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1.
The penile morphologies of nocturnal prosimians are complex and vary considerably between genera and species. Accordingly, comparative morphology can be useful in taxonomic studies, particularly when assessing the status of newly discovered species. I measured features of penile morphology—surface area of the glans penis; shape and size of the keratinized spines on the glans—for populations representing 14 species within the subfamily Galagoninae. Intraspecific variations in penile morphology were relatively minor. By contrast, there are significant differences in several morphological features among closely related, sympatric species, e.g., in the greater bush babies (Otolemur crassicaudatus and O. garnettii) and lesser bush babies (Galago senegalensis and Galago moholi). Assessment of glans area resulted in the recognition of a second needle-clawed form: Euoticus pallidus. Similar divisions exist in the dwarf and greater bush babies with respect to proportional spiny area and characteristics of spine size. I constructed a key based on the presence/absence of certain features—penile spines, dermal markings on the glans, penile lappets—as well as the shape of the baculum and possession of different spinal morphotypes. This key may be used to identify all 14 species of bush babies. Penile morphologies provide a useful guide to specific identity in the Galagoninae, which may be true also for other groups of nocturnal mammals.  相似文献   

2.
Morphology is not a reliable specific indicator in nocturnal animals. Nevertheless, because species are genetically independent, appropriate analytic methods should reveal subtle and consistent morphological differences among them. Until recently, the diversity of living bush babies was underrated, and new species have been recognized on the basis of genetic, behavioral and soft tissue data. This has placed museum curators in a quandary as to how to sort their skin and skull collections according to the new specific designations.We conducted multivariate analyses of 6 morphologically similar pairs of bush baby taxa: Otolemur crassicaudatus and O. garnettii; Galagoides demidoffand G. thomasi; Galago gallarumand G. senegalensis; G. moholi and G. senegalensis; Euoticus elegantulus and E. pallidus, and Galagoides zanzibaricus and G. granti. We also compared subspecies within the taxa Otolemur crassicaudatus, O. garnettii, Galagoides demidoff, and Galago senegalensis.Five out of six species pairs were discriminated with a high level of reliability (88.5–99%) on the basis of 2–5 morphological variables. Only Euoticus elegantulus and E. pallidus did not show this pattern. All strongly supported specific discriminations share two features: (a) ear length is a highly significant factor, while the involvement of other characters is variable; (b) the greater the reliability of the discrimination, the fewer variables necessary to effect it. Euoticus elegantulus and E. pallidus behaved more like subspecies in the discrimination, while Galago senegalensis sspp. showed a pattern of variation similar to that in the specific analyses.  相似文献   

3.
犬科的线粒体细胞色素b DNA序列及其分子系统学研究   总被引:13,自引:0,他引:13  
通过对犬科的赤狐、蓝狐、貉和狼4种的线粒体细胞色素b约372bpDNA片段序列分析,结合GenBank中狗、西门豺和非洲野犬3种的该区段DNA序列的比较,共发现113个核苷酸位点存在变异(约30%)。NJ法构建的分子系统树显示,非洲野犬最先从犬科动物中分化出来;犬属的我狼、狗和西门豺等3种为系统树上独立的一支,且其分歧的时间较赤狐、蓝狐和貉早;赤狐和蓝狐具有较近的亲缘关系。上述结果与形态的观点基本  相似文献   

4.
Li QQ  Zhang YP 《Biochemical genetics》2005,43(7-8):375-386
To study the phylogenetic relationships of the macaques, five gene fragments were sequenced from 40 individuals of eight species: Macaca mulatta, M. cyclopis, M. fascicularis, M. arctoides, M. assamensis, M. thibetana, M. silenus, and M. leonina. In addition, sequences of M. sylvanus were obtained from Genbank. A baboon was used as the outgroup. The phylogenetic trees were constructed using maximum-parsimony and Bayesian methods. Because five gene fragments were from the mitochondrial genome and were inherited as a single entity without recombination, we combined the five genes into a single analysis. The parsimony bootstrap proportions we obtained were higher than those from earlier studies based on the combined mtDNA dataset. Excluding M. arctoides, our results are generally consistent with the classification of Delson (1980). Our phylogenetic analyses agree with earlier studies suggesting that the mitochondrial lineages of M. arctoides share a close evolutionary relationship with the mitochondrial lineages of the fascicularis group of macaques (and M. fascicularis, specifically). M. mulatta (with respect to M. cyclopis), M. assamensis assamensis (with respect to M. thibetana), and M. leonina (with respect to M. silenus) are paraphyletic based on our analysis of mitochondrial genes.  相似文献   

