植物分子系统地理学及其研究进展

系统地理学这个概念框架来源于早期对线粒体DNA(mitochondrial DNA,mtDNA)的研究。随着系统地理学研究方法的不断拓展和分子生物学实验技术的渗透,出出了一门新的交叉学科——分子系统地理学(Mokcular phylogeography)。本文简述了分子系统地理学的发展简史和植物分子系统地理学研究常用的分子标记,回顾了近年来植物分子系统地理学方面的研究进展以及存植物研究中的应用。并对植物分子系统地理学研究进行了展望。     

松鼠分子生态学研究进展

松鼠由于受到非法猎捕、栖息地破坏及欧洲部分地区的北美灰松鼠生态入侵,导致种群数量锐减,现已被世界自然保护联盟(IUCN)列为近危种,我国吉林省已将其列入省重点保护野生动物名录.分子生物学研究方法的快速发展,尤其是基于mtDNA片段开展的相关研究,以及已筛选出并能应用于松鼠研究的微卫星位点的应用,使松鼠分子生态学研究不断深入.本文对松鼠的分子系统发育、遗传多样性和分子系统地理学等分子生态学内容进行了综述,并提出松鼠分子生态学未来研究的展望:进一步探讨松鼠与日本松鼠的系统分化关系;松鼠连续种群、隔离种群和集合种群的遗传多样性比较分析;利用核基因其他标记分析松鼠分子系统地理学问题;探讨亚洲是否存在第四纪冰期避难所.     

啮齿动物巢区研究进展

巢区 (ｈｏｍｅｒａｎｇｅ)这一术语为生物学家们所使用是从 190 9年Ｓｅｌｔｏｎ开始的 ,直到 194 0年才由Ｂｕｒｔ定义为 :巢区是动物在其巢附近进行取食、生殖、育幼等日常活动的区域[54 ] 。此后 ,这一概念几乎没有争议 ,只是有些学者在与领域概念的使用上未加严格区分 ,而多数学者强调领域只是巢区中不允许同种其它个体侵入而受到严格保护的核心部分[2 ] 。近年Ｂｏｎｄ等[19] 提出最适巢区概念 ,为深入分析鼠类繁殖策略、进化及其巢区生态学功能提供了新思路 ,已成为巢区研究的一个重要方向。绝大多数啮齿动物营穴居生活 ,巢区研究对…     

杜鹃花科白珠树属分子系统学和生物地理学研究进展

白珠树属(Gaultheria)在杜鹃花科(Ericaceae)系统演化中占有十分重要的地位,其系统位置和演化关系一直备受争议.最近的分子系统学研究认为,白珠树属已经不再属于传统上的越橘亚科(Vaccinioideae)的綟木族(Andromedeae),而是与一些相关属组成了白珠树族(Gaultherieae).对白珠树属产于美洲的类群和相关类群的分子系统学的初步研究则表明,该属与Diplycosia、Tepuia和Pernettya等属(均为"常绿类群")关系密切,可能应将这几个属并入到白珠树属中,但其属下分类系统关系还需要对产于亚洲的类群进行深入的研究后才能确定.白珠树属与其近缘属的进化历史和生物地理学关系较为复杂,与杜鹃花科其他大多数属不同,白珠树属为典型的环太平洋分布.关于白珠树属的起源问题存在两种不同的推测:一种观点认为该属起源于南半球的冈瓦纳古陆;另一种观点则认为其起源于北半球的劳亚古大陆.本文概述了近年来白珠树属的分子系统学和生物地理学研究进展,并对该属尚存的一些问题进行了讨论.     

