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1.
Lu S  Yuan ZG  Pang J  Yang D  Yu F  McGuire P  Xie F  Zhang YP 《Biochemical genetics》2004,42(5-6):139-148
To elucidate the phylogeny of the genus Paramesotriton (Caudata: Salamandridae), we investigated three mitochondrial DNA gene fragments (1207 bp in total) of cytochrome b, ND2, and ND4 for its six recognized species. The phylogenetic relationships within Paramesotriton were reconstructed by maximum parsimony (MP) and maximum likelihood (ML) methods. Phylogenetic trees (MP and ML trees) that were constructed from the combined data set of the three gene fragments indicated that all six species of Paramesotriton formed a monophyletic group, with P. caudopunctatus as basal to the other five species. This result suggests that P. fuzhongensis is a valid species in Paramesotriton.  相似文献   

2.
解剖研究了织金瘰螈Paramesotriton zhijinensis骨骼系统的形态结构,对各骨块的形状、位置及与邻近骨块的关系进行了描述,为研究瘰螈属的分类、演化及动物实验提供基础资料.  相似文献   

3.
本文采用组织学和形态学方法对尾斑瘰螈的泌尿器官进行研究。结果表明:尾斑瘰螈的泌尿器官主要包括肾脏、输尿管和膀胱。其肾脏为实质性器官,主要由肾小体、肾小管构成;肾实质出现区域分隔,肾小体数量较少,肾小管分为颈段、近曲小管、中间段、远曲小管;其间未发现淋巴组织以及与生殖有关的结构。输尿管由单层立方上皮过渡到假复层立方上皮;膀胱壁由2~3层细胞变移上皮构成。  相似文献   

4.
The matrilineal genealogy of the genus Paramesotriton is hypothesized based on DNA sequences from mitochondrial NADH subunit two (ND2) and its flanking tRNAs (tRN^Arp and a partial tRNA^Ala). The genealogy identifies a highly divergent, unnamed lineage from Qixiling Nature Reserve, Jiangxi, China and places it as the sister taxon of P. chinensis. The newly discovered population differs from other congeners by several features of external morphology including having large clusters of dark brown conical warts on the dorsum of the head, lateral surface of the body and dorsolateral ridges. Its intermittent dorsal vertebral ridge is the same color as other parts of the dorsum and tail narrows gradually from the base to the tip. Further, the new population differs from all congeners by an uncorrected P-distance of more than 9.38% in ND2. Consequently, we describe the new species of Asian warty newt (Salamandridae) as Paramesotriton qixilingensis sp. nov.  相似文献   

5.

The potentials and limitations of different approaches to revealing species boundaries and describing cryptic species are discussed. Both the traditional methods of species delimitation, mostly based on morphological analysis, and the approaches using molecular markers are considered. Besides, the prospects of species identification using digital image recognition and machine learning are briefly considered. It is concluded that molecular markers provide very important material for species delimitation; the value of these data increases manifold if they can be compared with information on morphology, geographic distribution, and ecological preferences of the studied taxa. In many cases, only a practicing taxonomist who knows his or her group thoroughly can correctly interpret the molecular data and incorporate them into the existing knowledge system in order to make a taxonomic decision.

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6.
Although thrips are globally important crop pests and vectors of viral disease, species identifications are difficult because of their small size and inconspicuous morphological differences. Sequence variation in the mitochondrial COI-5ʹ (DNA barcode) region has proven effective for the identification of species in many groups of insect pests. We analyzed barcode sequence variation among 471 thrips from various plant hosts in north-central Pakistan. The Barcode Index Number (BIN) system assigned these sequences to 55 BINs, while the Automatic Barcode Gap Discovery detected 56 partitions, a count that coincided with the number of monophyletic lineages recognized by Neighbor-Joining analysis and Bayesian inference. Congeneric species showed an average of 19% sequence divergence (range = 5.6% - 27%) at COI, while intraspecific distances averaged 0.6% (range = 0.0% - 7.6%). BIN analysis suggested that all intraspecific divergence >3.0% actually involved a species complex. In fact, sequences for three major pest species (Haplothrips reuteri, Thrips palmi, Thrips tabaci), and one predatory thrips (Aeolothrips intermedius) showed deep intraspecific divergences, providing evidence that each is a cryptic species complex. The study compiles the first barcode reference library for the thrips of Pakistan, and examines global haplotype diversity in four important pest thrips.  相似文献   