5.
Head-cocking is rotation of the head about the rostrocaudal axis with a fixed direction of orientation. The behavior is a response to either visual or auditory stimuli according to species. Although head-cocking is prevalent in small primates, its functional significance is unclear. We studied head-cocking in response to a variety of novel visual and acoustic stimuli in Garnett's greater bush babies (Otolemur garnettii). We systematically varied stimulus type (animate vs. inanimate image) and mode of presentation (NON-VIDEO vs. VIDEO) to assess their effects on the head-cocking response. A higher incidence of head-cocking occurred with novel animal images and for NON-VIDEO presentations. Acoustic stimuli suppressed rather than facilitated head-cocking. Juveniles head-cocked much more than adults did. Clearly head-cocking in Otolemur garnettii is primarily involved in visual rather than auditory function. It does not serve simple sensory/perceptual functions such as depth perception or acuity. Instead, in consideration of the importance of novelty to the elicitation of the behavior, the higher incidence in younger animals, and the structure of the visual system, we propose that head-cocking is a motor strategy to encode the parameters of novel images in the process of form learning.  相似文献   

6.
Many diurnal anthropoid species direct social behaviors toward their own mirror-image as though viewing a conspecific. To determine whether a nocturnal prosimian species would behave similarly, we videotaped social responses of 45 Garnett's greater bush babies (Otolemur garnettii) observing mirror-images for the first time, scored them for frequency and duration, and compared them with the same behaviors directed elsewhere in the test apparatus. Males scentmarked more than females did, principally with the hindfoot, and most when in immediate proximity to the mirror. Bush babies displayed bipedal posture and threat gestures when oriented directly toward a mirror from a near position. Orientation toward the mirror also increased the frequency of arched-back postures; however, this behavior was not contingent on proximity to the mirror or visibility of the mirror-image. The differential expression of specific behaviors toward mirror-images by male and female bush babies supports the view that this nocturnal prosimian, thought to be dependent on olfaction and audition for communication, is capable of specific recognition by visual cues alone.  相似文献   

7.
An altered pattern of epigenetic modifications, such as DNA methylation and histone modification, is critical to many common human diseases, including cancer. Recently, mitochondrial DNA (mtDNA) was reported to be associated with tumorigenesis through epigenetic regulation of methylation patterns. One of the promising approaches to study DNA methylation and CpG islands (CGIs) is sequencing and analysis of clones derived from the physical library generated by methyl-CpG-binding domain proteins and restriction enzyme MseI. In this study, we observed that the most redundant sequences of 349 clones in a human CGI library were all generated from the human mitochondrial genome. Further analysis indicated that there was a 5,845-bp DNA transfer from mtDNA to chromosome 1, and all the clones should be the products of a 510-hp MseI fragment, which contained a putative CGI of 270 bp. The 510-bp fragment was annotated as part of cytochrome c oxidase subunit Ⅱ (COXⅡ), and phylogenetic analysis of homologous sequences containing COXII showed three DNA transfer events from mtDNA to nuclear genome, one of which underwent secondary transfer events between different chromosomes. These results may further our understanding of how the mtDNA regulates DNA methylation in the nucleus.  相似文献   

8.
从线粒体细胞色素b探讨长臀鲃属三个种分类与进化的关系   总被引:10,自引:1,他引:10  
本研究测定了长臀属(MystacoleucusG櫣nther)中的3个种 :月斑长臀(M.chilopterusFowler)、长臀[M.marginatus(CuvieretValenciennes)]和细尾长臀(M.lepturusHuang)共22个个体的线粒体细胞色素b部分基因片段 ,其序列为408bp,并选用亚科(Acheilognathinae)中华(RhodeussinensisG櫣nther)及亚科(Barbinae)中的云南倒刺(Spinibarbus.denticulatusyunnanensisTsu)作为外群。结果表明 :细尾长臀与月斑长臀、长臀间存在遗传分化 ,分化程度与鲤科其它鱼类相似 ;而月斑长臀和长臀却无法分开。结果提示 ,月斑长臀和长臀很可能为同一个种。此外 ,长臀属与云南倒刺的亲缘关系较近 ,表明有争议的长臀属归入亚科是合理的。  相似文献   