杜鹃花科白珠树属分子系统学和生物地理学研究进展

白珠树属(Gaultheria) 在杜鹃花科(Ericaceae)系统演化中占有十分重要的地位, 其系统位置和演化关系一直备受争议。最近的分子系统学研究认为, 白珠树属已经不再属于传统上的越橘亚科(Vaccinioideae)的綟木族(Andromedeae), 而是与一些相关属组成了白珠树族(Gaultherieae)。对白珠树属产于美洲的类群和相关类群的分子系统学的初步研究则表明, 该属与Diplycosia、Tepuia和Pernettya等属(均为“常绿类群”)关系密切, 可能应将这几个属并入到白珠树属中, 但其属下分类系统关系还需要对产于亚洲的类群进行深入的研究后才能确定。白珠树属与其近缘属的进化历史和生物地理学关系较为复杂, 与杜鹃花科其他大多数属不同, 白珠树属为典型的环太平洋分布。关于白珠树属的起源问题存在两种不同的推测: 一种观点认为该属起源于南半球的冈瓦纳古陆; 另一种观点则认为其起源于北半球的劳亚古大陆。本文概述了近年来白珠树属的分子系统学和生物地理学研究进展, 并对该属尚存的一些问题进行了讨论。     

啮齿动物的嗅觉通讯研究进展

通过对近40 年来啮齿动物嗅觉通讯的研究综述, 主要介绍嗅觉信号的来源、组成及其对啮齿动物行为生理所产生的作用。啮齿动物嗅觉通讯的信号来源主要是粪便、尿液和特化皮肤腺等, 对这些化学信号的成分分析主要集中在各种信息素(Pheromone) 的结构、来源及其引起的行为反应。目前, 在对啮齿动物嗅觉通讯神经通路的研究中, 对主嗅觉系统和犁鼻器系统在动物嗅觉通讯中的作用仍将是人们研究的重点; 而通过信息素作用所产生的各种行为反应的神经内分泌机制也是动物嗅觉通讯领域研究的热点之一。研究气味信号对动物行为和生理等方面所产生的作用, 将有助于揭示啮齿动物嗅觉通讯在其社会行为中的重要作用。     

类风湿性关节炎啮齿动物模型的研究进展

类风湿性关节炎是一种常见的致残性疾病之一,病因未明。研究此类疾病的有效方法是建立、研究并应用动物模型。通过对目前国内外类风湿性关节炎模型复制方法、机制和应用的研究,分析各自的特点及不足之处,提出复制更加符合类风湿性关节炎临床特点的动物模型的展望与设想。     

地下啮齿动物视觉系统的形态结构与机能进化

感觉系统的适应进化机制一直是动物行为学研究的焦点。生活在特殊环境中的动物,其感觉系统在进化过程中表现出的显著差异更是引人注目。由于适应地下黑暗生活环境,地下啮齿动物感觉系统在各个组织水平都表现出进化和退化镶嵌的形态特征,其视觉系统表现得最为突出：视觉器官退化,有关图象分析结构、由视觉诱导产生行为反应的脑区及视觉投射严重退化,有关感受光周期的“非成像” 视觉通路结构高度发达。本文综述了地下啮齿动物视觉系统的结构、功能、进化与发育等方面的研究进展,旨在阐明地下啮齿动物视觉系统的特点,有助于开展地下啮齿动物视觉系统适应进化机制的研究。     

历史生物地理学的进展

近年来历史生物地理学的进展主要是隔离分化学派的进展。对隔离分化学派的几个分支学派,特别是分支生物地理学和泛生物地理学在理论和方法方面的进展作了简要回顾和介绍。最近十年来分子手段广泛应用于历史生物地理学研究的各个方面,尤其是谱系生物地理学的快速崛起是历史生物地理学的一个明显特征。对本学科的发展做了初步的展望。     

Phylogeographical structure in the subterranean tuco-tuco Ctenomys talarum (Rodentia: Ctenomyidae): contrasting the demographic consequences of regional and habitat-specific histories

In this work we examined the phylogeography of the South American subterranean herbivorous rodent Ctenomys talarum (Talas tuco-tuco) using mitochondrial DNA (mtDNA) control region (D-loop) sequences, and we assessed the geographical genetic structure of this species in comparison with that of subterranean Ctenomys australis, which we have shown previously to be parapatric to C. talarum and to also live in a coastal sand dune habitat. A significant apportionment of the genetic variance among regional groups indicated that putative geographical barriers, such as rivers, substantially affected the pattern of genetic structure in C. talarum. Furthermore, genetic differentiation is consistent with a simple model of isolation by distance, possibly evidencing equilibrium between gene flow and local genetic drift. In contrast, C. australis showed limited hierarchical partitioning of genetic variation and departed from an isolation-by-distance pattern. Mismatch distributions and tests of neutrality suggest contrasting histories of these two species: C. talarum appears to be characterized by demographic stability and no significant departures from neutrality, whereas C. australis has undergone a recent demographic expansion and/or departures from strict neutrality in its mtDNA.     

