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1.
The species of Diadegma that attack Plutella xylostella (Linnaeus) are revised. Following a morphometric study involving principal components and discriminant analyses, seven distinct morphospecies are recognized. One species is described as new: D. novaezealandiae from New Zealand. Diadegma mollipla (Holmgren) is the name for the species from sub-Saharan Africa and some Indian Ocean and South Atlantic islands. Diadegma varuna Gupta syn. nov. and D. niponica Kusigemati syn. nov. are both synonymized with D. fenestrale (Holmgren). Diadegma xylostellae Kusigemati is strongly presumed to be a synonym of D. semiclausum (Hellén). An illustrated identification key is provided and each species is described in a standard way.  相似文献   

2.
Transposable elements (TEs) make up around 10%-15% of the Drosophila melanogaster genome, but its sibling species Drosophila simulans carries only one third as many such repeat sequences. We do not, however, have an overall view of copy numbers of the various classes of TEs (long terminal repeat [LTR] retrotransposons, non-LTR retrotransposons, and transposons) in genomes of natural populations of both species. We analyzed 34 elements in individuals from various natural populations of these species. We show that D. melanogaster has higher average chromosomal insertion site numbers per genome than D. simulans for all TEs except five. The LTR retrotransposons gypsy, ZAM, and 1731 and the transposon bari-1 present similar low copy numbers in both species. The transposon hobo has a large number of insertion sites, with significantly more sites in D. simulans. High variation between populations in number of insertion sites of some elements of D. simulans suggests that these elements can invade the genome of the entire species starting from a local population. We propose that TEs in the D. simulans genome are being awakened and amplified as they had been a long time ago in D. melanogaster.  相似文献   

3.
Widely regarded beliefs aboutDrosophila histone gene copy numbers and developmental requirements have been generalized from fairly limited data since studies on histone gene arrangements and copy numbers have been largely confined to a single species,D. melanogaster. Histone gene copy numbers and chromosomal locations were examined in three species:D. melanogaster, D. hydei andD. hawaiiensis. Quantitative whole genome blot analysis of DNA from diploid tissues revealed a tenfold variability in histone gene copy numbers for these three species. In situ hybridization to polytene chromosomes showed that the histone DNA (hDNA) chromosomal location is different in all three species. These observations lead us to propose a relationship between histone gene reiteration and chromosomal position.  相似文献   

4.
Flourensia (Asteraceae, Heliantheae, Enceliinae) is an amphitropical genus of resinous subshrubs, shrubs and small trees with 13 North American and 20 South American species among which disagreement on the species limits of some members still exists. To resolve the taxonomy of the South American taxa, we carried out a combination of clustering (Ward's method with Gower distance coefficient) and ordination analyses (Principal Coordinate Analyses) based on 34 vegetative and reproductive characters scored from herbarium material, including types. Based on the results, we recognize 12 South American species: F. angustifolia, F. cajabambensis, F. fiebrigii, F. heterolepis, F. hirtissima, F. macrophylla, F. niederleinii; F. peruviana, F. polycephala, F. thurifera, F. tortuosa and F. suffrutescens. A number of species are placed in synonymy: Flourensia blakeana and F. hirta are synonymized under the name F. fiebrigii; Flourensia campestris, F. leptopoda, F. oolepis and F. riparia are synonymized under F. thurifera; Flourensia macroligulata is synonymized under F. tortuosa, and Flourensia polyclada is synonymized under F. suffrutescens. A taxonomic treatment of four redefined species as well as a key and distribution maps to all South American Flourensia species are provided.  相似文献   

