分子标志在蚊虫系统发育关系重建中的应用现状

分子标志是重建生物系统发育关系的关键。目前，在蚊虫研究中应用的分子标志主要包括两大类，即核基因和线粒体基因序列。该文综述了上述两类分子标志在蚊虫系统发育关系重建中的应用现状，核基因和线粒体基因相结合重建按蚊的系统发育关系具有较高的可信度。该文还介绍了建立在基因组计划基础上的全新学科——系统发育基因组学（phylogenomics）。该学科在解决一些生物进化的基本问题方面有巨大潜力。     

基于分子特征的白蛉系统发育研究现状

该文综述了基于分子特征的白蛉群体遗传结构、近缘种鉴别和系统发育关系重建的研究现状,列举了所应用的分子标志,依据研究内容选择适合的分子标志仍需进一步确定.     

海南岛按蚊的鉴定和迷走按蚊的进化研究

目的 阐明海南岛某些按蚊的分类地位,探讨迷走按蚊与其近缘种的亲缘关系. 方法 对采自海南岛8个地点的按蚊依据形态和分子特征进行鉴别研究,应用的分子特征包括核糖体DNA(ribosomal DNA,rDNA)第2内转录间隔区(second internal transcribed spacer,ITS2)和28S第3编码区(third domain,D3)序列,综合分析迷走按蚊及其近缘种的ITS2和D3序列,构建系统发育树. 结果 本研究共鉴定按蚊407只,其中84.9％的成蚊分子鉴定与依据形态鉴定的结果一致.在228条迷走按蚊的ITS2序列中,部分个体在2个位点存在单碱基套峰(G/A),出现的频率分别为57.9％、64.8％,同时有两个套峰的占样本数的57.0％,其他位点保守.迷走按蚊的D3序列,在种内无碱基差异.结合本研究和文献的迷走按蚊及其近缘种ITS2序列构建的ML树,显示迷走按蚊与浅色按蚊MC/D亲缘关系近,与另一支的浅色按蚊B、圣代克按蚊复合体的亲缘关系较远.关于未订名种NBC (Anophelessp.NBG)的分类地位,依据分子特征鉴定其为浅色按蚊B,可能是圣代克按蚊复合体新的成员种.结论 鉴定形态在个体间变异大的种类时,客观的分子特征更具重要性,迷走按蚊与浅色按蚊MC/D具较近的亲缘关系.     

RAPD技术及其在蚊分类鉴定中的应用

在蚊分类研究中，长期以来大多是以形态特征作为分类的依据，然而许多复合体的相继发现及亲缘种的存在，使得单纯的形态学方法难以对其进行鉴别。分子生物学的发展，为蚊分类提供了新的思路和新的方法并已开始应用于蚊分类研究，弥补了传统分类方法的不足，可进行更为精确的蚊分类。     

拟钉螺及其传播的血吸虫的种系发生

拟钉螺可作为多种亚洲血吸虫和并殖吸虫的中间宿主,对其分子系统发育的研究正逐渐深入.亚洲血吸虫的起源归属问题仍末得到解决,中华血吸虫的研究有望为其提供参考.该文从形态学、种群遗传学、分子生物学和生物地理学等4个方面阐述了拟钉螺亚科系统发育的研究进展,分析了中华血吸虫及其相关的亚洲血吸虫的研究现状,并就今后研究方向作出了展望.     

RAPD技术及其在蚊分类鉴定中的应用

在蚊分类研究中,长期以来大多是以形态特征作为分类的依据。然而许多复合体的相继发现及亲缘种的存在,使得单纯的形态学方法难以对其进行鉴别。分子生物学的发展,为蚊分类研究提供了新的思路和新的方法并已开始应用于蚊分类研究,弥补了传统分类方法的不足,可进行更为精确的蚊分类。随机引物扩增多态性DNA(RAPD)分析技术是90年代发展起来的一种以PCR为基础的DNA分析方法。本文介绍了该技术的原理、特点并综述了其在蚊分类中实际应用的一些例子。     