Molecular Relationships Among Octodontidae (Mammalia: Rodentia: Caviomorpha)

We examined ten species of octodontid rodents and representatives of three outgroups in a complete 13 × 13 DNA-hybridization matrix. The results were indexed as differences in median melting-point depressions (T,_ms), symmetrized, subjected to phylogenetic analysis using FITCH, bootstrapped, and exhaustively taxon-jackknifed. Within Octodontidae, four clades were recovered with 100% bootstrap and complete jackknife support: Tympanoctomys barrerae with Octomys mimax, Octodontomys gliroides alone, Octodon spp., and Aconaemys spp. with Spalacopus cyanus; the latter two clades were closer to each other than either was to Octodontomys or Octomys-Tympanoctomys, but were slightly nearer to and united with Octodontomys, with 89% bootstrap support. However, relationships among the three Aconaemys species and Spalacopus were not completely resolved by our experiments. Ctenomys coyhaiquensis, Abrocoma bennetti, and Lagostomus maximus represented successive outgroups to Octodontidae, while one-way comparisons with Cavia porcellus and Microcavia australis suggested that these caviids are almost as distant from octodontoids as is the chinchilloid Lagostomus. When the data were suitably corrected for percentage hybridization and saturation, division of the distances by the rate previously determined for most amniotes (0.48%/myr) suggested that the basal divergence among the caviomorph rodents examined occurred about 59 myrbp, and that Octodontidae originated 40 myrbp and diversified into extant lineages beginning 14 myr ago. Calibration against the date of the earliest known caviomorph (late Eocene or about 37.5 myrbp) gave a rate of 0.75%/myr, which would suggest later dates for subsequent caviomorph cladogenesis. It is notable that, based respectively on the slower or faster rates, the tetraploid Tympanoctomys barrerae must have diverged from its sister-taxon Octomys mimax 10 or 6.5 myr ago.     

Transalpine colonisation and partial phylogeographic erosion by dispersal in the common vole (Microtus arvalis)

The colonisation history and genetic structure of the common vole ( Microtus arvalis ) was investigated in the region of the Alps by analysing the mitochondrial cytochrome b gene (mtDNA) and 19 microsatellite loci (nucDNA) for 137 voles from 52 localities. mtDNA data provided a much refined distribution of three highly divergent evolutionary lineages in the region compared to previous studies. Although high mountain ranges are widely accepted to be barriers for colonisation processes for many organisms and especially small terrestrial mammals, our phylogeographic analyses showed clear evidence of four transalpine colonisation events by the common vole. Individual-based phylogenetic analyses of nucDNA and two alternative Bayesian-clustering approaches revealed a deep genetic structure analogous to mtDNA. Incongruence between nucDNA and mtDNA at the individual level was restricted to the regions of contact between the lineages. mtDNA patterns and strong female philopatry in M. arvalis suggest that the crossings of the Alps occurred during the colonisation of the region when it was free from ice after the last glaciation. nucDNA patterns suggest that some of the transalpine elements of this phylogeographic pattern were subsequently eroded by male-biased gene flow. We conclude that the combination of phylogeography and landscape genetics at the individual level can provide very detailed insights into colonisation events and may even allow differentiation between historical and more recent processes.     