5.
Barbash DA  Ashburner M 《Genetics》2003,163(1):217-226
Hybrid daughters of crosses between Drosophila melanogaster females and males from the D. simulans species clade are fully viable at low temperature but have agametic ovaries and are thus sterile. We report here that mutations in the D. melanogaster gene Hybrid male rescue (Hmr), along with unidentified polymorphic factors, rescue this agametic phenotype in both D. melanogaster/D. simulans and D. melanogaster/D. mauritiana F(1) female hybrids. These hybrids produced small numbers of progeny in backcrosses, their low fecundity being caused by incomplete rescue of oogenesis as well as by zygotic lethality. F(1) hybrid males from these crosses remained fully sterile. Hmr(+) is the first Drosophila gene shown to cause hybrid female sterility. These results also suggest that, while there is some common genetic basis to hybrid lethality and female sterility in D. melanogaster, hybrid females are more sensitive to fertility defects than to lethality.  相似文献   

6.
7.
Echinoderes andamanensis sp. nov. is described from the Andaman Islands (Bay of Bengal, Indian Ocean). Unlike most members of this genus, this new species lacks middorsal spines. It is further distinguished by the presence of lateral spines on segments 4, 10 and 11 in the female and 4, 10–12 in the inale. Collected with E. andamanensis were specimens of E. ehlersi previously known only from a single specimen collected in 1885 in Zanzibar. The Andaman Island females have shorter spines than the males. Additional species include Catena gerlachi , previously known only from Walcair, India. A single juvenile exuvium of Pynophyes sp. was also found. The taxonomic relationships of the species and other members of the genus are discussed.  相似文献   

8.
Drosophila simulans isofemale lines from Africa, South America, and two locations in North America were surveyed for variation at 16 microsatellite loci on the X, second, and third chromosomes, and 18 microsatellites, which are unmapped. D. simulans is thought to have colonized New World habitats only relatively recently (within the last few hundred years). Consistent with a founder effect occurring as colonizers moved into these New World habitats, we find less microsatellite variability in North and South American D. simulans populations than for an African population. Population subdivision as measured at microsatellites is moderate when averaged across all loci (FST = 0.136), but contrasts sharply with previous studies of allozyme variation, which have showed significantly less differentiation in D. simulans than in D. melanogaster. There are substantially fewer private alleles observed in New World populations of D. simulans than seen in a similar survey of D. melanogaster. In addition to possible differences in population size during their evolutionary histories, varying colonization histories or other demographic events may be necessary to explain discrepancies in the patterns of variation observed at various genetic markers between these closely related species.  相似文献   

9.
We have conducted molecular population genetics analyses to understand the relationships among the transposable elements (TEs) in Drosophila melanogaster, in combination with sequence comparisons of TEs from two related species, D. simulans and D. yakuba. We observed much lower than expected genetic differences among elements, clear evidence for departure from expectations for equilibrium copy numbers and little divergence between species. This suggests that a large proportion of TEs in D. melanogaster had a recent origin as a result of interspecies movement.  相似文献   

10.
The mechanism by which patterns are produced appears to be repeated in each segment of an animal, and it has been proposed that it may even have been conserved in evolution so that different species would have the same system of positional information. This idea has been tested by mixing cells of a defined fragment of the wing disc of Drosophila melanogaster with wing disc fragments of five other dipteran species to assay the ability of these disc fragments to stimulate intercalary regeneration of the D. melanogaster cells. The genetically marked (y; mwh) D. melanogaster fragment was mechanically mixed with wing discs or wing disc fragments of four drosophilids (D. melanogaster as a control, D. virilis, D. hydei, Zaprionus vittiger), of Musca domestica, and of Piophila casei. The mixed aggregates were cultured in vivo for 7 days, then metamorphosed in D. melanogaster larval hosts. The D. melanogaster fragments were only stimulated to regenerate when combined with complementary fragments from D. melanogaster or D. virilis wing discs. In the combination between D. melanogaster and D. hydei, the tissue formed integrated mosaic patterns, but no regeneration ensued. The one positive result (D. melanogaster mixed with D. virilis) shows that positional cues can be exchanged and correctly interpreted between cells of different species. The negative results do not prove that the mechanism for establishing patterns is different in the tested species, but may be due to incompatibilities that are not related to pattern formation.  相似文献   

