the repair of lesions other than cross-links. The gene was recently sequenced, and it encodes a protein with motifs characteristic of both DNA polymerases and helicases. We present mutability studies, using the recessive lethal (RL) test, which show that N-ethyl-N-nitrosourea (ENU) induces hypermutability in mus308-deficient conditions, although only in early broods. Further studies elucidated the role of MUS308 in repair processes by characterizing the spectrum of molecular mutations induced by in vivo ENU in postmeiotic germ cells, in mus308 conditions. These revealed that, in comparison to repair-proficient conditions, there is an increase in the frequency of GC → AT and AT → GC transitions, and AT → TA transversions. Moreover, frameshift mutations, which have not previously been reported to form part of the ENU spectrum, were also found. These results indicate that MUS308 is needed to process ENU-induced lesions, and support the hypothesis that the mus308 gene plays a role in post-replication bypass of O-alkylpyrimidines, probably mediated by recombination, which serves to increase the time available for error-free repair of these persistent and highly mutagenic lesions.
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  • 11
    ISSN: 1618-2545
    Keywords: China ; Leptographium ; morphology ; taxonomy ; Tomicus piniperda
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tomicus species (Coleoptera: Scolytidae) are serious pests of pines with a wide distribution in Europe, Asia and America. In Yunnan, south-western China,T. piniperda has destroyed more than 0.5 million ha ofPinus yunnanensis in the past 15 years. A blue stain fungus belonging to the genusLeptographium is associated with both the shoot-feeding and trunk-attacking stages of the beetle's life cycle. The fungus is morphologically similar to the anamorph ofOphiostoma crassivaginatum and toL. pyrinum, which are both characterised by short robust conidiophores and hyphae covered by a granular layer. Both these species have been isolated from conifers and are associated with insects. After comparing the fungus fromT. piniperda with similarLeptographium species, using light and scanning electron microscopy, we concluded that it represents a new taxon, which is described here asL. yunnanense sp. nov.
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  • 12
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    Biology and philosophy 15 (2000), S. 349-388 
    ISSN: 1572-8404
    Keywords: cline ; definition ; deme ; evolutionary synthesis ; experimental taxonomy ; J. Heslop-Harrison ; J.S. Huxley ; J.S.L. Gilmour ; nominalism ; systematics ; Systematics Association ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract The word ``deme'' was coined by the botanists J.S.L. Gilmour and J.W.Gregor in 1939, following the pattern of J.S. Huxley's ``cline''. Its purposewas not only to rationalize the plethora of terms describing chromosomaland genetic variation, but also to reduce hostility between traditionaltaxonomists and researchers on evolution, who sometimes scorned eachother's understanding of species. A multi-layered system of compoundterms based on deme was published by Gilmour and J. Heslop-Harrison in1954 but not widely used. Deme was adopted with a modified meaning byzoologists leading the evolutionary synthesis – Huxley, Simpson, Wright,and Mayr. Connections are shown between Gilmour's ideas around definingthe deme, his role in founding the Systematics Association, and his chapter``Taxonomy and Philosophy'' in the book The New Systematics. Thishistorical episode raises questions about the role of carefully-definedwords in scientific practice.
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  • 13
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    Mycoscience 41 (2000), S. 87-89 
    ISSN: 1618-2545
    Keywords: Cortinarius elatior var.albipes ; Cortinarius Sect.Defibulati ; new variety ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cortinarius elatior var.albipes var. nov., found in the deciduous forest is described and illustrated. It is distinguished from the type variety by having a white stipe and longer spores. The differences betweenCortinarius elatior var.albipes and similar taxa are briefly discussed.
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  • 14
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    Mycoscience 41 (2000), S. 167-169 
    ISSN: 1618-2545
    Keywords: East Asia ; freshwater fungi ; taxonomy ; tropical mycology ; Xylariales
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ceratostomella hyalocoronata is described and illustrated as a new species from old decaying wood immersed in a stream in Guangdong Province, southern China. It is compared toC. hyalostoma, a temperate terrestrial species.
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  • 15
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    Mycoscience 41 (2000), S. 379-388 
    ISSN: 1618-2545
    Keywords: arenicolous ; marine fungi ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Caryospora australiensis sp. nov.,Platystomum scabridisporum sp. nov. andSavoryella melanospora sp. nov. are described from driftwood collected from a sand dune at Rye, on the Mornington Peninsula Nature Park, Victoria, Australia. These species are compared with other taxa in these and related genera.
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  • 16
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    Mycoscience 41 (2000), S. 371-377 
    ISSN: 1618-2545
    Keywords: Platygloea ; Platygloeales ; Sigmogloea ; taxonomy ; Tremellales
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Specimens of two heterobasidiomycetous species, collected in Ontario and studied respectively by H. S. Jackson and R. F. Cain, are described as new; they arePlatygloea jacksonii andSigmogloea tremelloidea. P. jacksonii is characterized by small basidia and basidiospores and by sympodially developing conidia.Sigmogloea tremelloidea is an anomalous taxon with cylindric, mostly transversely septate (“auricularioid”) basidia, but some features suggest a possible relationship to the Tremellales.
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  • 17
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    Mycoscience 41 (2000), S. 407-410 
    ISSN: 1618-2545
    Keywords: Cortinarius purpurascens var.largusoides ; Cortinarius herpeticus var.fageticola ; Cortinarius Sect.Scauri ; mycoflora ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two species ofCortinarius Sect.Scauri collected in forests ofQuercus serrata andQ. mongolica var.grosseserrata, Q. serrata andFagus crenata, orQ. mongolica var.grosseserrata andF. crenata in Niigata prefecture were identified asCortinarius purpurascens var.largusoides andC. herpeticus var.fageticola, new to Japan. Macro- and microscopical descriptions of each species are given.
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  • 18
    ISSN: 1573-6857
    Keywords: aging ; Drosophila melanogaster ; fecundity ; male mating ability ; mutation accumulation ; senescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Evolutionary theories of senescence assume that mutations with age-specific effects exist, yet until now, there has been little experimental evidence to support this assumption. In this study, we allowed mutations to accumulate in an outbred, wild population of Drosophila melanogaster to test for age-specific differences in both male mating ability and fecundity. We assayed for age-specific effects of mutations after 10, 20, and 30 generations of mutation accumulation. For mating ability, we found the strongest effects of mutations in the first half of the life span after 20 generations, and at nearly all ages by generation 30. These results are qualitatively consistent with results from a companion study in which age-specific mortality was assayed on the same lines of D. melanogaster. By contrast, effects of fecundity were confined to late ages after 20 generations of mutation accumulation, but by generation 30, as with male mating ability, effects of novel mutations were distributed across all age classes. We discuss several possible explanations for the differences that we observe between generations within traits, and among traits, and the relevance for these patterns to models of aging as well as models of mate choice and sexual selection.
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  • 19
    ISSN: 1573-6857
    Keywords: bristles ; character specificity ; Drosophila melanogaster ; fluctuating asymmetry ; Notch gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Asymmetry has been used as a measure of developmental stability for bilaterally symmetrical organisms. Most studies have failed to partition the genetic and environmental contributions to the asymmetry phenotype due to the limitations of the systems used or the shortcomings in experimental design. The Notch mutants of Drosophila melanogaster were used to study the genetic contribution to asymmetry for six different bristle characters. Asymmetry response was character specific for the mutants examined. For N spl, N Co, N 264–47, Ax 71d, Ax 9B2, Ax E2, l(1)N B and nd 2 significant asymmetry responses, relative to wildtype Canton‐S, were observed for some characters. N 60g11 and nd 1 did not exhibit significant asymmetry for any of the characters examined. All of the mutants except N 60g11 and nd 1 showed thoracic bristle asymmetry. However, when asymmetry scores were pooled over the five bristle characters which individually exhibited fluctuating asymmetry, no significant differences were found between any genotypes. Therefore pooling asymmetry values across characters obscures the significant character specific asymmetry values observed. Thus caution is necessary when using the asymmetry phenotype of specific characters to draw organism wide conclusions about developmental stability.
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  • 20
    ISSN: 1573-6857
    Keywords: Drosophila melanogaster ; environmental stress ; genetic variation ; heritability ; high temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Variation of five quantitative traits (thorax length, wing length, sternopleural bristle number, developmental time and larva-to-adult viability) was studied in Drosophila melanogaster reared at standard (25°C) and high stressful (32°C) temperatures using half-sib analysis. In all traits, both phenotypic and environmental variances increased at 32°C. For genetic variances, only two statistically significant differences between temperature treatments were found: the among-sire variance of viability and the among-dam variance of developmental time were higher under stress. Among-sire genetic variances and evolvabilities were generally higher at 32°C but narrow sense heritabilities were not. The results of the present work considered in the context of other studies in D. melanogaster indicate different patterns of genetic variation between stressful and nonstressful environments for the traits examined. Data on thorax length and viability agree with the hypothesis that genetic variance can be increased under extreme environmental conditions.
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  • 21
    ISSN: 1573-8604
    Keywords: galago ; taxonomy ; vocalization ; morphology ; zoogeography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previous studies have shown the taxonomic value of vocal repertoires and hand (volar) pad characteristics in the classification of cryptic nocturnal primates such as bush babies. However, no study included quantitative comparisons within the geographical range of any one species. We investigated levels of intraspecific variation in calls and hand pad characteristics of the southern lesser bush baby (Galago moholi), using the northern lesser bush baby (Galago senegalensis) for interspecific comparisons. Examination of calls recorded from different regions along a transect of 1500 km across southern Africa revealed low levels of intraspecific variation in Galago moholi, whereas comparisons with homologous call-types in G. senegalensis revealed them to be significantly different. Volar pad measurements across the ranges of both species also showed low levels of intraspecific variation and relatively high interspecific variation. These findings demonstrate that vocal and volar pad characteristics can be used as consistent measures of difference between species that look almost identical. These methods provide a practical means of distinguishing between cryptic species, whether in the field, in captivity, or, in the case of volar pads, of preserved specimens.
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  • 22
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    International journal of primatology 21 (2000), S. 963-1019 
    ISSN: 1573-8604
    Keywords: mouse lemurs ; Microcebus ; taxonomy ; revision ; new species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genus Microcebus (mouse lemurs) are the smallest extant primates. Until recently, they were considered to comprise two different species: Microcebus murinus, confined largely to dry forests on the western portion of Madagascar, and M. rufus, occurring in humid forest formations of eastern Madagascar. Specimens and recent field observations document rufous individuals in the west. However, the current taxonomy is entangled due to a lack of comparative material to quantify intrapopulation and intraspecific morphological variation. On the basis of recently collected specimens of Microcebus from 12 localities in portions of western Madagascar, from Ankarana in the north to Beza Mahafaly in the south, we present a revision using external, cranial, and dental characters. We recognize seven species of Microcebus from western Madagascar. We name and describe 3 spp., resurrect a previously synonymized species, and amend diagnoses for Microcebus murinus (J. F. Miller, 1777), M. myoxinus Peters, 1852, and M. ravelobensis Zimmermann et al., 1998.