7.
We describe a new species from the family Salamandridae from northeastern Hunan Province of China based on morphological and molecular genetic evidences.The new species,Tylototriton liuyangensis,is a member of the T.asperrimus group,and shares a number of similarities with T.wenxianensis and T.broadoridgus.The dorsal surface of the new Tylototriton species is completely black,with nodule-like warts distributed evenly along the lateral margin of dorsal body,and there is no transverse striae between the warts.There are several diagnostic characters of the new species that differ from those of T.wenxianensis and T.broadoridgus as follows:(1)the interorbital space(IOS)is comparatively wide;(2)there is a bony ridge present on the dorsal head surface,running along the upper eyelids;(3)the space between axilla and groin(AGS)is comparatively large,with the mean male AGS approximately equal to 50%of the snout-vent length(SVL)and the mean female AGS being 53%of SVL;and(4)there is a small genital armature on the anterior angle of labial folds present inside the anal fissure of adult males during the breeding season.The result from the molecular phylogenetic analysis of the genus Tylototriton(including the type specimen of the new species)based on the complete DNA sequence of the mitochondrial ND2 gene(1035 bp)indicated that the new species was similar to T.wenxianensis,T.dabienicus,and T.broadoridgus,but formed an independent clade.This result was consistent with the morphological analysis above,supporting that the Liuyang Population represented a distinct species.  相似文献   

8.
Horismenus parasitoids are an abundant and understudied group of eulophid wasps found mainly in the New World. Recent surveys based on morphological analyses in Costa Rica have quadrupled the number of named taxa, with more than 400 species described so far. This recent revision suggests that there is still a vast number of unknown species to be identified. As Horismenus wasps have been widely described as parasitoids of insect pests associated with crop plants, it is of high importance to properly establish the extant diversity of the genus, in order to provide biological control practitioners with an exhaustive catalog of putative control agents. In this study, we first collected Horismenus wasps from wild Phaseolus bean seeds in Central Mexico and Arizona to assess the genetic relatedness of three morphologically distinct species with overlapping host and geographical ranges. Sequence data from two nuclear and two mitochondrial gene regions uncovered three cryptic species within each of the three focal species (i.e., H. missouriensis, H. depressus and H. butcheri). The monophyly of each cryptic group is statistically supported (except in two of them represented by one single tip in which monophyly cannot be tested). The phylogenetic reconstruction is discussed with respect to differences between gene regions as well as likely reasons for the differences in variability between species.  相似文献   

9.
记述采自贵州宽阔水保护区的钩(虫责)属l新种:巨刺钩(虫责)Kamimuria grandispinata Du &Sun,sp.nov.,该新种的阳茎特征与长刺钩虫责K.longispina Wu相似,但长刺钩(虫责)阳茎囊背面近端部有1膜质突起,上面生有粒状微刺,而新种阳茎囊背面近端部是1个近似三角形的刺斑,无突起...  相似文献   

10.
Cryptic species continue to be uncovered in many fish taxa, posing challenges for fisheries conservation and management. In Sardinella gibbosa, previous investigations revealed subtle intra-species variations, resulting in numerous synonyms and a controversial taxonomy for this sardine. Here, we tested for cryptic diversity within S. gibbosa using genetic data from two mitochondrial and one nuclear gene regions of 248 individuals of S. gibbosa, collected from eight locations across the Philippine archipelago. Deep genetic divergence and subsequent clustering was consistent across both mitochondrial and nuclear markers. Clade distribution is geographically limited: Clade 1 is widely distributed in the central Philippines, while Clade 2 is limited to the northernmost sampling site. In addition, morphometric analyses revealed a unique head shape that characterized each genetic clade. Hence, both genetic and morphological evidence strongly suggests a hidden diversity within this common and commercially-important sardine.  相似文献   

11.
贵州淫羊藿属一新种   总被引:17,自引:2,他引:17  
德务淫羊藿新种图1 Epinedium dewuense S. Z. He, Probst et W. F. Xu sp. nov. Fig. 1 Species nova E. sagittato (Sieb. et Zucc. ) Maxim. similis, sed paginis foliorum pilosis, floribus majoribus(circ. 2 cm diam. ), sepalis exterioribus ad medium purpureo-roseis, petalis purepureo-roseis, saccatis, elimbatis,antheris viridulis oblongis 2-1ocularibus, loculis aegualibus parallelis ad maturitatem a basi ad apicem apertis, lobis per-sitentibus revolutis, facile differt.  相似文献   

12.
Coinfections within hosts present opportunities for horizontal gene transfer between strains and competitive interactions between genotypes and thus can be a critical element of the lifestyles of pathogens. Bartonella spp. are Alphaproteobacteria that parasitize mammalian erythrocytes and endothelial cells. Their vectors are thought to be various biting arthropods, such as fleas, ticks, mites, and lice, and they are commonly cited as agents of various emerging diseases. Coinfections by different Bartonella strains and species can be common in mammals, but little is known about specificity and coinfections in arthropod vectors. We surveyed the rate of mixed infections of Bartonella in flea vectors (Polygenis gwyni) parasitizing cotton rats (Sigmodon hispidus) in which previous surveys indicated high rates of infection. We found that nearly all fleas (20 of 21) harbored one or more strains of Bartonella, with rates of coinfection approaching 90%. A strain previously identified as common in cotton rats was also common in their fleas. However, another common strain in cotton rats was absent from P. gwyni, while a rare cotton rat strain was quite common in P. gwyni. Surprisingly, some samples were also coinfected with a strain phylogenetically related to Bartonella clarridgeiae, which is typically associated with felids and ruminants. Finally, a locus (pap31) that is characteristically borne on phage in Bartonella was successfully sequenced from most samples. However, sequence diversity in pap31 was novel in the P. gwyni samples, relative to other Bartonella previously typed with pap31, emphasizing the likelihood of large reservoirs of cryptic diversity in natural populations of the pathogen.  相似文献   