9.
Mitochondrial DNA sequences of selected regions of the small subunit and large subunit ribosomal RNAs and cytochrome b genes were analyzed for 10 gadid species, representing 8 genera within Gadidae, and 10 species representing 5 other gadiform families. Phylogenetic analyses revealed that Gadiculus is the most basal gadid genus, and that Trisopterus and Micromesistius constitute a relatively basal clade. Lotidae was identified as the family most closely related to Gadidae. Estimation of divergence times indicated that the most ancient Gadidae split between Gadiculus and the remaining gadid genera occurred about 20 million years ago. The clade including the most recent species (Gadus, Boreogadus, Merlangius, Melanogrammus, and Pollachius) diverged from the Trisopterus/Micromesistius clade approximately 12 million years ago.  相似文献   

10.
用mtDNA D-环序列探讨蒙古和中国绵羊的起源及遗传多样性   总被引:16,自引:0,他引:16  
为了在分子水平上探讨绵羊的起源,对中国和蒙古共20个绵羊群体、314只绵羊mtDNA D-环的部分序列进行了测定,结果表明:中国绵羊和蒙古绵羊mtDNA D-环区的部分序列中A、T、G、C含量没有明显的差别;蒙古绵羊的多态位点数(28.85%)略高于中国绵羊(24.22%);中国绵羊群体的单倍型多样度在青海藏羊、甘肃藏羊、甘肃高山细毛羊、青海细:色羊、甘南藏羊、小尾寒羊和滩羊群体中较高,但在湖羊和岷县黑裘皮羊中较低;蒙古绵羊的单倍型多样度在Bayad和Baidrag群体中最高,但在Gobi—Altai群体中最低。从总体上看,蒙古绵羊的遗传多样性要略高于中国绵羊,例如单倍犁比例的平均值为86.06%(142/185):78.83%(108/137),单倍型多样度(Hd)的甲均值为0.976:0.936,核苷酸多样度(Pi(π))的平均值为0.036:0.034,平均核苷酸差异数(k)的平均值为23.50:22.48~217个中国和蒙古绵羊的单倍型序列的系统发生分析表明,中国和蒙古绵羊均有3个母系起源,被定义为A、B和C3类主要的单倍型。其中A类单倍型在所有中国绵羊群体及绝大多数蒙古绵羊群体(9/11)中占优势,平均比例为58.73%;B类单倍型居中,为24.88%;C类单倍型最少,仅为16.59%。进一步从GenBank获得的91个绵羊D-环区的序列与中国和蒙古绵羊D-环区的单倍型的进行网络关系分析,发现欧洲摩弗仑羊(European mouflon,O.musimon)与中国和蒙古绵羊具有较近的亲缘关系,但没有发现塬羊(Argali.O.ammon)、盘羊(0.rignei bochariensis)和东方盘羊(0.ammon nigrimontana)对中国和蒙古绵羊起源有贡献的证据。  相似文献   

11.
概述基因序列在双翅目蚤蝇科分子系统学研究中的应用。对蚤蝇科已测序的分类单元和基因序列进行了总结,12S rDNA和16S rDNA应用最广泛,涉及蚤蝇科17个属;获得基因序列最多的是Melaloncha属。蚤蝇科分子系统学研究内容为高级阶元系统发育分析、物种鉴定和隐存种发现。今后蚤蝇科分子系统学研究应增加蚤蝇标本的种类与数量,选择标准化基因。  相似文献   

12.
方晨晨  郭晓华  刘广纯  张卓 《昆虫知识》2012,49(4):1048-1055
基因序列分析是揭示金龟总科系统发育关系的重要工具。统计了应用于金龟总科中13个科的线粒体和核基因序列,综述了COⅠ、16S rRNA、28S rRNA、18S rRNA等基因序列在金龟总科分子系统学研究的新进展,探讨了不同基因序列在分类鉴定、隐存种发现、系统发育关系重建等方面的作用,对未来研究趋势进行了展望,为进一步阐明金龟总科系统发育机制奠定基础。  相似文献   