孟加拉国吉大港兰加马蒂蚊类群落特征调查

目的了解孟加拉国兰加马蒂蚊类种群群落特征,为当地媒介蚊虫控制措施的制定提供依据。方法 2019年9月,在孟加拉国兰加马蒂人房和牛房采用诱蚊灯通宵诱捕成蚊,形态鉴定蚊种并分析其群落特征。结果共捕获蚊虫2亚科7属33种6 445只,当地的优势蚊种为菲律宾按蚊和三带喙库蚊,分别占捕获蚊总数的37.66%(2 427/6 445)和35.67%(2 299/6 445)。人房致倦库蚊构成比较高,为73.59%(719/977);牛房菲律宾按蚊占41.73%(282/5 468),三带喙库蚊占41.04%(2 244/5 468)。蚊虫Shannon-Wienner多样性指数为1.62,Simpson多样性指数为0.29,Pielou均匀度指数0.46。结论孟加拉国兰加马蒂蚊虫种类丰富,疟疾和乙型脑炎媒介蚊虫属于当地优势蚊虫种群。应进一步加强孟加拉国蚊虫群落特征研究,为当地媒介蚊虫控制措施的制定提供参考依据。     

应用PCR RFLP鉴别非洲和亚洲的主要传疟媒介催命按蚊种团和微小按蚊种团

所有生物学特性的研究必须在其相应物种精确鉴定的基础上进行,尤其是在虫媒病研究中,正确和精确的物种鉴别具有重要的医学和现实意义。非洲的催命按蚊(A.funestus)和亚洲的微小按蚊亲缘关系很近,但地理分布存在隔离。催命按蚊种团由8种组成,除催命按蚊嗜吸人血、家栖,为高效的传疟媒介外,其他种类均嗜吸动物血;同样在亚洲,微小按蚊种团由9种组成,其中微小按蚊(广义)是当地主要的传疟媒介之一。由于催命按蚊和微小按蚊种团各自的成员种间形态极为相似,在现场工作中依据成蚊鉴别媒介和非媒介难免混淆。虽然依据分子标记已经分别建立了区分催…     

我国赫坎按蚊种团的分子鉴别及中华按蚊的区系分布研究

目的改进赫坎按蚊种团部分成员种的多重PCR鉴别方法,鉴别赫坎按蚊种团中的中华按蚊,研究我国中华按蚊的区系分布及其影响因素。方法依据赫坎按蚊种团成员种中华按蚊、八代按蚊、雷氏按蚊、比伦按蚊和克莱按蚊的核糖体DNA内转录间隔区2 (rDNA-ITS2)序列差异设计种特异引物,改进多重PCR分子鉴别方法。2013-2018年,在我国8个省(直辖市、自治区)共18个地点,以诱虫灯和人工吸取相结合的方法采集按蚊,依据形态特征初步鉴定为赫坎按蚊种团的成员种。提取单只蚊虫基因组DNA,使用改进的多重PCR方法鉴定种类。对多重PCR法无扩增产物的个体分析rDNA-ITS2序列,在GenBank上进行BLAST比对,确定其种类。查找我国以及韩国和俄罗斯远东地区用分子特征鉴别为中华按蚊的文献,结合本研究结果,汇总中华按蚊采集地的地理位置和气候数据,使用地理探测器模型计算影响决定力q值,分析经度、纬度、年平均气温和年平均降雨量对中华按蚊分布的影响。结果改进的多重PCR法一次扩增即可依据扩增片段大小鉴别赫坎按蚊种团的5个成员种:中华按蚊(490 bp)、雷氏按蚊(313 bp)、八代按蚊(216 bp)、克莱按蚊(386 bp)和比伦按蚊(165 bp)。在我国18个采集点共捕获赫坎按蚊种团按蚊365只,多重PCR鉴别为中华按蚊114只(来自陕西、安徽与山东的采集点)、八代按蚊34只、雷氏按蚊9只、克莱按蚊181只和比伦按蚊5只。22只多重PCR无扩增产物的蚊虫中,经rDNA-ITS2序列分析鉴定为贵阳按蚊2只、类中华按蚊1只、朝鲜按蚊8只、林氏按蚊7只和帕氏按蚊4只。获取用分子特征鉴别为中华按蚊的文献17篇,共汇总了101个采集地信息,其中有中华按蚊分布的采集点80个,无中华按蚊分布的21个地点。地理探测器软件计算获得的q值,从大到小依次为0.592 0(年平均气温)、0.507 2 (纬度)、0.351 2 (经度)和0.214 4 (年平均降雨量)。中华按蚊的分布与年平均气温关系最为密切,其次是纬度。综合分析分布地的纬度和年平均温度等结果显示,年平均气温10℃可以作为划分中华按蚊在我国分布北界线的依据。我国中华按蚊的分布范围包括云南、贵州、重庆、河南、山东、天津、江苏、安徽、湖北、浙江、上海、福建、江西、广西、广东、海南等省(直辖市、自治区)及台湾、香港、澳门特别行政区的全境,以及西藏、四川、甘肃、陕西、山西、河北、北京、辽宁等省(直辖市、自治区)的南部部分地区。结论改进的赫坎按蚊种团多重PCR分子鉴定方法快速简单、客观可靠。综合分析显示划分中华按蚊在我国分布北界线的依据是年平均气温10℃线,中华按蚊在我国的分布应小于之前记载的范围。     