Comparative phylogeography of unglaciated eastern North America

Regional phylogeographical studies involving co-distributed animal and plant species have been conducted for several areas, most notably for Europe and the Pacific Northwest of North America. Until recently, phylogeographical studies in unglaciated eastern North America have been largely limited to animals. As more studies emerge for diverse lineages (including plants), it seems timely to assess the phylogeography across this region: (i) comparing and contrasting the patterns seen in plants and animals; (ii) assessing the extent of pseudocongruence; and (iii) discussing the potential applications of regional phylogeography to issues in ecology, such as response to climatic change. Unglaciated eastern North America is a large, geologically and topographically complex area with the species examined having diverse distributions. Nonetheless, some recurrent patterns emerge: (i) maritime - Atlantic vs. Gulf Coast; (ii) Apalachicola River discontinuity; (iii) Tombigbee River discontinuity; (iv) the Appalachian Mountain discontinuity; (v) the Mississippi River discontinuity; and (vi) the Apalachicola River and Mississippi River discontinuities. Although initially documented in animals, most of these patterns are also apparent in plants, providing support for phylogeographical generalizations. These patterns may generally be attributable to isolation and differentiation during Pleistocene glaciation, but in some cases may be older (Pliocene). Molecular studies sometimes agree with longstanding hypotheses of glacial refugia, but also suggest additional possible refugia, such as the southern Appalachian Mountains and areas close to the Laurentide Ice Sheet. Many species exhibit distinct patterns that reflect the unique, rather than the shared, aspects of species' phylogeographical histories. Furthermore, similar modern phylogeographical patterns can result from different underlying causal factors operating at different times (i.e. pseudocongruence). One underemphasized component of pseudocongruence may result from the efforts of researchers to categorize patterns visually - similar patterns may, in fact, not fully coincide, and inferring agreement may obscure the actual patterns and lead to erroneous conclusions. Our modelling analyses indicate no clear spatial patterning and support the hypothesis that phylogeographical structure in diverse temperate taxa is complex and was not shaped by just a few barriers.     

Molecular detection of Bartonella species infecting rodents in Slovenia

Rodents, collected in three zoogeographical regions across Slovenia, were tested for the presence of bartonellae using direct PCR-based amplification of 16S/23S rRNA gene intergenic spacer region (ITS) fragments from splenic DNA extracts. Bartonella DNA was detected in four species of rodents, Apodemus flavicollis, Apodemus sylvaticus, Apodemus agrarius and Clethrionomys glareolus, in all three zoogeographic regions at an overall prevalence of 40.4%. The prevalence of infection varied significantly between rodent species and zoogeographical regions. Comparison of ITS sequences obtained from bartonellae revealed six sequence variants. Four of these matched the ITS sequences of the previously recognized species, Bartonella taylorii, Bartonella grahamii, Bartonella doshiae and Bartonella birtlesii, but one was new. The identity of the bartonellae from which the novel ITS sequences was obtained were further assessed by sequence analysis of cell division protein-encoding gene (ftsZ) fragments. This analysis demonstrated that the strain is most likely a representative of possible new species within the genus.     

分子系统地理学及其应用

分子系统地理学是20世纪70年代中期伴随着对线粒体DNA的认识而开始酝酿发展的,本文回顾了该学科自诞生以来的发展简史,阐述了其研究内容,着重从3个方面介绍了该领域在其它相关学科中的研究进展,总结了该学科存在的问题,并提出重点应解决的3个问题：1）将细胞器基因与遗传信息更为丰富的核基因相结合;2）合生理论在非平衡种群中的发展应用;3）提高对分化时间估计的精确性。     

分子生物学技术在昆虫系统发育地理学研究中的应用

文章对分子生物学技术在系统发育地理学上的应用和研究进展进行综述。介绍mtDNA和ITS等使用最频繁的分子标记,其研究方法最好是测序加上RAPD,RFLP分析,同工酶电泳,SSCP和DSCP中的1种以上或几种方法的组合,数据分析最好是2种方法共同使用,从而确保结果的准确性。     

生物冰期避难所与冰期后的重新扩散

冰期（尤其是更新世冰期）对当今生物的空间分布格局和遗传结构产生了深远影响,研究生物冰期避难所对于了解不同生物区系间的关系、物种形成以及生物多样性保护具有十分重要的意义。生物冰期避难所的确定员韧是根据特有种的分布、化石、抱粉等证据推测而来,分子遗传标记为冰期生物避难所以及冰期后重新扩散路线的研究提供了有力的工具。本文以北美和欧洲为例,介绍了分子遗传标记在生物避难所以及冰期后再扩散路线研究中的应用和一些结论。我国存在许多东西走向的大山,减缓了冰期时低温对生物的影响,为许多生物提供了避难场所,但我国有关研究开展得很少。员后,对我国该领域提出了应优先开展的研究方向。