13.
Comparative phylogeography allow us to understand how shared historical circumstances have shaped the formation of lineages, by examining a broad spectrum of co-distributed populations of different taxa. However, these types of studies are scarce in the Neotropics, a region that is characterized by high diversity, complex geology, and poorly understood biogeography. Here, we investigate the diversification patterns of five lineages of amphibians and reptiles, co-distributed across the Choco and Andes ecoregions in northwestern Ecuador. Mitochondrial DNA and occurrence records were used to determine the degree of geographic genetic divergence within species. Our results highlight congruent patterns of parapatric speciation and common geographical barriers for distantly related taxa. These comparisons indicate similar biological and demographic characteristics for the included clades, and reveal the existence of two new species of Pristimantis previously subsumed under P. walkeri, which we describe herein. Our data supports the hypothesis that widely distributed Chocoan taxa may generally experience their greatest opportunities for isolation and parapatric speciation across thermal elevational gradients. Finally, our study provides critical information to predict which unstudied lineages may harbor cryptic diversity, and how geology and climate are likely to have shaped their evolutionary history.  相似文献   

14.
中国鹅膏菌属(担子菌)的物种多样性   总被引:9,自引:3,他引:9  
鹅膏菌属(Amanita)是一个近世界性广布的大属,全球已被描述而又被承认的有近500种。在文献中,我国此属已记载约200种。然而,许多种都是原初描述于欧洲或北美的种类。近来的研究表明,东亚的鹅膏菌独特且有其自身的分布范围。东亚的有些种虽与产于欧洲或北美的某些种相似,但仔细的野外观察,详尽的形态解剖学和分子进化生物学研究结果表明,东亚的鹅膏菌是独立的分类群。在欧洲,人们有采集著名食菌恺撒鹅膏菌的习  相似文献   

15.
16.
Krivina  E. S.  Temraleeva  A. D. 《Microbiology》2020,89(6):720-732
Microbiology - The article considers the system of the Chlorella-clade based on morphological, ecological, and molecular genetic data. Diagnostic characteristics of some genera and species are...  相似文献   

17.
贵州蓑藓属一新种   总被引:2,自引:0,他引:2  
TherearespeciesofMacromitriuminGuizhouprovinceChina .Amongthem ,2speciesareen demicspecies ,M .cavalerierCard&Ther .andM .fortunatiiCard&Ther .Duringarecentre -examinationofsomeMacromitriumspecimensfromthisregion .AtaxoncloselyrelatedtospeciesoftheM .ferrieiCar…  相似文献   

18.
记述采自贵州省施秉县一洞穴小弱蛛属Leptonetela一新种,施秉小弱蛛Leptonetela shibingensis sp.nov.。该新种近似于查氏小弱蛛Leptonetela zhai WangLi,2011,主要区别有:眼退化,仅留眼丘,后者6眼完全;雄蛛触肢器中突(median apophysis,M)小,三角形,而后者中突大,近掌状;雄蛛触肢器胫节基刺(basal spine of male palpal tibia,TBS)短而粗,末端向内弯曲。模式标本保存于贵州科学院生物研究所。  相似文献   

19.
2018年5月,在贵州省黄平县朱家山县级自然保护区进行本底资源调查时采集到蛙属Rana物种标本10号,结合形态鉴定和分子系统学分析,确认该物种为徂徕林蛙Rana culaiensis,为贵州省两栖动物新记录。此次发现对于进一步认识徂徕林蛙的形态特征及地理分布格局具有重要意义。此次采集标本与模式产地标本在体型、趾间蹼等方面存在差异,这种差异是否为适应不同的地理环境而产生的形态变异,还有待采集符合统计学的标本数据来论证。  相似文献   

20.
A mating-type analysis was performed on 78 stocks of the marine hypotrich ciliate, Aspidisca sp., from a sufficient number of diverse geographic locations, some widely separated. Evidence is provided for the existence of a binary mating system in this "morphospecies." The collected stocks have been challenged by the most rigorous criterion, namely breeding affinity in the laboratory, and have yielded at least four reproductively, not necessarily geographically, isolated groups that are in fact "biological species," here referred to as "syngens." Different syngens contain different pairs of mating types. Syngens are morphologically indistinguishable; hence Aspidisca sp. can be considered a conservative taxon comprising a number of "cryptic" or "sibling species." Information is also presented about the mating behavior and the pattern of nuclear events at conjugation in Aspidisca sp. Search for soluble pheromones of the mating types gave only negative results. Hence, direct contact with potential partners is postulated to play a critical role in preparing individuals to mate. Mating reaction and mating which actually involves cross-fertilization (conjugation, sensu stricto) are completely inhibited by 10 μg/ml cycloheximide, suggesting the necessity of protein synthesis for recognition and union in conjugation of potential partners.  相似文献   

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