13.
该文测序了湾鳄的线粒体基因组全序列,全长为16,917bp。湾鳄mtDNA结构与其他脊椎动物相似,由22个tRNA,2个rRNA和13个蛋白质编码基因及1个非编码的控制区(D-loop)所组成。除NADH6和tRNAGln、tRNAAla、tRNAAsn、tRNACys、tRNATyr、tRNASer(UCN)、tRNAGlu、tRNAPro在L-链上编码之外,其余基因均在H-链编码。基因排列顺序与已测序的鳄类一致,这显示了鳄类线粒体基因排列顺序上的保守性。但鳄类线粒体基因排列顺序与脊椎动物的典型排列方式相比,有较大的差异,尤其是tRNAPhe基因的重排、tRNASer-tRNAHis-tRNALeu基因族的排列方式等。湾鳄mtDNA和已测序的鳄类一样,缺失轻链复制起始点(OLR)。基于17种鳄mtDNA控制区保守区,采用PAUP4.0最大简约法(Maximumparsimony,MP)构建MP树,邻接法(Neighbor-joiningmethod,NJ)构建NJ树,结果显示:食鱼鳄(Gavialisgangeticus)和假食鱼鳄(Tomistomaschlegelii)聚为一支后再与鳄科(Crocodylidae)的其他物种形成姐妹群,这与基于食鱼鳄和假食鱼鳄的线粒体全序列的分析结果一致,支持将食鱼鳄并入鳄科的观点。结果还支持非洲窄吻鳄(Crocodyluscataphractus)与鳄属(Crocodylus)构成姐妹群,可以单独划分为属的观点。  相似文献   

14.
Data and explicit taxonomic ranking criteria, which minimize taxonomic change, provide a scientific approach to modern taxonomy and classification. However, traditional practices of opinion-based taxonomy (i.e., mid-20th century evolutionary systematics), which lack explicit ranking and naming criteria, are still in practice despite phylogenetic evidence. This paper discusses a recent proposed reclassification of weevils that elevates bark and ambrosia beetles (Scolytinae and Platypodinae) to the ranks of Family. We demonstrate that the proposed reclassification 1) is not supported by an evolutionary systematic justification because the apparently unique morphology of bark and ambrosia beetles is shared with other unrelated wood-boring weevil taxa; 2) introduces obvious paraphyly in weevil classification and hence violates good practices on maintaining an economy of taxonomic change; 3) is not supported by other taxonomic naming criteria, such as time banding. We recommend the abandonment of traditional practices of an opinion-based taxonomy, especially in light of available data and resulting phylogenies.  相似文献   

15.
从细胞色素b基因序列变异分析中国鲇形目鱼类的系统发育   总被引:18,自引:0,他引:18  
采用PCR技术获得中国鲇形目鱼类11科24属27个代表种类细胞色素b基因1138bp全序列,比较分析了来自北美洲、非洲的部分鲇形目鱼类同一基因序列,并选取脂鲤目、鲤形目和鲱形目鱼类作外类群,采用Bayesian方法和最大简约法(MP)构建分子系统树。结果表明:(1)鲇形目鱼类细胞色素b基因序列中,与脂鲤目、鲤形目以及鲱形目鱼类相比存在3bp的缺失;(2)鲇形目鱼类各科代表种类形成一单系群;(3)两种建树方法均支持铫科、粒鲇科和钝头鮠科形成一单系群;而胡子鲇科、刀鲇科、海鲇科、鮰科、长臀鮠科、鲢科、鲇科、棘脂鲿科、鲿科形成一大的单系群;但鳗鲇科的系统位置两种建树方法没有取得一致结果;而其中长臀鲍科与北美的鮰科形成姐妹群,胡子鲇、鮰科、鲇科、鲿科和鮡科是较明显的单系群。  相似文献   