我国昆明按蚊与凉山按蚊rDNA-ITS2序列和形态比较及分类地位的探讨

[目的 ]论证昆明按蚊 (Anopheles kunmingensis)和凉山按蚊 (An. liangshanensis)的分类地位。 [方法 ]比较两种按蚊 r DNA- ITS2序列差异和主要形态特征的变化幅度。 [结果 ]两种按蚊 8个样本 r DNA- ITS2序列同源性为 97.1%～ 99.8%。昆明按蚊雌蚊翅 V5 .2缘缨白斑、后跗 基白环 (斑 )及幼虫头毛 2 - C具叉枝等特征出现率分别为 43% (9/ 2 1)、 89% (17/ 19)及 40 % (4/ 10 ) ,而凉山按蚊则分别为 79% (34 / 43)、 44 % (17/ 39)及 2 0 % (4/ 2 0 ) ;如以不同群体作统计分析 ,各特征出现率波动幅度很大 ,交叉重叠 ;表明两蚊种间缺乏明确与稳定的鉴别特征 ,缺乏实质性的形态差异。 [结论 ]两种按蚊形态特征和分子序列差异极小 ,应属种内变异范围 ,可以确认两者是同一蚊种 ,昆明按蚊为凉山按蚊的同物异名。     

Molecular phylogeny of choanoflagellates, the sister group to Metazoa

Choanoflagellates are single-celled aquatic flagellates with a unique morphology consisting of a cell with a single flagellum surrounded by a "collar" of microvilli. They have long interested evolutionary biologists because of their striking resemblance to the collared cells (choanocytes) of sponges. Molecular phylogeny has confirmed a close relationship between choanoflagellates and Metazoa, and the first choanoflagellate genome sequence has recently been published. However, molecular phylogenetic studies within choanoflagellates are still extremely limited. Thus, little is known about choanoflagellate evolution or the exact nature of the relationship between choanoflagellates and Metazoa. We have sequenced four genes from a broad sampling of the morphological diversity of choanoflagellates including most species currently available in culture. Phylogenetic analyses of these sequences, alone and in combination, reject much of the traditional taxonomy of the group. The molecular data also strongly support choanoflagellate monophyly rejecting proposals that Metazoa were derived from a true choanoflagellate ancestor. Mapping of a complementary matrix of morphological and ecological traits onto the phylogeny allows a reinterpretation of choanoflagellate character evolution and predicts the nature of their last common ancestor.     

棘球属绦虫分子种系发生研究进展

棘球属绦虫引起的棘球蚴病是一种严重危害人和动物健康的人兽共患寄生虫病。棘球属绦虫分子种系发生分类研究的最新结果表明,其传统的形态学分类需要修正,从原有的5个种增加到9个种。特对棘球属绦虫分子种系发生研究新进展作一综述,为棘球蚴病的病原生物学鉴定和分类提供参考。     

MADS-box genes reveal that gnetophytes are more closely related to conifers than to flowering plants