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  • 23
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    International journal of primatology 21 (2000), S. 381-420 
    ISSN: 1573-8604
    Keywords: phylogenetics ; taxonomy ; systematic ; Ateles ; Cebidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Our goal was to determine phylogenetic relationships among geographically and taxonomically distinct haplotypes of spider monkeys (Ateles) based on DNA sequence variation for the mitochondrial DNA control region and cytochrome c oxidase subunit II gene. We obtained samples from most previously recognized subspecies of Ateles, ranging from Central America throughout the Amazon Basin, to determine phylogenetic relationships among racially recognized groups. Comparison of DNA sequences using both parsimony analysis and genetic distance analysis produced phylogenetic relationships that were very similar for each genetic region. We analyzed the phylograms produced, along with associated bootstrap support, confidence probabilities, and genetic distances between taxonomic groups, to identify four monophyletic species of Ateles: Ateles paniscus, composed of haplotypes from the northeastern Amazon Basin; A. belzebuth in the southern Amazon Basin; A. hybridus, located primarily along the Magdalena River valley of Colombia; and A. geoffroyi, which includes two former species: A. geoffroyi and A. fusciceps. This arrangement is contradictory to long-held taxonomies of Ateles based on pelage variation and is similar to a recent analysis based on craniodental variation. Results of this investigation suggest patterns of gene flow, evolutionary relationships, and speciation patterns that are more plausible than previous pelage-based taxonomies, which required seemingly impossible patterns of gene flow. Conservation efforts aimed at protecting Ateles, one of the Neotropics most endangered genera, will also benefit from the findings presented in this paper.
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  • 24
    ISSN: 1573-8604
    Keywords: vocalization ; sexual advertisement ; predator advertisement ; taxonomy ; evolution ; mouse lemur ; primate ; Madagascar
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Advertisement calls are often important noninvasive tools for discriminating cryptic species and for assessing specific diversity and speciation patterns in nature. We investigated the contribution of these calls to uncover specific diversity in nocturnal Malagasy lemurs. We compared sexual advertisement and predator advertisement calls of two mouse lemur species, western gray and eastern rufous mouse lemurs (Microcebus murinus and M. rufus, respectively) living in two contrasting habitats (dry deciduous vs. rain forest), and analyzed them statistically. Both species emitted several highly variable whistle calls in the context of predator-avoidance. Intrapopulation variation was high and overlapped interspecific variation. Sexual advertisement calls, given in the mating context, displayed a totally distinct, species-specific acoustic structure. Whereas gray mouse lemurs produced rapidly multifrequency modulated, long trill calls, rufous mouse lemurs gave slowly frequency-modulated short chirp calls. Our results suggest specific status for gray and rufous mouse lemurs and indicate the importance of predation and social needs in shaping vocal communication.
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  • 25
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    Plant systematics and evolution 221 (2000), S. 107-112 
    ISSN: 1615-6110
    Keywords: Rosaceae ; Rosa ; Caninae ; epicuticular waxes ; taxonomy ; hybridism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Classification within the genusRosa is problematic due to ± continuous variation of morphological characters. The dogroses, (Rosa, sectionCaninae) are classified only by their unique meiotic system not by directly visible characters. The intrasectional structure remains insufficient, as the characters (glands, hairs and prickles) are known to exhibit great morphological divergence affected by both genetic plasticity and environmental influences. Taxonomy of dogroses follows a highly artificial system which allows us to identify morphospecies, which are not necessarily evolutionary species. However, SEM-studies in theCaninae revealed that all taxa of the subsectionRubiginosae are characterised by a granule type of epicuticular waxes, whereas members from the other subsections (with three exceptions) form triangular rodlets. Comparison with specimens grown under the same conditions confirmed these findings on natural populations and additionally revealed that following artificial hybridism, offspring develop the maternal type of wax structure due to the matroclinal inheritance in this section.
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  • 26
    ISSN: 1615-6110
    Keywords: Acacia ; classification ; Leguminosae ; morphology ; phenetics ; RAPD ; software ; taxonomy ; UPGMA
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    Topics: Biology
    Notes: Abstract The phenetic analysis of non-nodulatingAcacia species by Harrier et al. (1997) was repeated to illustrate how different computer programs may generate alternative UPGMA trees for the very same data, even in the absence of data input order effects (ties). For example, all Harrier et al.'s UPGMA dendrograms produced by software from the Scottish Agricultural Statistics Service differed from those obtained by the packages NTSYS and MVSP87. Particularly, the positions ofA. albida, A. rovumae, andA. pentagona, as well as the relationships betweenDiacanthae andTriacanthae were affected by this phenomenon. Hence, whenever clustering techniques are used, care should be taken to consider possible software-dependent caveats and artefacts. Nevertheless, all programs provided clusterings that largely coincided with the subgeneric and sectional groupings proposed by Vassal (1972) although the positions of some species varied depending on whether morphological or molecular data were considered (e.g.A. albida andA. rovumae).
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  • 27
    ISSN: 1615-6110
    Keywords: Leguminosae ; Papilionoideae ; Lonchocarpus ; leaflets ; secretory cavities ; false secretory cavities ; pellucid dots ; glands ; anatomy ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Abstract The occurrence of leaflet secretory cavities in 23 Brazilian species ofLonchocarpus was surveyed anatomically and compared with data from external morphology (presence of pellucid dots) to evaluate their taxonomic significance. This study revealed three cases: presence of secretory cavities associated with pellucid dots, pellucid dots corresponding to false secretory cavities, and absence of pellucid dots and secretory cavities. These results indicate that in this genus the “glandular pellucid dots” cited in morphological descriptions do not always correspond to secretory cavities, and that their nature must always be confirmed by histological sections. Secretory cavities have systematic significance at subgeneric taxonomic level for the genusLonchocarpus.
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  • 28
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    Plant systematics and evolution 224 (2000), S. 173-182 
    ISSN: 1615-6110
    Keywords: Gesneriaceae ; Streptocarpus ; Chromosome numbers ; growth patterns ; taxonomy ; Africa ; Comoro Islands ; Madagascar
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study records the chromosome numbers of 10 species ofStreptocarpus; nine of the counts are new. With the exception ofS. buchananii of mainland Africa, all the results are for plants endemic to Madagascar and the Comoro Islands. While there is a strong correlation between basic number and growth form in the two subgenera of the genus on the African mainland (x = 15 among caulescent species in subgenusStreptocarpella; x = 16 among acaulescent species in subgenusStreptocarpus), the situation appears more complex among Madagascan and Comoro Island species. One notable example of deviation from this correlation is shown byS. papangae, a shrubby caulescent species, with 2n = 32 (x = 16). Polyploidy in the genus appears to be absent on mainland Africa, but is present in Madagascar and the Comoro Islands, ranging from tetraploidy to octoploidy. Evolutionary implications of the cytological observations are considered.
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  • 29
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    Plant systematics and evolution 225 (2000), S. 85-101 
    ISSN: 1615-6110
    Keywords: Elaeagnaceae ; Hippophae ; sea buckthorn ; Systematics ; taxonomy ; genetic variation ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetic diversity has been investigated by the application of molecular markers in, for the first time, all the taxa recognised in recent treatises of the genusHippophae. RAPD (random amplified polymorphic DNA) analyses were conducted with 9 decamer primers, which together yielded 219 polymorphic markers. We found 16 fixed RAPD markers, i.e. markers that either occurred in all plants of a population or were absent from all plants. Several of these markers were useful for analysis of interspecific relationships, whereas others can be considered as taxon-specific markers. Clustering of taxa and populations in our neighbour-joining based dendrogram was in good agreement with some recently suggested taxonomic treatises ofHippophae. Amount and distribution of genetic variability varied considerably between species. Partitioning of molecular variance withinH. rhamnoides supported earlier findings that a considerable part of the total variance resides among subspecies (59.6%) Within-population variability also differed considerably. Percentage polymorphic RAPD loci and Lynch and Milligan within-population gene diversity estimates showed relatively high values for some species close to the geographic centre of origin in Central Asia, e.g.H. tibetana and the putatively hybridogenousH. goniocarpa. Spatial autocorrelation analyses performed on 12 populations ofH. rhamnoides revealed positive autocorrelation of allele frequencies when geographic distances ranged from 0 to 700 km, and no or negative autocorrelation at higher distances. At distances between 700 and 1900 km, we observed deviations from the expected values with strongly negative autocorrelation of allele frequencies. A corresponding relationship between geographic and genetic distances could not be found when the analysis instead was based on one population from each of 8 species.
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  • 30
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    Hydrobiologia 439 (2000), S. 91-101 
    ISSN: 1573-5117
    Keywords: Rotifera ; Bdelloidea ; Korea ; taxonomy ; biogeography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Twenty-five samples from 18 terrestrial and/or freshwater habitats in the eastern part of Korea yielded 38 new records of bdelloid rotifers, 22 of which are new to the Asian fauna. Among these Korean new records, Dissotrocha aculeata reversa Berzins and Habrotrocha plana Milne were recorded outside their type localities for the first time, and Macrotrachela bullata (Murray) was reported only from two countries after its description. Bradyscela granulosa de Koning, Habrotrocha gracilis gracilis Montet, Macrotrachela latior Donner, Philodina duplicalcar (de Koning) and P. rugosa coriacea Bryce are recorded outside Europe for the first time. The taxonomy and distribution of these rare species are discussed.
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  • 31
    ISSN: 1573-5117
    Keywords: taxonomy ; cytogenetic methods ; Cyclops kolensis ; Cyclops strenuus strenuus
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    Notes: Abstract Comparisons of behavior of chromosomes and characteristics of eliminated chromatin during anaphase of chromatin diminution divisions were made of Russian and German populations of Cyclops kolensis and Cyclops strenuus strenuus. Differences in cytogenetic features included timing and amount of eliminated chromatin. Differences were also marked in duration of chromatin diminution, as well as timing and location of eliminated DNA between Russian and German populations of C. strenuus strenuus. In contrast to the German population of C. strenuus, the Russian population of C. strenuus strenuus did not exhibit gonomery.
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  • 32
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    Hydrobiologia 418 (2000), S. 73-80 
    ISSN: 1573-5117
    Keywords: Rotifera ; Bdelloidea ; pictorial key ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We propose a simple, user-friendly key joined to a pictorial key to the bdelloid genera, in the attempt to make bdelloid identification more accessible to non-bdelloid-specialists. The key is mostly based on illustrations rather than on descriptions, and is accompanied by an introduction of the main features readily observable in active bdelloids.
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  • 33
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    Hydrobiologia 418 (2000), S. 169-184 
    ISSN: 1573-5117
    Keywords: ostracods ; upper lip ; taxonomy ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper represents the first study of the morphology of the upper lip (labrum) and hypostome of ostracods using scanning electron microscopy (S.E.M.). There is considerable variation in the upper lip morphology of the 23 species of Cypridoidea (Podocopina) ostracods used in this study. The detail of the upper lip morphology of each species is very distinctive, so that species determination can be made on this feature alone, but it is not useful in diagnosing genera or subfamilies. The hypostome is not readily studied due to the large amounts of dense pseudochaetae (small, setae-like projections) protruding from it and hence is considered not to be a useful taxonomic feature. Several features of the upper lip and mouth region are documented for the first time. Comparisons of the general morphology of the upper lips of Recent ostracods with the upper lip of the fossil ostracod Pattersoncypris micropapillosa Bate, 1972, indicate that there has been very conservative evolution in these features since the Cretaceous.