11.
中国斑粉蝶属分类研究(鳞翅目:粉蝶科)   总被引:2,自引:0,他引:2  
魏忠民  武春生 《昆虫学报》2005,48(1):107-118
系统地整理了中国斑粉蝶属DeliasHübner,1819的全部种类,共11种31亚种,包括3个中国 新记录亚种:倍林斑粉蝶指名亚种D. berinda berinda Moore、洒青斑粉蝶不丹亚种D.Sanaca bhutya Talbot和侧条斑粉蝶帕瓦亚种D. lativitta parva Talbot。提出将D.Lativitta tai Yoshino作为侧条斑粉蝶云南亚种D. lativitta yunnana Talbot的同物 异名,D. patrua guiyangensis Zhou et Zhang作为Delias berinda adelma Mitis的同物异名。阐述了各亚种的主要识别特征及其地理分布,分析了区系成分,并提供了分 种检索表及全部种类的雄外生殖器和大部分种类的雌性外生殖器特征图。附有3新记录亚种和国 内未见标本记载的2种的成虫彩色照片  相似文献   

12.
We investigated the nucleotide composition of five genes, Xdh, Adh, Sod, Per, and 28SrRNA, in nine species of Drosophila (subgenus Sophophora) and one of Scaptodrosophila. The six species of the Drosophila saltans group markedly differ from the others in GC content and codon use bias. The GC content in the third codon position, and to a lesser extent in the first position and the introns, is higher in the D. melanogaster and D. obscura groups than in the D. saltans group (in Scaptodrosophila it is intermediate but closer to the melanogaster and obscura species). Differences are greater for Xdh than for Adh, Sod, Per, and 28SrRNA, which are functionally more constrained. We infer that rapid evolution of GC content in the saltans lineage is largely due to a shift in mutation pressure, which may have been associated with diminished natural selection due to smaller effective population numbers rather than reduced recombination rates. The rate of GC content evolution impacts the rate of protein evolution and may distort phylogenetic inferences. Previous observations suggesting that GC content evolution is very limited in Drosophila may have been distorted due to the restricted number of genes and species (mostly D. melanogaster) investigated.  相似文献   

13.
Abstract The tribe Trypetimorphini, the genus Ommatissus , and its two subgenera and eleven species are redescribed or described as new. Evidence for the monophyly of both the genus and of the tribe to which it belongs is examined; it is concluded that while the genus is monophyletic, the monophyly of the tribe is in doubt. Keys for the separation of the three genera of the tribe and for all of the known species of Ommatissus are presented. A new subgenus of Ommatissus is described: O.(Opatissus) , with the type-species O.vietnamicus . Four new species are described: Ommatissus magribus from Morocco, O.kamerunus from Cameroon, O.natalensis from South Africa and O.vietnamicus from Vietnam. The 'Dubas bug', Ommatissus lybicus Bergevin, formerly regarded as a variety of O.binotatus Fieber, is raised to full species status. Trichoduchus is synonymized with Trypetimorpha resulting in the new combinations Trypetimorpha biermani Dammerman, T.china Wu and T.japonicus Ishihara. Trichoduchus japonicus Fennah is synonymized with Trypetimorpha japonicus Ishihara.  相似文献   

14.
Abstract. The subfamily Cercobarconinae is synonymized with the Trachypetinae, the constituent genera ( Trachypetus Guérin de Méneville, Megalohelcon Turner and Cercobarcon Tobias) are rediagnosed and the species are revised and redescribed. Rhamphobarcon Tobias is synonymized with Megalohelcon Turner, R.mosaicus Tobias is synonymized with M.torresensis Turner, M.uptoni Tobias is synonymized with M.ichneumonoides Tobias, and four species are newly described: M.mouldsi, C.bilobatus, C.grossi and C.niger. Relationships within the subfamily are discussed, as are those of the Trachypetinae to other braconid subfamilies. Comments on the biology and distribution of species are provided, along with an illustrated key to genera and species.  相似文献   