The evolutionary origin of the angiosperms (flowering plants sensu stricto) is still enigmatic. Answers to the question of angiosperm origins are intimately connected to the identification of their sister group among extinct and extant taxa. Most phylogenetic analyses based on morphological data agree that among the groups of extant seed plants, the gnetophytes are the sister group of the angiosperms. According to this view, angiosperms and gnetophytes are the only extant members of a clade called "anthophytes" to emphasize their shared possession of flower-like reproductive structures. However, most phylogeny reconstructions based on molecular data so far did not support an anthophyte clade, but also could not clarify the case because support for alternative groupings has been weak or controversial. We have isolated 13 different homologs of MADS-type floral homeotic genes from the gnetophyte Gnetum gnemon. Five of these genes fall into monophyletic gene clades also comprising putatively orthologous genes from flowering plants and conifers, among them orthologs of floral homeotic B and C function genes. Within these clades the Gnetum genes always form distinct subclades together with the respective conifer genes, to the exclusion of the angiosperm genes. This provides strong molecular evidence for a sister-group relationship between gnetophytes and conifers, which is in contradiction to widely accepted interpretations of morphological data for almost a century. Our phylogeny reconstructions and the outcome of expression studies suggest that complex features such as flower-like reproductive structures and double-fertilization arose independently in gnetophytes and angiosperms.     

Morphometrics and hominoid phylogeny: Support for a chimpanzee-human clade and differentiation among great ape subspecies

Taxonomic and phylogenetic analyses of great apes and humans have identified two potential areas of conflict between molecular and morphological data: phylogenetic relationships among living species and differentiation of great ape subspecies. Here we address these problems by using morphometric data. Three-dimensional landmark data from the hominoid temporal bone effectively quantify the shape of a complex element of the skull. Phylogenetic analysis using distance-based methods corroborates the molecular consensus on African ape and human phylogeny, strongly supporting a Pan-Homo clade. Phenetic differentiation of great ape subspecies is pronounced, as suggested previously by mitochondrial DNA and some morphological studies. These results show that the hominoid temporal bone contains a strong phylogenetic signal and reveal the potential for geometric morphometric analysis to shed light on phylogenetic relationships.     

Replicated evolution of trophic specializations in an endemic cichlid fish lineage from Lake Tanganyika

The current phylogenetic hypothesis for the endemic Lake Tanganyika cichlid fishes of the tribe Eretmodini is based solely on morphology and suggests that more complex trophic morphologies derived only once from a less specialized ancestral condition. A molecular phylogeny of eretmodine cichlids based on partial mitochondrial DNA cytochrome b and control-region sequences was used to reconstruct the evolutionary sequence of trophic adaptations and to test alternative models of morphological divergence. The six mitochondrial lineages found disagree with the current taxonomy and the morphology-based phylogeny. Mitochondrial lineages with similar trophic morphologies are not grouped monophyletically but are typically more closely related to lineages with different trophic phenotypes currently assigned to other genera. Our results indicate multiple independent origins of similar trophic specializations in these cichlids. A pattern of repeated divergent morphological evolution becomes apparent when the phylogeography of the mitochondrial haplotypes is analyzed in the context of the geological and paleoclimatological history of Lake Tanganyika. In more than one instance within Lake Tanganyika, similar morphological divergence of dentitional traits occurred in sympatric species pairs. Possibly, resource-based divergent selective regimes led to resource partitioning and brought about similar trophic morphologies independently and repeatedly.     

The Sahara as a vicariant agent,and the role of Miocene climatic events,in the diversification of the mammalian order Macroscelidea (elephant shrews)

Although the Sahara is a major geographical feature of the African continent, its role in the diversification of animal species is not well understood. We present here a molecular phylogeny for members of the endemic African mammalian order Macroscelidea (elephant shrews) with molecular-clock calculations; this molecular phylogeny provides convincing evidence that the genus Elephantulus is diphyletic. Elephantulus rozeti, the only elephant shrew species that resides north of the Sahara, is the sister group of a species from a different genus (Petrodromus tetradactylus), which resides just south of the Sahara. The split between these taxa coincided with major Miocene climatic events, which triggered the cooling and aridification of midlatitude continental regions, and a shift in the Sahara from a tropical to an arid environment. Thus, the North African distribution of E. rozeti is not the result of dispersion from an eastern species of the genus, but instead the result of a vicariant event involving the formation of the Sahara. The splitting events involved with most Elephantulus species in our analysis appear to coincide with these climatic events. This coincidence suggests that the environmental consequences associated with this period played an important role in the radiation of this order of mammals. The strongly supported phylogeny provides compelling evidence for a complex history of mosaic evolution, including pronounced bradytelic morphological evolution in some lineages, accelerated morphological evolution in others, and a remarkably slow rate of evolution of the male reproductive structure.     