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  • 34
    ISSN: 1573-5117
    Keywords: new species ; Ryocalanoid copepod ; taxonomy ; benthopelagic ; Sagami Bay
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    Notes: Abstract A new Ryocalanoid copepod, Ryocalanus spinifrons, collected by the MTD net system at a depth of 1400 m from the southwestern part of Sagami Bay, Japan, is described. The new species is morphologically very close to R. infelix Tanaka, 1956 (female unknown) from the Izu region of Sagami Bay. It is distinguished from other species by the presence of 12 long spinules on the ventral inner side of the fifth pedigerous somite, nine setae on the coxal epipodite of the maxillule and nine large robust spinules on the coxal segment of the fourth leg. The row of five robust spines on the paragnath distinguishes R. spinifrons.
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  • 35
    ISSN: 1573-5117
    Keywords: copepodid instars ; Eucyclopinae ; taxonomy ; morphological characters
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    Notes: Abstract Morphological characters useful for taxonomic identification of older copepodid instars of the subfamily Eucyclopinae were studied among 14 species of Eucyclops, Macrocyclops, Ectocyclops, Paracyclops and Tropocyclops known from European Russia. For taxonomic analysis, the following elements of copepodid morphology were chosen: armament and proportion of furcal rami; morphology of swimming legs and reduced 5th and 6th legs; antennule segmentation; and relative body length of copepodid instars in comparison with the female length. Changes in morphology of major copepodid instars of the subfamily Eucyclopinae during ontogenetic development are traced and noticeable differences among five genera and 14 species are described. These differences among major copepodid stages may be important for both taxonomic and ecological analysis. For taxonomy, they provide information on development of sexes and species during maturation. For ecology they allow identification of the specimens at 4–5 copepodid instars in diapause. A key to major copepodid instars of the species from the subfamily Eucyclopinae which are known from limnetic habitats of the European part of Russia is presented.
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  • 36
    ISSN: 1573-5117
    Keywords: morphological variation ; fluctuating asymmetry ; taxonomy ; Copepoda ; Cyclopidae ; Acanthocyclops signifer ; Lake Baikal
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    Notes: Abstract Use of traditional methods for morphological studies only permits the analysis of a small part of the information embodied in morphological structures. Besides comparing populations using the mean values of characters which allows one to estimate their morphological similarity, analysis of variation among individuals within a population can be informative. Variation among individuals consists of factorial and stochastic components. The factorial component is an upper estimate of genetic heterogeneity and thus permits one to evaluate the population's adaptability. The stochastic component (estimated by fluctuating asymmetry, i.e. random deviations from perfect bilateral symmetry), being a measure of developmental stability, is an indicator of a population's fitness. Assessment of measurement error is necessary for assessment of the true value of the stochastic component and for selection of the most informative characters. Such analysis allows one to extract additional information from morphological data in comparison with methods traditionally used on copepods. This approach was applied to an analysis of morphological variation in the study of the Baikalian endemic cyclopoid Acanthocyclops signifer (Mazepova) from three different isolated localities. Characters typically used in studies of taxonomy of this group are considered here. Measurement error was rather high (more than 50% of the stochastic component), which can be explained by technical difficulties of measuring the characters. All populations differ in the mean values of the characters. This shows the taxonomic heterogeneity of this group and reveals the necessity of its taxonomic revision. Populations also differ in the level of stochastic and factorial components of the total variance. The data are interpreted from the point of view of taxonomy and the possible evolution of the group.
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  • 37
    ISSN: 1573-5117
    Keywords: Harpacticoida ; new species ; redescription ; taxonomy ; troglobitics ; trans-Atlantic distribution
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    Notes: Abstract Nitocrellopsis texana n. sp. found in samples collected by SCUBA divers in Honey Creek Cave (Texas, U.S.A.) is described. This species is the first representative of this stygobitic taxon from a Northern American locality. The original description of N. ioneli (Dumont & Decraemer, 1975) is amended and the closely related N. ahaggarensis n. sp. is described from a well near Tamanghasset in the Ahaggar mountains in Algeria. The monophyly of Nitocrellopsis is discussed and its present day distribution is analyzed.
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  • 38
    ISSN: 1573-5117
    Keywords: dinoflagellates ; Prorocentrum ; morphology ; taxonomy ; Mexican Pacific ; red tides
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    Notes: Abstract We surveyed the dinoflagellate genus Prorocentrum Ehrenberg in Mexican Pacific waters, where it is rather common and sometimes causes red tides in coastal areas or shrimp farms. Material collected from Baja California and the Gulf of California was analyzed. Thirteen species were identified, all of them planktonic (although P. mexicanum is also epiphytic). All species are described by light microscopy, and most are also described by scanning electron microscopy; comments on morphology, taxonomy and distribution are made. Red tides were caused by P. dentatum, P. minimum and P. triestinum. Prorocentrum mexicanum and P. minimum were suspected of being toxic. Four species, previously reported in the Gulf of California, were not found. A total of 18 species, including the new records P. dactylum and P. lebourae have been to date reported from the Mexican Pacific.
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  • 39
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    Hydrobiologia 441 (2000), S. 63-71 
    ISSN: 1573-5117
    Keywords: Mongolia ; Eucyclops dumonti ; taxonomy ; zooplankton ; spring fauna
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Eucyclops dumonti sp.nov. is described from a shallow spring-fed lake in Central Mongolia. Data on its morphological variability are given, a comparison with the type population of Eucyclops serrulatus (Fischer, 1853) from St. Petersburg area is made, and its position relative to some closely related congeners is discussed.
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  • 40
    ISSN: 1573-5117
    Keywords: Diaphanosoma dubium ; D. pseudodubium sp.nov. ; morphology ; taxonomy ; geographical distribution
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    Notes: Abstract The poorly known D. dubium Manuilova is redescribed on extensive material from more than 80 populations from the Russian Far East, Central Asia, Mongolia, China, Japan, Vietnam, the Philippines, Thailand, Malaysia, Bangladesh, India and Sri Lanka. Its morphological variability and geographical distribution are analysed and supplemented by notes on biology. The conspecificity of morphologically different distant populations is discussed. In the northern part of its range, D. dubium was long confused with D. brachyurum or D. leuchtenbergianum, and in the south with D. modigliani. It seems that the recent appearance of D. dubium in fish ponds of Uzbekistan and Kazakhstan was an introduction, together with Far Eastern fish. D. pseudodubium sp.nov., close to but markedly different, is described from two lakes in the lower Amur river system. D. dubium, D. pseudodubium, D. tropicum and D. modigliani s. str. form a group of related species, widely distributed in Eastern and Southern Asia.
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  • 41
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    Hydrobiologia 420 (2000), S. 73-90 
    ISSN: 1573-5117
    Keywords: sibling species ; taxonomy ; DNA ; electrophoresis ; allozymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The tools of molecular genetics have enormous potential for clarifying the nature and age of species boundaries in marine organisms. Below I summarize the genetic implications of various species concepts, and review the results of recent molecular genetic analyses of species boundaries in marine microbes, plants, invertebrates and vertebrates. Excessive lumping, rather than excessive splitting, characterizes the current systematic situation in many groups. Morphologically similar species are often quite distinct genetically, suggesting that conservative systematic traditions or morphological stasis may be involved. Some reproductively isolated taxa exhibit only small levels of genetic differentiation, however. In these cases, large population sizes, slow rates of molecular evolution, and relatively recent origins may contribute to the difficulty in finding fixed genetic markers associated with barriers to gene exchange. The extent to which hybridization blurs species boundaries of marine organisms remains a subject of real disagreement in some groups (e.g. corals). The ages of recently diverged species are largely unknown; many appear to be older than 3 million years, but snails and fishes provide several examples of more recent divergences. Increasingly sophisticated genetic analyses make it easier to distinguish allopatric taxa, but criteria for recognition at the species level are highly inconsistent across studies. Future molecular genetic analyses should help to resolve many of these issues, particularly if coupled with other biological and paleontological approaches.
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  • 42
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    Hydrobiologia 424 (2000), S. 101-108 
    ISSN: 1573-5117
    Keywords: Ceratium ; freshwater ; ecology ; morphology ; taxonomy
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    Notes: Abstract A new taxon of Ceratium is described from Lake Doïrani, Greece. It is proposed as a new species and named Ceratium monoceras. It differs morphologically from known species of Ceratium by having only one horn, the apical horn. Accordingly, the vegetative cells form cysts that have only one spine. Details of its ecology and occurence are given.
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  • 43
    ISSN: 1573-5117
    Keywords: taxonomy ; marine nematodes ; Cervonema ; Laimella ; the Strait of Magellan ; Chile
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    Notes: Abstract Five species of Cervonema and four species of Laimella are described from the Strait of Magellan and the Beagle Channel, Chile, six species of which are new to science. Cervonema chilensisn. sp. and Cervonema hermanin. sp. are separated from other known species of Cervonema by a short cervical region (less than one head diameter from the front end to the anterior border of the amphids). Cervonema chilensisn. sp. is characterised by a tail length of 5 anal diameters with posterior half filiform; Cervonema hermani n. sp. is characterised by a tail length of 6–9 anal diameter and posterior part (75%) cylindrical. Cervonema shiaen. sp. is characterised by the cephalic seta 4 μm long, amphids 9–10 μm in diameter; spicules 16 μm long and 0.8–0.9 abd; tail 4.7–5.4 anal diameter and 50% posterior part filiform; 4–5 minute precloacal supplements. Laimella subterminatan. sp. is characterised by the subterminal position of the buccal cavity which separates it from the other species of the genus. Laimella annaen. sp. is characterised by the head diameter 9–11 μm, cephalic setae and external labial setae 9 + 5 μm long, respectively, amphids 7 μm in diameter; spicules 28–30 μm long; tail 14–17 anal diameter and posterior part (75%) filiform; 5 precloacal supplements. Laimella sandraen. sp. is very close to Laimella annaen.sp. in having similar cephalic sensilla, amphids and spicules. Laimella sandraen. sp., however, can be separated from L.annaen. sp. by the shape of head and the structure of sperm cells, the total body length and the cylindrical part of tail. Cervonema papillatum Jensen, 1988, C. tenuicauda (Stekhoven, 1950) and L. longicauda Cobb, 1920 are found in this area as well. The key of all known species of Cervonemaand Laimellais presented.
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  • 44
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    Hydrobiologia 428 (2000), S. 61-66 
    ISSN: 1573-5117
    Keywords: parasitic Copepoda ; taxonomy ; new species ; grey mullet
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    Topics: Biology
    Notes: Abstract A new Nipergasilus species is described from the gills of the grey mullet Valamugil cunnesius from several localities in India and Pakistan. The new species is closely related to Nipergasilus bora (Yamaguti, 1939) which is also recorded here on three species of grey mullet. The genus Nipergasilus is redefined in order to accommodate the second species.