15.
The genus Diaporthe (syn. Phomopsis) comprises important pathogens, endophytes or saprobes with diverse host associations and worldwide distribution. Phomopsis theae is the first and hitherto the only recorded Diaporthe species on Camellia in China. The aim of this study was to investigate the Diaporthe species associated with symptomatic and asymptomatic tissues of Camellia spp. from several provinces in China. Eighty-three strains were isolated in the present study. Based on the multi-locus (ITS, HIS, TEF1, TUB) phylogenetic analyses and phenotypic characters, four novel species (D. apiculata Y.H. Gao & L. Cai, D. compacta Y.H. Gao & L. Cai, D. oraccinii Y.H. Gao & L. Cai, D. penetriteum Y.H. Gao & L. Cai), and three known species (D. discoidispora, D. hongkongensis, D. ueckerae) were identified. Five strains were assigned to D. amygdali species complex and 17 strains to D. eres species complex respectively, but they could not be further identified to species level using current multi-locus phylogenetic analysis and morphological characters. Of the identified species, D. compacta and D. discoidispora are only known as endophytes. Diaporthe hongkongensis is the dominant species on Camellia, accounting for 53.3% of the frequency of occurrence. Diaporthe lithocarpus is synonymized with D. hongkongensis; D. miriciae is synonymized with D. ueckerae. Our study revealed a high diversity of undescribed Diaporthe species on Camellia.  相似文献   

16.
Bacteria in the genus Providencia are pathogens of many organisms, including humans and insects. We and colleagues have isolated five different strains belonging to four distinct Providencia species as natural infections of Drosophila melanogaster captured in the wild. We found that these isolates vary considerably in pathology to infected D. melanogaster, differing in the level of mortality they cause, their ability to replicate within the host and the level that the fly's immune response is elicited. One interesting bacterium was Providencia sneebia, which causes nearly complete mortality and reaches large numbers in the fly but does not elicit a comparably strong immune response. Through coinfection experiments, we determined that P. sneebia avoids recognition by the immune system. We tested for biofilm formation and replication within D. melanogaster cells as possible mechanisms for P. sneebia escape from host immunity, but did not find evidence for either. D. melanogaster and Providencia provide a powerful system for studying general host-pathogen interactions, and for understanding how the well-studied immune model host D. melanogaster interacts with its natural bacterial pathogens.  相似文献   

17.
Four clones containing different transposable elements were isolated from a genomic library of Drosophila algonquin. Each clone was hybridized to salivary-gland chromosomes of three lines of D. algonquin and two lines of D. affinis. The estimated copy number in D. algonquin of the four element families varied from 59 to 333. The occupancy per site varied from 0.64 to 0.75. Thus the transposable portion of the D. algonquin genome is dominated by a few high-copy-number elements, each characterized by high occupancies. The copy number and occupancy values were very similar in D. affinis. This differs from the situation in D. melanogaster mobile middle-repetitive DNA, which has at least 30 and perhaps as many as 100 different families of mobile elements, with copy numbers ranging from 5 to 100. When several lines have been examined, elements in D. melanogaster are revealed to have very low occupancies. The four D. algonquin elements do not hybridize with D. melanogaster DNA, but they did hybridize with 15 obscura-group species, thereby revealing a pattern that is consistent with concerted evolution.  相似文献   

18.
张文燕  张菁  钱远槐  曾庆韬 《遗传》2006,28(5):545-550
通过传统的敲片、Giemsa染色的方法, 本文首次对果蝇属黑腹果蝇种组的5种果蝇 (D. constricta、D. ohnishii、D. ogumai、D. pseudobaimaii、D. tani)染色体的数目和形态进行了分析报道。分析发现:这5个种具有相同的染色体数目(2n=8)和不同的形态。D. pseudobaimaii和D. tani 为2V,1R,1D型;D. constricta染色为2V,1R,1D型且其点状染色体难以辨认;D. ohnishii和D. ogumai 具有相同形态为2V,2R。另外,还发现核型与亲缘关系之间有一定的对应性。  相似文献   

19.
Planococcus pacificus sp.n. is described from the South Pacific, Australia and South East Asia. P.citricus is synonymized with P.citri. A key and illustrations are given to separate the species discussed from each other and from the similar P.ficus group.  相似文献   

20.
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