16.
A population genetic analysis based on sequences of the mitochondrial control region in 110 red foxes from five sampling localities in northern Serbia was carried out. The analysis yielded nine different haplotypes. Neither haplotype phylogeny nor their distribution was in accordance with the geographic location of the populations. In particular, the data failed to detect an unequivocal influence of the two big rivers, the Danube and the Tisza, separating the populations studied. Population differentiation was altogether low, without any relationship to the rivers as possible migration barriers. Although the possibility of foxes crossing the rivers over bridges or by swimming, thus keeping up gene flow, cannot be ruled out, it is most probable that the control region sequences are not sensitive enough to resolve small-scale population relationships but rather show patterns determined by stochastic processes such as genetic drift or lineage sorting.  相似文献   

17.
Aimed to evaluate the phylogenetic position of the recently described Protobothrops dabieshanensis Huang et al. (2012), phylogenic relationships of 12 species within Protobothrops based on four mtDNA gene fragments (12S RNA, 16S RNA, ND4 and Cyt b) were reconstructed in our study. The result indicates a clade composed ofP dabiesha- nensis, P. jerdonii and P xiangchengsis with strong support. The genetic distance among P dabieshanensis, P jerdonii and P xiangchengsis was much lower than other congeners. Based on the data from the phylogenetic analysis and pre- viously described morphological differences, we conclude that P dabieshanensis is a valid species with close affinities to P jerdonii and P xiangchengsis.  相似文献   

18.
The nucleotide sequence data for yeast mitochondrial ribosomalprotein (MRP) genes were analyzed by the computer program GeneMarkwhich predicts the presence of likely genes in sequence databy calculating statistical biases in the appearance of consecutivenucleotides. The program uses a set of standard sequence datafor this calculation. We used this program for the analysisof yeast nucleotide sequence data containing MRP genes, hopingto obtain information as to whether they share features in commonthat are different from other yeast genes. Sequence data setsfor ordinary yeast genes and for 27 known MRP genes were used.The MRP genes were nicely predicted as likely genes regardlessof the data sets used, whereas other yeast genes were predictedto be likely genes only when the data set for ordinary yeastgenes was used. The assembled sequence data for chromosomesII, III, VIII and XI as well as the segmented data for chromosomeV were analyzed in a similar manner. In addition to the knownMRP genes, eleven ORF's were predicted to be likely MRP genes.Thus, the method seems very powerful in analyzing genes of heterologousorigins.  相似文献   

19.
Complete or nearly complete mitochondrial DNA sequences were determined from four lizards (Western fence lizard, Warren's spinytail lizard, Terrestrial arboreal alligator lizard, and Chinese crocodile lizard) and a snake (Texas blind snake). These genomes had a typical gene organization found in those of most mammals and fishes, except for a translocation of the glutamine tRNA gene in the blind snake and a tandem duplication of the threonine and proline tRNA genes in the spinytail lizard. Although previous work showed the existence of duplicate control regions in mitochondrial DNAs of several snakes, the blind snake did not have this characteristic. Phylogenetic analyses based on different tree-building methods consistently supported that the blind snake and a colubrid snake (akamata) make a sister clade relative to all the lizard taxa from six different families. An alternative hypothesis that snakes evolved from a lineage of varanoids was not favored and nearly statistically rejected by the Kishino-Hasegawa test. It is therefore likely that the apparent similarity of the tongue structure between snakes and varanoids independently evolved and that the duplication of the control region occurred on a snake lineage after divergence of the blind snake.  相似文献   

20.
Part of the 12S rDNA gene was amplified and sequenced for 11 placental mammals, 3 marsupials, and 2 monotremes. Multiple alignments for these sequences and nine additional placental sequences taken from GenBank were obtained using CLUSTAL. Phylogenetic analyses were performed using standard parsimony, transversion parsimony, and Lake's method of invariants. All of our analyses uniteLoxodontia withDugong. Procavia, in turn, is a sister group to these taxa, thus supporting the monophyly of the Paenungulata. Perissodactyls are a sister group to paenungulates when transitions and transversions are both included but not when transitions are omitted. Likewise, cetaceans are a sister group to artiodactyls on minimum length trees under standard parsimony but not under transversion parsimony. Rodent monophyly and bat monophyly also receive mixed support, as does a putative alliance between primates and lagomorphs. Interestingly, the percentage divergence between the echidna and the platypus is less than for the rat and mouse.  相似文献   

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