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  • 45
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    Hydrobiologia 428 (2000), S. 1-59 
    ISSN: 1573-5117
    Keywords: Clitellata ; Oligochaeta ; Lumbriculidae ; Rhynchelmis ; taxonomy
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    Topics: Biology
    Notes: Abstract The Nearctic species of Rhynchelmis (Lumbriculidae) are distinguished from the Palearctic group Rhynchelmis s. str. by longitudinal muscle bands that do not curl inwards. Six new species from western North America support the existence of two major groupings within the Nearctic fauna. Species in Group 1 are distinguished from other Rhynchelmis by large penial bulbs and multiple spermathecal diverticula. Within Group 1, Rhynchelmis yakimorum n. sp., Rhynchelmis monsserratus n. sp., Rhynchelmis gustafsoni n. sp. and Rhynchelmis utahensis n. sp. differ from the related Rhynchelmis (=Sutroa) rostrata in having short penes and spermathecae with 2 short, lobed diverticula. R. monsserratus is distinguished by a single, median spermatheca, R. gustafsoni has closely appressed, median spermathecae and atria, and R. utahensis differs in structural details of spermathecae and male pores. Rhynchelmis gilensis n. sp. has a single, median spermatheca with unbranched diverticula and distinctive nephridia. Redescription of material from the type localities of both Sutroa alpestris and R. rostrata supports their combination. Group 2, corresponding in part to Rhynchelmoides, is distinguished from Group 1 mostly by characters that are inconsistent or appear plesiomorphic. Within Group 2, Rhynchelmis saxosa n. sp. closely resembles Rhynchelmis alaskana, except for the absence of lateral blood vessels in posterior segments and distribution of prostates. Rhynchelmis elrodi and Rhynchelmis glandula consistently differ in presence of ventral glands and have different distributions, so their supposed synonymy is rejected.
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  • 46
    ISSN: 1573-5117
    Keywords: marine nematodes ; Epsilonematidae ; Metepsilonema ; taxonomy ; key to species
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    Notes: Abstract Four new species of Metepsilonema are described from sublittoral stations from the Channel and are mainly characterized: M. volutum sp.nov. by the large body size for the genus up to 460 μm, 118–121 well overlapping annuli and wide multispiral amphids; M. amphidoxum sp.nov. by 127–133 shortly overlapping annuli and sexual dimorphism in amphid size; M. comptum sp.nov. by 133–140 non-overlapping annuli, anteriormost annuli provided with a wide lumen and borders ornamented with ridges and M. corrugatum sp.nov. by 108–111 overlapping annuli provided with ridges). Additional information is provided for M. callosum together with a discussion on intraspecific variability. A new species of Metepsilonema spec. based on females only, is described but remain unnamed. M. comptum sp.nov. and M. corrugatum sp.nov. are also occurring in the Mediterranean Sea. A polytomous key to species level is presented.
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  • 47
    ISSN: 1573-5117
    Keywords: China ; freshwater ; Nematoda ; new species ; Parodontophora ; taxonomy
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    Notes: Abstract Parodontophora limnophila sp. nov. is described from Poyang Lake, the largest freshwater lake of China. It is characterized by having an amphid with its posterior end close to the base of the stoma, relatively short cephalic setae, opisthocephalic setae arranged as two subdorsal groups of three longitudinally arranged setae and two single subventral setae, excretory pore at the level of the anterior part of the stoma and renette gland 34–47% of the oesophageal length. To date, the new species is the only Parodontophora species found in freshwater habitats.
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  • 48
    ISSN: 1573-5117
    Keywords: Harpacticoida ; ground water ; interstitial ; taxonomy ; Slovenia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genus Morariopsishas a disjunct distribution. It has been found in south-eastern Europe and in the Baikal region in Russia. In Europe two species are known, both from the Dinaric region. They have been found in three caves only, but always in puddles filled with percolating water. This indicates that they inhabit an unsaturated karstic environment. A third species, Morariopsis dumontin.sp has now been found, in the same type of habitat, on several dates, in a small cave in central Slovenia. Males were recorded for the first time in this genus. The new species is related to Morariospsis kieferiPetkovski, 1959 from Dalmatia. The main differences are in the ornamentation of the furca and of the abdominal segments. P5 and particularly endopodite of P4 in males suggest a close relation between Morariaand Morariopsis.
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  • 49
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    Hydrobiologia 437 (2000), S. 235-239 
    ISSN: 1573-5117
    Keywords: Harpacticoida ; ground water ; interstitial ; taxonomy ; Slovenia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Parastenocaris andreji n. sp. was found in ground water in a northwestern part of Slovenia (southern part of Central Europe). Two adult females of the new species were filtered out of 20 000 l of water during examination of an aquifer for water supply. The bore well was 10 m deep. The aquifer is fed by rainwater and probably only occasionally from a nearby alpine river Sava. The new species differs markedly from other known species of the genus by shape and armature of furcal rami, very long and slim maxillae and some characters on endopodites P2–P5. The closest related species are probably Parastenocaris nolliKiefer, 1938 with subspecies P. nolli alpinaKiefer, 1960, P. gertrudae Kiefer, 1968 and P. austriacaKiefer, 1976.
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  • 50
    ISSN: 1573-6857
    Keywords: Drosophila melanogaster ; Drosophila mauritiana ; Drosophila simulans ; sexual isolation ; species-specific sexual discrimination
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    Topics: Biology
    Notes: Abstract The sexual isolation among the related species Drosophila melanogaster, D. simulans and D. mauritiana is asymmetrical. While D. mauritiana males mate well with both D. melanogaster and D. simulans females, females of D. mauritiana discriminate strongly against males of these two species. Similarly, D. simulans males mate with D. melanogaster females but the reciprocal cross is difficult. Interspecific crosses between several populations of the three species were performed to determine if (i) males and females of the same species share a common sexual isolation genetic system, and (ii) males (or females) use the same genetic system to discriminate against females (or males) of the other two species. Results indicate that although differences in male and female isolation depend on the populations tested, the isolation behaviour between a pair of species is highly correlated despite the variations. However, the rank order of the isolation level along the populations was not correlated in both sexes, which suggests that different genes act in male and female sexual isolation. Neither for males nor for females, the isolation behaviour of one species was paralleled in the other two species, which indicates that the genetic systems involved in this trait are species-pair specific. The implications of these results are discussed.
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  • 51
    ISSN: 1573-6857
    Keywords: aging ; Drosophila melanogaster ; middle class neighborhood ; mortality ; mutation accumulation ; senescence
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    Topics: Biology
    Notes: Abstract Theories for the evolution of aging rest on the assumption that at least some deleterious mutations have effects that are limited to certain ages. Many mutation accumulation studies have tried to measure the number and magnitude of deleterious mutations, but few studies have tried to determine the extent to which the effects of mutations are limited to particular ages. Here we estimate the age-specific effect of deleterious mutations on mortality rate in an outbred population of the fruit fly, Drosophila melanogaster. We used the ‘middle class neighborhood’ approach to accumulation mutations in populations of flies that had recently been obtained from the wild. There are mutations that increase mortality rates, but whose effects are limited to specific ages. The age-specificity of mutational effects differs between the sexes, between virgin and mated flies, and over time. After 10 and 20 generations of mutation accumulation, there were clear age-specific effects of mutations. After 30 generations, however, the degree of age-specificity decreased. In addition, mutation accumulation led to a steady increase in larval mortality and a small but significant increase in the sex ratio of eclosing flies. We discuss the implications of these results for models of aging, and suggest approaches that future studies should take to obtain accurate information on the age-specificity of novel mutations.
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  • 52
    ISSN: 1573-6849
    Keywords: centromere ; Drosophila melanogaster ; heterochromatin ; satellite DNA
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  • 53
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    World journal of microbiology and biotechnology 16 (2000), S. 869-880 
    ISSN: 1573-0972
    Keywords: Biotechnology ; ecology ; fungi ; nomenclature ; synopsis ; taxonomy ; thermophilic ; thermotolerant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract In applied research work dealing with heat-tolerant fungi, currently classified into two groups: namely thermotolerants and thermophiles, information on levels of thermotolerance is generally scant. Cited binomials are often referred to as representatives of thermophilic taxa. The present contribution attempts to specify proper heat-tolerance levels of species cited in biotechnological papers of academic and applied research types published in the last four decades. This assessment integrates relevant available information concerning well defined thermotolerant taxa. Distinction between both groups of heat-tolerant fungi is a mean to optimize investigations of temperature-dependent physiological processes. The nomenclatural status of the binomials retrieved was also re-appraised following the International Code of Botanical Nomenclature. Articles of the code govern the legal validity of fungal names. The goal is to deter `ghost names' that have no status of any kind. Their use in the literature is not only a source of confusion but also hinders the preparation of sound reviews and reference documents. The intention was also to detect names which do not fulfill all criteria for a valid legal publication. Their status could then be validated if the taxonomic position of the fungus justifies this procedure. The taxonomic status of these thermotolerants was also re-examined following present-day knowledge of their respective genera. Integration of warranted taxonomic decisions in the literature of applied research is crucial. These decisions consider the status of a fungus as a valid species (proposed synonymies) or the nature of its generic affinities (name change). Strict application of these decisions severly reduces levels of heterogeneity regarding names used for the same organism. It also clarifies its generic affinities with other thermotolerant fungi. The present note is not an exhaustive assessment on the nomenclatural and taxonomic positions of known thermotolerant fungi, an ecological group for which a global document remains to be produced. It only deals with those taxa most commonly cited in the literature examined. Over 130 fungi are here considered. The group manifests a diversity of taxonomic characters since it includes members of the following systematic groupings: Oomycetes, Zygomycetes, Ascomycetes, anamorphic fungi and Holobasidiomycetes. Few new taxonomic synonyms and invalid binomials are introduced in the present contribution. The former concern the following taxa: Gilmaniella thermophila, Mucor thermoaerospora, Sporotrichum lignicola and Zalerion thermophylii. Three binomials proved to have no taxonomic status of any sort: Acremonium cellulophilum, Nodulisporium microsporum and N. thermoroseum.
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  • 54
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    Educational studies in mathematics 43 (2000), S. 191-221 
    ISSN: 1573-0816
    Keywords: analog objects ; children's informal knowledge ; conceptual mapping ; fair shares ; partitive quotient fraction construct ; partitioning tasks ; partitioning strategies ; quantification ; taxonomy ; teaching interventions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Taxonomies for classifying children's partitioning strategies have generally focused on the contexts in which the strategies occur and whether the strategies generate fair shares. Therefore, the overall aim of this study was to increase our knowledge about young children's partitioning strategies by setting out not only to identify new partitioning strategies but also to develop a taxonomy for classifying young children's partitioning strategies in terms of their ability to facilitate the abstraction of the partitive quotient fraction construct from the concrete activity of partitioning objects and/or sets of objects. Clinical interviews were conducted with twelve purposely-selected Year Three students. Each student was presented with a unique set of realistic partitioning tasks. The paper concludes with a taxonomy for: (i) qualitatively evaluating a child's progress towards the abstraction of the partitive quotient fraction construct, and (ii) planning and implementing teaching interventions commensurate with the child's level of progress towards the abstraction of the partitive quotient fraction construct. This taxonomy provides researchers and teachers with means of better utilising children's informal partitioning strategies as the foundation upon which to further develop their understandings of the partitive quotient fraction construct.
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  • 55
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    Antonie van Leeuwenhoek 77 (2000), S. 37-42 
    ISSN: 1572-9699
    Keywords: new yeast species ; Pichia sporocuriosa ; taxonomy
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    Topics: Biology
    Notes: Abstract A strain of a hitherto undescribed yeast species with a unique ascospore morphology was isolated from rambutan (Nephelium lappaceum). A description of the new species, Pichia sporocuriosa, is given.