Does behavior reflect phylogeny in swiftlets (Aves: Apodidae)? A test using cytochrome b mitochondrial DNA sequences.

Swiftlets are small insectivorous birds, many of which nest in caves and are known to echolocate. Due to a lack of distinguishing morphological characters, the taxonomy of swiftlets is primarily based on the presence or absence of echolocating ability, together with nest characters. To test the reliability of these behavioral characters, we constructed an independent phylogeny using cytochrome b mitochondrial DNA sequences from swiftlets and their relatives. This phylogeny is broadly consistent with the higher classification of swifts but does not support the monophyly of swiftlets. Echolocating swiftlets (Aerodramus) and the nonecholocating "giant swiftlet" (Hydrochous gigas) group together, but the remaining nonecholocating swiftlets belonging to Collocalia are not sister taxa to these swiftlets. While echolocation may be a synapomorphy of Aerodramus (perhaps secondarily lost in Hydrochous), no character of Aerodramus nests showed a statistically significant fit to the molecular phylogeny, indicating that nest characters are not phylogenetically reliable in this group.     

Phylogeny of hard- and soft-tick taxa (Acari: Ixodida) based on mitochondrial 16S rDNA sequences.

Ticks are parasitiform mites that are obligate hematophagous ectoparasites of amphibians, reptiles, birds, and mammals. A phylogeny for tick families, subfamilies, and genera has been described based on morphological characters, life histories, and host associations. To test the existing phylogeny, we sequenced approximately 460 bp from the 3' end of the mitochondrial 16S rRNA gene (rDNA) in 36 hard- and soft-tick species; a mesostigmatid mite, Dermanyssus gallinae, was used as an outgroup. Phylogenies derived using distance, maximum-parsimony, or maximum-likelihood methods were congruent. The existing phylogeny was largely supported with four exceptions. In hard ticks (Ixodidae), members of Haemaphysalinae were monophyletic with the primitive Amblyomminae and members of Hyalomminae grouped within the Rhipicephalinae. In soft ticks (Argasidae), the derived phylogeny failed to support a monophyletic relationship among members of Ornithodorinae and supported placement of Argasinae as basal to the Ixodidae, suggesting that hard ticks may have originated from an Argas-like ancestor. Because most Argas species are obligate bird octoparasites, this result supports earlier suggestions that hard ticks did not evolve until the late Cretaceous.     

The position of Hippopotamidae within Cetartiodactyla

The origin of late Neogene Hippopotamidae (Artiodactyla) involves one of the most serious conflicts between comparative anatomy and molecular biology: is Artiodactyla paraphyletic? Molecular comparisons indicate that Cetacea should be the modern sister group of hippos. This finding implies the existence of a fossil lineage linking cetaceans (first known in the early Eocene) to hippos (first known in the middle Miocene). The relationships of hippos within Artiodactyla are challenging, and the immediate affinities of Hippopotamidae have been studied by biologists for almost two centuries without resolution. Here, we compare opposing hypotheses implicating several “suiform” families. This morphological analysis of a comprehensive set of taxa and characters offers a robust solution to the origins of Hippopotamidae. This family appears to be deeply nested within the otherwise extinct artiodactyl family Anthracotheriidae, most precisely within the most advanced selenodont forms. The proposed sister group of hippos is the middle to late Miocene African semiaquatic Libycosaurus. Any close relationships of hippos with suoids, particularly with Tayassuidae, are rejected. Furthermore, the clade (Hippopotamidae, Anthracotheriidae) is proposed as the sister group of the Cetacea, offering broad morphological support for a molecular phylogeny, such support being also consistent with the fossil record. Corroboration of this relationship requires an exploration of anthracothere affinities with other Paleogene artiodactyls. Among those, the position of Ruminantia is a central question, still to be solved. Further progress in this debate is likely to come from morphological studies of paleontological data, whether known or still to be discovered.