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  • 56
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    Antonie van Leeuwenhoek 78 (2000), S. 123-127 
    ISSN: 1572-9699
    Keywords: Bacillus subtilis ; gyrA ; phylogeny ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Partial gyrA sequences were determined for twelve strains belonging to Bacillus amyloliquefaciens, B. atrophaeus, B. licheniformis, B. mojavensis,B. subtilis subsp. subtilis, B. subtilissubsp. spizizenii and B. vallismortis. The average nucleotide and translated amino acid similarities for the seven type strains were 83.7 and 95.1%, respectively, whereas the corresponding value for the 16S rRNA sequences was 99.1%. All of the type strains were sharply separated; the closest relationship was found between B. atrophaeus and B. mojavensis which shared a nucleotide similarity of 95.8%. Phylogenetic trees were inferred from gyrA nucleotide sequences using the neighbor-joining, Fitch–Margoliash and maximum parsimony algorithms. The test strains were divided into four groups, which generally reflected results previously reported in restriction digest and DNA-DNA hybridization studies. It is concluded from the comparative sequence analysis that the gyrA sequences provide a firm framework for the rapid and accurate classification and identification of Bacillus subtilis and related taxa.
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  • 57
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    Antonie van Leeuwenhoek 77 (2000), S. 71-81 
    ISSN: 1572-9699
    Keywords: DNA heterogeneity ; genome comparison ; Geotrichum ; taxonomy ; yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nutritional physiology and the growth rate of thirty-four strains representing species of Geotrichum without known teleomorph states were examined. From twenty-seven strains the mol% G+C were calculated from the DNA melting curves. The first derivatives of the melting curves of seven strains, including the type strain of Geotrichum clavatum, demonstrated the presence of two peaks, 12% away from each other; the remaining strains showed only a single broad peak. DNA homology values among strains of the former group were high, indicating their conspecificity. The strains of the latter group could be subdivided into six DNA homology groups, four of which could be identified with recognized species and two may represent novel taxa. A combined key of Geotrichum and its teleomorph states Galactomyces and Dipodascus is presented.
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  • 58
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    Experimental and applied acarology 24 (2000), S. 213-225 
    ISSN: 1572-9702
    Keywords: Psoroptes ; taxonomy ; species differentiation ; phenotype ; genotype
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The biosystematic status of mite species belonging to the genus Psoroptes Gervais, 1841 is difficult to determine by phenotypic methods and has been subject to taxonomic revisions and ongoing debate. At present, the existence of five species, P. cuniculi (Delafond, 1859), P. ovis (Hering, 1838), P. equi (Hering, 1838), P. cervinus Ward, 1915 and P. natalensis Hirst, 1919, is generally accepted. This classification is based mainly on the host species, the localization of the mites on their hosts and morphological characters of male mites. However, a critical review of the literature indicates that the features used to discriminate between the five species are not unequivocal: (a) the localization of mite populations on host animals is not completely strict, (b) the lengths of the outer opisthosomal setae of male mites, which are the main morphological features used for species discrimination, overlap between the five postulated species, and (c) host specificity cannot be deduced from results of transfer experiments. Rather, conspecificity of the members of the genus Psoroptes has to be presumed which is supported by molecular genetic analyses. On these grounds and on rules of priority P. cervinus Ward, 1915, P. cuniculi (Delafond, 1859), P. natalensis Hirst, 1919 and P. ovis (Hering, 1838) are seen as synonyms of P. equi (Hering, 1838).
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  • 59
    ISSN: 1572-9699
    Keywords: Basidiomycetous yeasts ; Kondoa aeria sp. nov. ; ribosomal DNA sequencing ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genus Kondoa Y. Yamada, Nakagawa & Banno was erected to accommodate a single taxon, K. malvinella (Fell & Hunter) Y. Yamada, Nakagawa & Banno, which was transferred from the teliospore-forming genus Rhodosporidium Banno based on pronounced differences in the 5S and 26S ribosomal RNA (rRNA) nucleotide sequences to R. toruloides Banno. In contrast with the original description, reinvestigation of K. malvinella revealed the formation of transversely septate (auricularioid) basidia that did not arise on teliospores, but formed directly on the dikaryotic mycelium. The four-celled basidia developed sterigmata on which forcibly discharged asymmetric basidiospores (ballistospores) were produced. Additionally, a new taxon emerged from the study of recent isolates, for which the name K. aeria sp. nov. is proposed. This new species produced two-celled auricularioid basidia on hyphae with incomplete clamp connections. Ballistospores arose on the basidia at the tip of sterigmata and, after ejection, germinated by budding. These observations led us to present an emended diagnosis for the genus Kondoa. Analysis of the sequence data from the D1/D2 region of the 26S rRNA gene showed a very close resemblance between K. aeria and K. malvinella in a cluster that also contained several Bensingtonia species. Taxa in this cluster share specific physiological traits and produce characteristic pinkish-cream to mauve colonies; in contrast, formation of ballistoconidia is only observed in the Bensingtonia species. Sequence data supported placement of K. malvinella and K. aeria in the `Agaricostilbum clade' of the Urediniomycetes.
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  • 60
    ISSN: 1573-5109
    Keywords: cultivated plants ; databases ; herbarium ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The herbarium collection of the N.I. Vavilov Institute of Plant Industry (WIR) contains specimens of cultivated plants, their wild relatives and weedy plants and provides ample opportunities for research. It is a unique special herbarium collection and one of those rare collections having a card index (catalog). For the catalog to be functional, it should reflect the current changes in the taxa names. Only a computerized card file may meet this requirement. The creation of a database for VIR's herbarium was launched in 1995. VIR is carrying out a range of work necessary for providing a wider access to its herbarium and related information for the international scientific community.
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  • 61
    ISSN: 1573-5109
    Keywords: evolution ; genetic resources ; RAPDs ; seed protein electrophoresis ; taxonomy ; Vicia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The genetic diversity of 58 wild and weedy populations representing taxa within the V. sativa aggregate from the former USSR, 4 cultivars of V. sativa, 2 accessions of V. cordata and 3 accessions of V. macrocarpa from Mediterranean countries were analysed using randomly amplified DNA fragments (RAPDs) and seed protein electrophoresis (SDS-PAGE). Interspecific variation between taxa in the V. sativa aggregate could readily be detected using both techniques. RAPDs and seed protein patterns were found to be an effective means of identifying accessions that cannot be identified clearly by morphological criteria alone. RAPD and seed protein analysis revealed a clear relationship between observed genetic variation of populations and their geographical distribution. Populations from each region had their own gene pools. Geographical variation was detected in V. segetalis. The degree of genetic divergence between local populations was usually related to proximity. In several locations where wild and weedy populations of different V. sativa agg. taxa grow sympatrically, intermediate forms could be detected at the DNA and protein levels. Both RAPD and seed protein analysis support the view that the V. sativa aggregate consists of 8 taxa warranting recognition at the species level. Several species in this aggregate are evolving intra-specific groups which can readily be detected at the molecular level.
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  • 62
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    Hydrobiologia 417 (2000), S. 1-10 
    ISSN: 1573-5117
    Keywords: taxonomy ; copepods ; Einsle ; chromatin diminution ; enzyme electrophoresis ; Cyclops
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  • 63
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    Hydrobiologia 421 (2000), S. 77-90 
    ISSN: 1573-5117
    Keywords: Tobrilidae ; new record ; Nematoda ; taxonomy ; China
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Eutobrilus annetteae Joubert & Heyns, 1979 with its male reported for the first time, Semitobrilus pellucidus (Bastian, 1865) Tsalolichin, 1983, and Epitobrilus allophysis(Steiner, 1919) Tsalolichin, 1996 are described from the Li River at Guiling, China. The male of Eutobrilus annetteae is characterized by lots of crystalloids inside body, almost straight spicules about one anal body diameter long and seven equally sized supplements. Semitobrilus pellucidus from Guiling shows large variation in body width, position of amphids, form of buccal cavity, distance between denticles, direction of vagina, arrangement of oocytes, and shape of eggs. It is different from other populations in its shorter cephalic setae, less than 60% of head width, in its shorter tail and smaller c′ value. In males, there are 6–9 supplements, reduced and irregulary spaced. Epitobrilus allophysisis characterized by its labial setae longer than 50% of head width, small, posteriorly located ovoid amphid, single egg occupying whole space of uterus and blunt tail tip.
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  • 64
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    Hydrobiologia 421 (2000), S. 165-178 
    ISSN: 1573-5117
    Keywords: Kurzia ; Crustacea ; Anomopoda ; Chydoridae ; taxonomy ; distribution ; Cladocera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genus Kurzia is divided into two subgenera: Kurzia s. str. and Rostrokurzia n. subg. Subgenus Kurzia includes Kurzia (K.) latissima Kurz, 1874, with a palearctic -, Kurzia (K.) polyspina n. sp. with a neotropic - , and Kurzia (K.) cf. media (Birge, 1879) with a nearctic distribution. Rostrokurzia includes Kurzia (R.) longirostris Daday, 1898 (pantropical distribution), and Kurzia (R.) brevilabris Rajapaksa & Fernando, 1986, from subtropical and tropical Asia. Kurzia latissima Kurz, 1874, from Central Europe is redescribed in detail.
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  • 65
    ISSN: 1573-5117
    Keywords: taxonomy ; marine nematodes ; Sabatieria ; Metacomesoma ; Paramonhystera ; Siphonolaimus ; the Strait of Magellan ; Chile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Six species of Monhysteroida are described from the Strait of Magellan and the Beagle Channel, Chile. Three species of which, Sabatieria heipi n. sp., Paramonhystera geraerti n. sp. and Siphonolaimus smetti n. sp., are new to science. Sabatieria heipi n. sp. is characterised by a body length of 1529–1934 μm, cuticle punctuations with lateral differentiation; cephalic setae 5 μm long, amphids spiral with 4.0–4.2 turns, 10–11 μm in diameter; spicules 76 μm (2.1 anal body diameter), with a 6 μm projection in the ventral distal extremity, 11 minute precloacal supplements; tail 3.7–4.7 anal body diameter (abd) long with enlarged tip. Paramonhystera geraerti n. sp. is characterised by a body size of 705–767 μm; head diameter 12 μm, the cephalic setae 6 μm; amphids circular, 9–10 μm in diameter; spicules slender 108–116 μm (5.6 abd) long, 5 precloacal supplements; and tail 4.0–5.2 abd. Siphonolaimus smetti n. sp. is characterised by the long spear (40–45 μm), head diameter 11–12 μm, amphids circular, 12–13 μm in diameter or 50–57% of corresponding body diameter; the spicules 55 μm and 1.5 abd; tail conical, 2.8 abd (males) and 4.0 abd (females) long. Three other species, i.e. Metacomesoma cyatholaimoides Wieser, 1954, Paramonhystera biforma Wieser, 1956 and P. megacephala (Steiner, 1916) are redescribed. A key of all known species of Paramonhystera is proposed.
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  • 66
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    Hydrobiologia 429 (2000), S. 115-131 
    ISSN: 1573-5117
    Keywords: Mesocyclops mariae n.sp. ; Mesocyclops shenzhenensis n. sp. ; Guangxi ; Guangdong ; China ; taxonomy ; distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two new Mesocyclops species, M. mariae n. sp. and M. shenzhenensisn. sp., are described from southern China, the former species from Guangxi province, the latter from Guangdong province. Both species have setules on the medial margin of the caudal rami. Compared with each other, there are some conspicuous differences, such as the spinule pattern of the antenna basipodite, the structure of receptaculum seminis, the armature of coxopodite and basipodite of P4 and the armature of the caudal rami. The paper also compares the two new species with their supposedly closest relatives, M. pseudospinosus Dussart & Fernando, 1988, M. leuckarti(Claus, 1857) and M. pehpeiensisHu, 1943. In addition, other species of Mesocyclops in China are discussed and a key to 10 Chinese species of Mesocyclops is provided.
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  • 67
    ISSN: 1573-5117
    Keywords: acid ; taxonomy ; protists ; ciliate ; flagellate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The occurrence and some important taxonomic problems of heterotrophic protists from extremely acidic (pH ≤3) environments are briefly discussed. Almost all information on the occurrence of heterotrophic protists from extremely acidic environments is restricted to acid mine drainage (AMD) or streams influenced by AMD. Most of the information is provided for ciliates. Very little information is available on the occurrence of flagellates, rhizopods and heliozoa in this environment. Within the ciliates Urotricha, Vorticella and Oxytricha dominate in acidic mining lakes. Actinophrys sp. is the most important heliozoan in these environments. There are many taxonomic problems which are not solved so far. Live observations and taxonomic methods adapted to the extreme chemical matrix are necessary for correct identification.
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  • 68
    ISSN: 1573-5117
    Keywords: Aphanizomenon ; Cyanobacteria ; 16S rRNA ; morphology ; sequences ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The taxonomy of Aphanizomenon flos-aquae strain NH-5, a producer of cyanotoxins, was re-evaluated by comparison with six other Aphanizomenon strains using morphological characteristics and 16S rRNA gene sequences. Strain NH-5 was concluded to be improperly identified as Aph. flos-aquae based upon (1) lack of bundle formation in the trichomes, (2) location of akinetes next to heterocytes, (3) lower similarities (less than 97.5%) in the 16S rRNA gene sequences relative to Aph. flos-aquae strains, and (4) comparison within a phylogenetic tree constructed from 16S rRNA gene sequences. The Aphanizomenon strains investigated in this study are classified to four morphological groups as described by the classical taxonomy of Komárek & Kovácik (1989). This classification was supported from the phylogenetic results of 16S rRNA gene sequences. This study also discusses the generic boundaries between Aphanizomenon and Anabaena.
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  • 69
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    Hydrobiologia 438 (2000), S. 107-116 
    ISSN: 1573-5117
    Keywords: Cyanophyta/Cyanobacteria ; Aphanizomenon ; Anabaena ; taxonomy ; morphology of trichomes ; heterocytes and akinetes ; Slovakia ; Austria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Morphological variation of trichomes, heterocytes and akinetes in four species classified into the nostocalean genera Aphanizomenon Morren ex Bornet et Flahault or Anabaena Bory (Cyanophyta/Cyanobacteria) was studied from natural samples by LM and illustrated by drawings and micrographs. All investigated species, Aphanizomenon gracile (Lemmerm.) Lemmerm., A. aphanizomenoides (Forti) Komárek et Horecká, Anabaena bergii Ostenfeld, A. minderi Huber-Pestalozzi, occur in the plankton as solitary trichomes, similar to many representatives of the genus Anabaena. Main generic diagnostic characters of Aphanizomenon and Anabaena are discussed.
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  • 70
    ISSN: 1573-5117
    Keywords: Anabaena ; cyanobacteria ; identification ; morphology ; planktic ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fifty (50) strains of planktic species of Anabaena (cyanobacteria), including collections from Japan and China and from different culture collections, were induced to form akinetes at low temperature (15 °C). Their morphologies were then observed and described. Fourty seven strains successfully formed akinetes and these were classified into 20 species comprising seven with straight trichomes and 13 with coiled trichomes. Three strains, which did not form akinetes, were separated into two taxonomic groups, but could not be identified to any described species. In addition, a key to the planktic species of Anabaena described in the study is presented.
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  • 71
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    Hydrobiologia 433 (2000), S. 137-143 
    ISSN: 1573-5117
    Keywords: Cyanidium caldarium ; Cyanidioschyzon merolae ; Galdieria sulphuraria ; taxonomy ; acidophily
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ecophysiological, cytomorphological, biochemical and molecular data presently available for the acidophilic red algal species Cyanidium caldarium, Cyanidioschyzon merolae and Galdieria sulphuraria are summarised. The taxonomic position of the three genera is discussed and emendements to the generic diagnosis are presented.
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  • 72
    ISSN: 1573-5117
    Keywords: Cyanidium caldarium ; Cyanidioschyzon merolae ; Galdieria sulphuraria ; rbcL ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyanidium caldarium, Cyanidioschyzon merolae and Galdieria sulphuraria are three unicellular algae characteristic, of acid thermal environments. Recently, on the basis of morphological characters, three new species of Galdieria (G. partita, G. daedala, G. maxima ) isolated from acid-thermal springs in Russia have been instituted. A selected region of rbcL and the sequence of the intergenic spacer between the rbcL and rbcS have been amplified and sequenced from different Galdieria species and strains, in order to define molecular relationship among these interesting algae. The obtained cladogram shows that Cyanidium caldarium and Cyanidioschyzon merolae form a sister group which, in turn, is in a sister group relationship with Galdieria. This last genus is divided in two clades, one of which includes G. sulphuraria accessions from Naples (Italy), California, and Yellowstone and the other one includes G. sulphuraria accessions from Java (Indonesia) and from the Russian species. These results support the status of the genus Galdieria and suggest that G. daedala, G. maxima and G. partita are three very similar strains of G. sulphuraria; the rbcL variation within Galdieria accessions has a pattern which is broadly connected to the geographial distribution. The data obtained from the intergenic rbcL-rbcS spacer partly confirm those from the rbcL analysis.
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  • 73
    ISSN: 1573-5117
    Keywords: Chydoridae ; Anomopoda ; taxonomy ; Karualona ; trunk limbs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The species group of Alona karua is raised to generic rank and named Karualona. The genus is defined on the basis of a number of characters of the body and its appendages. Tentative new microcharacters are introduced, related to the type and length of selected setae of P1, P2, P3 and P4. Two new species are described, one from the island of Socotra and one from Mexico. A key to the five currently recognized species is given.
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    Hydrobiologia 435 (2000), S. 43-59 
    ISSN: 1573-5117
    Keywords: Nematoda ; Coninckiidae ; Comesomatidae ; White Sea ; taxonomy ; descriptions
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    Topics: Biology
    Notes: Abstract Ten new and known species of the genera Coninckia, Cervonema, Laimella and Sabatieria are described from the White Sea. Coninckia macroseta sp. n. resembles C. seta Wieser et Hopper, 1967 (Florida coast of U.S.A.) in shape of the amphid and other characters, but differs from the latter by greater body length (2399 μm versus 1300–1400 μm) and by the a-index (83 versus and a 57–58). Cervonema proximamphidum sp. n. differs from all other species of Cervonema by the shape of posterior widening of the pharynx (except for C. allometricum Wieser, 1954 whose original description is too brief). The pharynx of the new species forms posteriorly a conical widening with vague radial striation, whereas the pharynx of other Cervonema species presents posteriorly an oval or elongate thickening with wavy contour and distinct muscular transversal striation. The other diagnostic characters of Cervonema proximamphidum sp. n. are close position of the amphid to the anterior end (distance from the anterior end to the amphid 6–7.5 μm), longer outer labial and cephalic setae (5–5.5 μm), relatively longer and slender body (respectively, 1423–1563 μm and a=30.9–41.1). Specimens Cervonema minutus Muthumbi, Soetaert et Vincx, 1997 largely agree with the original description of Muthumbi et al. (1997) based on the nematodes sampled in the Indian Ocean deep sea; only cephalic setae length (2.7–3.5 versus 2 μm) differ. The White Sea specimens Laimella filipjevi coincide well with the description of Jensen (1979) made on nematodes from the western Baltic Sea, except slight difference in body length (1564–1837 μm versus 1086–1152 μm). Sabatieria kolaensis (Ssaweljev, 1912) is redescribed and restored as valid species. Sabatieria kolaensis was assigned by Platt (1985) to the list of dubious species because of very brief original description lacking some important details. Sabatieria kolaensis belongs to the S. praedatrix species group and is characterized by the greatest number of preanal supplements (31–40). Sabatieria lawsi Platt, 1983 was previously known from the only Antarctic Peninsula shelf; the single White Sea male specimen corresponds well to the original diagnosis of Platt (1983). Sabatieria lawsi is considered to be very close or near identical to S. praedatrix de Man, 1907. The species Sabatieria longispinosa Lorenzen, 1972, S. ornata (Ditlevsen, 1918), S. pulchra (G. Schneider, 1906) and S. strigosa Lorenzen, 1972 are also described and discussed.
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    Human evolution 15 (2000), S. 63-74 
    ISSN: 1824-310X
    Keywords: comparative anatomy ; taxonomy ; species ; Homo erectus ; Homo heidelbergensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Patterns of human evolution in the Middle Pleistocene remain poorly understood. There is general consensus that by the onset of this time period, populations ofHomo erectus were dispersed from Africa into Eurasia, including the Far East. In the western part of this range (perhaps in Africa),Homo erectus then produced a daughter lineage exhibiting more advanced characters of the face, braincase and cranial base. How this new species should be defined is currently debated. In my view, fossils from sites such as Bodo and Broken Hill in Africa may be lumped with material from earlier Middle Pleistocene localities in Europe. Such a taxon is appropriately namedHomo heidelbergensis. Whether the hypodigm should be extended to include fossils from China is another question. In any case, this group of hominids is plausibly ancestral to both the specialized Neanderthals of Europe and more modern humans of the later Middle Pleistocene.
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  • 76
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    World journal of microbiology and biotechnology 16 (2000), S. 881-888 
    ISSN: 1573-0972
    Keywords: Biotechnology ; ecology ; fungi ; nomenclature ; status ; synopsis ; taxonomy ; thermophile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The present synopsis reports on taxonomic decisions and name changes introduced in the last decades for a number of thermophilic fungi. Taxa dealt with are those most commonly cited in the literature of fundamental and applied work or concern species having complex taxonomic histories. The definition of a thermophile follows the classificatory scheme elaborated by Cooney & Emerson in 1964. The synopsis provides the latest legal valid names for several thermophiles. Binomials of accepted synonymies are also reported with arguments in favour of these taxonomic decisions. The material of this contribution is a synthetic simplified account of two previous reviews on the taxonomy of thermophilic fungi. The present document aims: (1) to suppress the use of ghost binomials having no status of any kind; (2) to favour the continuous use of the latest legal valid name of a taxon to avoid cases of redundancies by citing binomials of known synonyms. Homogeneity in cited names is a fundamental prerequisite for comparative studies. The synopsis is thus a sound tool for future critical reviews of ecological and of biotechnological interests. The status of over a hundred names are here reviewed. Two additional new synonyms are proposed; these concern Mucor miehei var. minor and Sporotrichum cellulophilum.
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    Development genes and evolution 187 (1979), S. 151-165 
    ISSN: 1432-041X
    Keywords: Oogenesis ; Embryogenesis ; Two-dimensional gels ; Protein synthesis ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Protein synthesis in egg follicles and blastoderm embryos ofDrosophila melanogaster has been studied by means of two-dimensional gel electrophoresis. Up to 400 polypeptide spots have been resolved on autoradiographs. Stage 10 follicles (for stages see King, 1970) were labelled in vitro for 10 to 60 min with35S-methionine and cut with tungsten needles into an anterior fragment containing the nurse cells and a posterior fragment containing the oocyte and follicle cells. The nurse cells were found to synthesize a complex pattern of proteins. At least two proteins were detected only in nurse cells but not in the oocyte even after a one hour labelling period. Nurse cells isolated from stages 9, 10 and 12 follicles were shown to synthesize stage specific patterns of proteins. Several proteins are synthesized in posterior fragments of stage 10 follicles but not in anterior fragments. These proteins are only found in follicle cells. No oocyte specific proteins have been detected. Striking differences between the protein patterns of anterior and posterior fragments persist until the nurse cells degenerate. In mature stage 14 follicles, labelled in vivo, no significant differences in the protein patterns of isolated anterior and posterior fragments could be detected; this may be due to technical limitations. At the blastoderm stage localized synthesis of specific proteins becomes detectable again. When blastoderm embryos, labelled in vivo, are cut with tungsten needles and the cells are isolated from anterior and posterior halves, differences become apparent. The pole cells located at the posterior pole are highly active in protein synthesis and contribute several specific proteins which are found exclusively in the posterior region of the embryo. In this study synthesis of specific proteins could only be demonstrated at those developmental stages which are characterized by the presence of different cell types within the egg chamber, while no differences were detected when stage 14 follicles were cut and anterior and posterior fragments analyzed separately. The differences in the pattern of protein synthesis by pole cells and blastoderm cells indicate that even the earliest stages of determination are reflected by marked changes at the biochemical level.
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    Development genes and evolution 187 (1979), S. 167-177 
    ISSN: 1432-041X
    Keywords: Pyrimidine biosynthesis ; rudimentary mutants ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The X-linkedrudimentary (r) mutants ofDrosophila melanogaster are pyrimidine auxotrophs and require exogenous pyrimidines (Nørby, 1970; Falk, 1976). We have established a set ofrudimentary cell lines that are derived from embryos, homozygous for eitherr 1 orr 36. The enzymatic activities of the pyrimidine synthesizing enzymes were measured in the mutant lines. We have further investigated the nutritional requirements of the mutant cells in vitro by using a pyrimidine free culture medium. Ther 1 cell lines were found to express 3–7%dihydroorotase (DHOase) activity as compared to a wildtype cell line. Reducedaspartate transcarbamylase (ATCase) activity was measured in somer 1 cell lines whereas wildtypecarbamylphosphate synthetase (CPSase) activity is expressed in allr 1 cell lines. Ther 36 cell line expresses wildtype activity ofDHOase andCPSase. ATCase activity was found to be reduced to 10% of the wildtype activity. The mutant cell lines do not proliferate in pyrimidine free minimal medium and cell proliferation is obtained by the addition of crude RNA. Proliferation of ther 1 cells is restored by the supplementation of the minimal medium withdihydroorotate whereas proliferation of ther 36 cells is restored by supplementation with eitherdihydroorotate orcarbamylaspartate. The results demonstrate that therudimentary phenotypesr 1 andr 36 are expressed at the cellular level and that the two mutant cell types behave as cellular pyrimidine auxotrophs in vitro.
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  • 79
    ISSN: 1573-4927
    Keywords: sepiapterin synthase ; variegation ; purple ; Drosophila melanogaster ; pteridine eye pigments ; drosopterin
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A variegated position effect on the autonomous gene, purple, has been studied enzymologically in Drosophila melanogaster. Sepiapterin synthase, the enzyme system associated with pr +, was examined for activity in different developmental stages of the fly. The results indicate that T(Y:2) pr c5, cn/prc4 cn flies (flies in which pr + has been translocated and which exhibit variegation) have a reduced amount of enzyme activity as compared with both Oregon-R and pr 1 flies. This reduction in activity was not found in larval stages, which suggests that the inactivation process probably occurs in late larval or early pupal stages. The phenotype of the variegated adult has white eyes with red-colored spots and patches where drosopterins occur. The phenotype of the fly carrying the translocation is modified by the presence of additional Y chromosomes. This extends the observation from other systems that extra heterochromatin acts to suppress the variegated position effect. The advantages of studying the variegation by measuring enzyme activity, as well as the phenotypic expression, are several; for example, the developmental time at which variegation occurs may be estimated even though drosopterin synthesis is not occurring.
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    Biochemical genetics 17 (1979), S. 1131-1144 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; enzyme polymorphism ; G6PD ; 6PGD ; enzyme activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The electrophoretic variants of G6PD and 6PGD isolated from the Bogota Drosophila melanogaster population were characterized developmentally and biochemically. Changes in in vitro enzyme activity during development were comparable to those found for other dehydrogenases: an increase in the larval and adult stage and a decrease in the pupal stage. During the whole life cycle the “S” enzyme of both loci showed a higher activity than the “F” enzyme. MgCl2 had a stimulating effect on the activity of both enzymes whereas their heat stability was decreased. The allozymes of 6PGD had different Vmax's but were comparable with respect to Km values, pH optimum, and stability at 45 C. the allozymes of G6PD showed different Vmax's and differed in stability at 35 C, but had similar Km values and pH optima. As the difference in stability was probably due to differences in molecular structure of the allozymes, the differences in activity found at high pH and high MgCl2 concentration were most probably due to this difference in stability.
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    Biochemical genetics 17 (1979), S. 1-22 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; esterase 6 ; allozymes ; biochemical properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Biochemical properties of esterase 6 in Drosophila melanogaster were investigated using partially purified preparations from three genotypes, 1/1, 1/2, and 2/2. The molecular weight of the enzyme is estimated to be about 90,000, and treatment with sodium dodecylsulfate cleaves the enzyme into four units with a molecular weight of about 22,000. The activity toward 28 naturally occurring esters was assayed and shown to vary considerably with substrate, the 1/1 preparation having in general higher activity than 1/2 and 2/2, which were very similar. Heat sensitivity, the effect of metal ions, and the effects of the presence or absence of an end product were also studied. The differences demonstrated between allozymes would allow considerable scope, under appropriate conditions, for differential selection to operate between genotypes.
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  • 82
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; phosphoglucomutase ; polymorphism ; enzyme kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Phosphoglucomutase (PGM) of adult stage in Drosophila melanogaster has been characterized by gel filtration, ion-exchange chromatography, and isoelectric focusing. The two common electrophoretic variants, PGMA and PGMB, differ with respect to their kinetic and stability parameters. PGMA is more thermostable than PGMB but shows the same pH optimum, equal dependence on Mg2+, and identical molecular weight. There is no significant kinetic difference between the two allozymes at the optimum pH value, but at pH 6.0 the K m value for glucose-1,6-diphosphate of PGMB is significantly higher than that of PGMA. This difference might explain the observed selective advantage of the Pgm A allele in population studies.
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    Biochemical genetics 17 (1979), S. 97-104 
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; form II RNA polymerase initiation sites ; chromomeres
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The in vitro incorporation of γ-32P-labeled nucleoside triphosphates into RNA by Drosophila melanogaster form II RNA polymerase from template sites which afford protection from the initiation inhibitor, polyriboinosinic acid (poly [I]), is used as a method for enumerating a specific class of transcription initiation sites on D. melanogaster DNA. Such sites number about 4000 per haploid genome for D. melanogaster. This value is in good agreement with the number of functional genetic units in the D. melanogaster genome as determined by classical cytogenetics.
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  • 84
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; Malpighian tubules ; purine transport ; eye color mutants ; riboflavin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Uptakes of guanine into Malpighian tubules of wild-type Drosophila and the eye color mutants white (w), brown (bw), and pink-peach (p p) have been compared. Tubules for each of these mutants are unable to concentrate guanine intracellularly. The transport of xanthine and riboflavin is also deficient in w tubules. The transport of guanosine, adenine, hypoxanthine, and guanosine monophosphate is similar in wild-type and white Malpighian tubules. These data and other information about these mutants make it likely that these pteridine-deficient eye color mutants do not produce pigments because of the inability to transport a pteridine precursor. This view supports the hypothesis that mutants which lack both pteridine and ommochromes do so because precursors to both classes of pigments share a common transport system.
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    Biochemical genetics 17 (1979), S. 149-158 
    ISSN: 1573-4927
    Keywords: xanthommatin synthesis ; scarlet mutants ; Drosophila melanogaster ; temperature-sensitive mutants
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Six new EMS-induced scarlet mutants were selected. Four of these were partially pigmented, with xanthommatin levels ranging from 12% to 45% of normal. In one (st 754ts), pigment production was temperature sensitive; the level of xanthommatin changed from less than 10% of normal at 29 C to more than 70% at 18 C. In all of the new mutants tested, the level of early pupal 3-hydroxykynurenine was as low as low as that in st 1. Thus reduced larval accumulation of this metabolite also appears to be a characteristic feature of scarlet mutants. Temperature-pulse and temperature-shift experiments were carried out with st 754ts to determine the temperature-sensitive period for the scarlet gene during development. The major sensitive period commenced prior to the onset of pigmentation and was over before adult emergence. Thus the initiation of xanthommatin synthesis is not brought about by the activation of the scarlet gene. In similar experiments carried out with a temperature-sensitive white mutant (w bl), a similar temperature-sensitive period was obtained.
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  • 86
    ISSN: 1573-4927
    Keywords: Drosophila melanogaster ; biopterin synthesis ; oxidation of dihydropterins
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An enzyme which has been named “biopterin synthase” has been discovered in Drosophila melanogaster. This enzyme, which has been purified 200-fold from extracts of Drosophila, catalyzes the conversion of sepiapterin to dihydrobiopterin, or oxidized sepiapterin to biopterin. The K m values for the two substrates are 63 µm for sepiapterin and 10 µm for oxidized sepiapterin. NADPH is required in this enzymatic reaction. An analysis of enzyme activity during development in Drosophila indicates a correlation between enzyme activity and biopterin content at various development stages. Another enzyme, called “dihydropterin oxidase,” was also discovered and partially purified. This enzyme catalyzes the oxidation of dihydropterin compounds to the corresponding pterin compounds. For example, sepiapterin (a dihydropterin) is oxidized to oxidized sepiapterin in the presence of this enzyme. The only dihydropterin that has been tested that is not a substrate for this enzyme is dihydroneopterin triphosphate, the compound thought to be a precursor for all naturally occurring pterins and dihydropterins. Since the action of dihydropterin oxidase is reduced significantly when the concentration of oxygen is very low, it is likely that this enzyme uses molecular oxygen as the oxidizing agent during the oxidation of dihydropterins. Neither NAD+ or NADP+ is required. In the presence of the two enzymes dihydropterin oxidase and biopterin synthase, sepiapterin is converted to biopterin. However, in the presence of biopterin synthase alone, sepiapterin is converted to dihydrobiopterin.
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    Theoretical and applied genetics 55 (1979), S. 231-238 
    ISSN: 1432-2242
    Keywords: Drosophila melanogaster ; Scute locus ; Maps ; Operon-like model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The functional expression of 12 scute alleles in homozygotes and compounds of Drosophila melanogaster at 14°, 22°, 30°C is analysed. Based on the data obtained, linear maps for bristles and mutations are built. The basic features of the maps, clustering and polarity, are invariable with respect to temperature, scute gene dosage and cross direction. In addition local dominance of the norm over bristle reduction was produced by the scute mutation; different types of complementation reactions were established for each bristle. The gene scute is treated as an operon-like system, composed of 3–4 cistrons with each controlling the formation of bristles on a particular region of the fly's body. This model argues well with the structure of maps constructed and implies a post-translational level of initial events of bristle-formation process.
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  • 88
    ISSN: 1615-6110
    Keywords: Onagraceae ; Oenothera sect.Oenothera subsect.Raimannia, subsect.Euoenothera, subsect.Munzia, subsect.Emersonia ; Chromosomal analysis ; plastid analysis ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Based on an analysis of results from experimental hybridization, the plants assigned byMunz toOenothera subg.Oenothera and subg.Raimannia, now divided into approximately 76 species, are referred to a single section,Oenothera. This section is in turn divided into five subsections:Euoenothera, Munzia, Raimannia, Emersonia, and an undescribed group of three species related toOenothera pubescens. Euoenothera is maintained in the traditional sense, and includes about 14 species of North America, widely naturalized elsewhere.Munzia consists of 45 species, comprising three series, and native to South America.Raimannia is restricted to a group of approximately 11 North American species.Emersonia comprises four rather heterogenous species of northern Mexico and southern New Mexico, of whichOenothera macrosceles, O. maysillesii, andO. organensis have been described. Within these four subsections, interspecific hybrids can be made in general, although plastid differentiation often leads to incompatibilities. With varying degrees of difficulty, hybrids were produced in all intersectional combinations involvingEuoenothera, Emersonia, Munzia, andRaimannia, the most difficult being those betweenEmersonia andRaimannia. Based on their habit and distribution,Emersonia species, and especiallyOenothera maysillesii, appear to resemble most closely the common ancestor of the section,Euoenothera andMunzia to have been derived from it or its common ancestor, andRaimannia perhaps to be more closely related to the phylogenetic branch that leads toEuoenothera.
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    Plant systematics and evolution 133 (1979), S. 87-94 
    ISSN: 1615-6110
    Keywords: Fabaceae ; Trigonella ; T. foenum-graecum ; T. berythaea ; T. macrorrhyncha ; T. gladiata ; Seed protein electrophoresis ; taxonomy ; cultivated plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The seed proteins ofTrigonella foenum-graecum, T. berythaea, T. macrorrhyncha andT. gladiata were fractionated on polyacrylamide gels in anodic and cathodic systems. Similarity indices between the profiles of any two species indicated close affinity betweenT. gladiata andT. macrorrhyncha and betweenT. foenum-graecum andT. berythaea. It has been pointed out that according to morphological resemblance and similarity index of the seed protein profileT. berythaea is closer to the cultigen than any other species of sectionFoenum-graecum, but these two species are strongly isolated from one another by the albino seedlings of their F1 hybrids.
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    Euphytica 28 (1979), S. 685-696 
    ISSN: 1573-5060
    Keywords: Solanum sucrense ; taxonomy ; crossability ; field studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Two theories for the origin of the Bolivian weed potato species Solanum sucrense Hawkes have been tested. The first was that it had an allopolyploid origin as a hybrid of the cultivated tetraploid S. tuberosum ssp. andigena (Juz. et Buk.) Hawkes with the wild/weed tetraploid cytotype of S. oplocense Hawkes. The second hypothesis postulated that it was a cross of the weed diploid species S. sparsipilum (Bitt.) Juz. et Buk. with S. oplocense. Synthetic hybrids of S. tuberosum ssp. andigena x S. oplocense and of S. sparsipilum x S. oplocense have been compared morphologically with S. sucrense accessions. Their crossability has also been investigated. The crossability and morphological studies strongly suggested that the former hypothesis was the more likely. This was borne out by observations made on the 1974 University of Birmingham Expedition when segregating populations of S. sucrense and S. oplocense were collected growing with feral S. tuberosum ssp. andigena. The evidence from this study indicates that the S. tuberosum ssp. andigena x S. oplocense hybrid has formed the basis of the S. sucrense gene pool. It is suggested that this hybridogenic taxon be maintained under the name Solanum x sucrense. The clarification of the taxonomic relationships of these three species will be of interest to Globodera resistance breeders, in view of the fact that these taxa are resistant to various pathotypes of the golden nematode.
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    Behavior genetics 9 (1979), S. 123-128 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; phototaxis ; X chromosome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Strains ofDrosophila melanogaster differ in their phototactic responses to red light (654 nm). Genes located on all three major chromosomes are involved in influencing the response, but the X chromosome and third chromosome account for most of the variation in phototaxis.
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    Behavior genetics 9 (1979), S. 129-134 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; D. simulans ; larval feeding behavior ; egg-to-adult viability ; isofemale line
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Larval feeding behavior of isofemale lines of the sibling speciesDrosophila melanogaster andD. simulans was investigated. This behavior was measured as the number of cephalopharyngeal retractions of individual larvae per 30 sec period (CPR score) in different generations (G0, G1, and G14). In addition, egg-to-adult viability was estimated in each isofemale line. The results were as follows: (1) In either species, there was variation of CPR score among individuals and among isofemale lines. Although no differences of CPR score were found among experimental groups (generations) and between species, there was a significant difference among isofemale lines. (2) The behavioral trait was stable through generations in each isofemale line. (3) This behavior was correlated with egg-to-adult viability, showing that it is important for the development of the fly.
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    Behavior genetics 9 (1979), S. 209-217 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; D. simulans ; D. pseudoobscura ; pupation height ; geotaxis ; species differences ; selection for pupation height
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Pupation heights of various natural and laboratory populations ofDrosophila melanogaster, D. simulans, andD. pseudoobscura were observed in the laboratory under conditions of continuous darkness or continuous light. Generally higher mean pupation heights were observed under conditions of darkness.D. melanogaster tended to pupate higher than theD. pseudoobscura populations, andD. pseudoobscura tended to pupate higher thanD. simulans. The order of these species differences was similar whether pupation was measured in light or in darkness. Results of selection for pupation height inD. melanogaster suggest the presence of genetic variation for this character. The possibility that a relationship exists between adult and larval behaviors was explored by measuring the pupation heights of larvae from strains selected for geotactic behavior as adults, and also by measuring geotaxis of adults from strains selected for pupation height.
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    Behavior genetics 9 (1979), S. 257-275 
    ISSN: 1573-3297
    Keywords: sexual behavior ; Drosophila melanogaster ; genetic mosaics ; ontogeny of behavior ; wing vibration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract The sex appeal of aDrosophila melanogaster female is defined here as the stimulus (or set of stimuli) which induces wing vibration in courting males. A quantitative measure of sex appeal is the cumulative duration of wing vibration induced by a given female averaged over several consecutive test intervals using different standardized male testers (sex appeal parameter, SAP). By use of SAP, both males and females are found to have the same amount of sex appeal on the first day after eclosion. However, males rapidly lose it by the next day, so that mature males become distinct from females. We report the ontogeny of the male's response to sex appeal. By the SAP method, we also demonstrate that the male's response is dependent on his previous encounter with females. The sex appeal of 287 gynandromorphs was examined in order to localize the sex appeal focus by means of blastoderm fate mapping. Most mosaic flies were classified as either positive (femalelike, with high SAPs) or negative (malelike, with SAPs of zero). Sixteen percent of the gynandromorphs had intermediate levels of SAP, inducing only short vibrations, a response which males rarely give to normal females. Assuming that the gynanders with such intermediate sex appeal must have both female and male foci, distances to the foci from external landmarks were calculated. The center of the focus seems to be an internal structure mapping to the ventroposterior region of the blastoderm fate map, close to the primordia of the anterior sternites. The focus might include a large mesodermal area, but only part of it must have a female genotype for the sex appeal to be expressed. A possible involvement of the fat bodies in production of the sex appeal stimulus is discussed in relation to these findings. Consistent with this conclusion is the fact that females whose abdomens were amputated still retain enough sex appeal to induce male wing vibrations.
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  • 95
    ISSN: 1573-3297
    Keywords: aristal morphology ; Drosophila melanogaster ; artificial selection ; geotaxis ; mating behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract The aristae ofDrosophila have been shown to play a role in mating behavior and geotaxis. Two populations ofD. melanogaster were selected for increased and decreased numbers of major aristal branches. Selection was successful and resulted in two lines differing by an average of six aristal branches. Hybridization analyses of selected lines revealed that genes influencing aristal branching are located on both the X chromosome and the autosomes. Polygenic control of aristal morphology is indicated by a gradual response to selection and low realized heritabilities. When selection was relaxed for 19 generations, the number of aristal branches did not revert to the number in the control line. Changes in aristal branching did not appear to have a consistent influence on geotaxis, although there was a tendency for flies with fewer aristal branches to be geonegative. Neither mating speed nor ethological isolation between the two populations was affected by selection. It is concluded that the number of aristal branches inDrosophila is a neutral trait (i.e., not subject to natural selection) under laboratory conditions. Correlations between aristal morphology and behavior found in other selection experiments by previous investigators were likely due to linkage disequilibria.
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  • 96
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    Behavior genetics 9 (1979), S. 407-412 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; oviposition site preference ; substrate temperature ; heritability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Drosophila melanogaster females from a multifemale stock (SC-1) showed strong oviposition site preference (OSP) in a continuous gradient of substrate temperatures (18–31°C). Flies reared at 25°C had an OSP ( $$\bar X$$ ±SE) of 25.2±0.2°C, whereas flies reared at 18°C had an OSP of 23.5±.2°C. Flies reared from egg to adult at one temperature and exposed as adults for 4 days to another temperature had OSPs intermediate between these extremes. This second 4-day exposure seemed to have a greater effect on OSP than the first rearing temperature. Selection experiments failed to produce significant change in mean OSP in eight generations, indicating a low heritability of temperature OSP in this stock.
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  • 97
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    Behavior genetics 9 (1979), S. 425-429 
    ISSN: 1573-3297
    Keywords: random mating ; Drosophila pseudoobscura ; pheromones ; Drosophila melanogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Inbreeding, up to 12 generations of single-pair matings, did not cause significant deviation from random mating among two sets of strains inDrosophila pseudoobscura. This contrasts with reports that inbreedingD. melanogaster induces negative assortative mating among lines.
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  • 98
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    Behavior genetics 9 (1979), S. 543-553 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; divergent selection ; locomotor activity ; heritability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Selection for high and low locomotor activity has been applied in two base populations ofDrosophila melanogaster of distinct geographical origin. From each base population a high and a low line were selected, in which anesthesia was performed with ether. In addition, from one of the base populations a high line and a low line were selected under CO2 narcosis. Locomotor activity was measured in an apparatus consisting of rows of 20 tubes in a line. Heritabilitities in the base populations determined in progeny tests were approximately 10%. Divergent directional selection was successful with realized heritabilities of similar value.
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  • 99
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; locomotor activity ; mating preference ; sexual isolation ; fertility ; selected lines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Tests for reproductive isolation between lines selected for locomotor activity were performed. Three sets of selection lines were used, each consisting of lines selected for low and high locomotor activity from the same base population. Females preferred high-activity males in almost every case. However, in one of the sets temporary sexual isolation was found between flies of the high and low lines. This was accompanied in the low-activity females with a higher fertility when they were mated with their own males. After further selection the partial isolation disappeared.
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  • 100
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    Behavior genetics 9 (1979), S. 563-570 
    ISSN: 1573-3297
    Keywords: Drosophila melanogaster ; locomotor activity ; genetic analysis ; X chromosome ; selected lines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Divergent directional selection produced three pairs of lines each consisting of a line with high and a line with low locomotor activity. Reciprocal crosses between the high and low lines of one of these pairs showed that a considerable part of the activity differences was contributed by differences between the X chromosomes. This was confirmed by a substitution of the three large chromosomes, between the low and the high lines. The two large autosomal chromosomes had only minor effects. Interactions between chromosomes were sometimes significant. Low-activity alleles tended to be dominant over alleles for high activity.
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