中国栅蛛属2新种记述(蜘蛛目:栅蛛科)

本文记了分别采自云南高黎贡山的栅蛛科栅蛛属Hahnia 2新种:垭口栅蛛,新种S.yakouensis sp.nov.和肾形栅蛛,新种S.reniformis sp.nov..垭口栅蛛后眼列前曲,交媾腔大,扁圆形,交媾孔1个,位于交媾腔下缘,交媾管粗,呈"人"字形下行分成2支再向两侧扭曲.纳精囊有一肓管斜向上伸出,鉴于上述特征而与Hahnia mridulae Tikader,1970不同.肾形栅蛛交媾孔2个,位于生殖厣腹面中央,纳精囊1对,大,肾形,插入器始于生殖球左下方,鉴于上述特征而与Hahnia xinjiangensis Wang et Liang,1989不同. Abstract： The present paper deals with two new species of the genus Hahnia collected from the Gaoligong Mountains Region of Yunnan Province, China: Hahnia yakouensis sp. nov., Hahnia reniformis sp. nov..     

注重发挥博士后科研生力军作用

中国医科大学博士后科研流动站始建1995年。目前学校设有基础医学、临床医学和生物学3个博士后科研流动站。但由于每年国家财力有限,资助名额很少,在有限条件下建立、健全博士后制度,加强对博士后人员的培养,调动博士后人员的积极性是一项重要的研究课题。     

遗传物质的发现者之一——麦卡锡

1944年,3位科学家艾弗里、麦卡锡和麦克劳德在DNA遗传本质方面的发现是20世纪最重要的发现之一,这个发现打开了生物学革命的大门,从而改变了人类对自然界的看法,这项研究还为1953年沃森和克里克DNA双螺旋结构的发现奠定了坚实的基础,但不幸的是3位科学家都未曾荣获诺贝尔奖.通过介绍麦克林·麦卡锡的科学研究,从而对这项发现的基本状况有一个基本的了解.     

生命之树与进化模式:导言

One and half centuries ago, Charles Darwin (1859) presented overwhelming evidence and argued that all life on the earth shared common descent, and "from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved". Ernst Haeckel (1886) and several of his contemporaries attempted to trace the pattern of descent among all extant and extinct forms in what Darwin referred to as "the great Tree of Life". Ever since then, systematists and evolutionary biologists have been exploring morphological, cytogenetic, chemical, developmental and molecular characters, and actively developing theories and methods to infer phylogenetic relationships among organisms from these characters. This endeavor has been especially stimulated by the rise of molecular biology and the emergence of computer science over the past 50 years. At the beginning of the 21st century, we are presented with an unprecedented opportunity to reconstruct the entire Tree of Life, and further, to study evolutionary processes and mechanisms in the context of a robust phylogenetic framework.     

我国微生态学的奠基人——魏曦

魏曦,字东升,1903年12月25日出生于湖南岳阳一个小职员家庭,父亲任职于邮政局.1914～1921年他在家乡湖滨中学读书,毕业后考入长沙湘雅医学院,学习两年后曾参加北伐军,任第四集团军警卫团三等军医.后退出军队,在长沙广雅中学任教.1928年入设立在上海的中央大学医学院(1932年独立为上海医学院)学习,1933年毕业,获博士学位.     

高黎贡山北段东西坡种子植物区系的比较研究

高黎贡山北段的东西坡由于在降雨量和热量分配等方面存在着显著的差异,致使东西坡在植物的种类、组成及区系特征等方面表现出明显的差异.东坡记载野生种子植物152科,580属,1475种及192变种(亚种),西坡记载野生种子植物162科,659属,1804种及186变种(亚种).东西坡种子植物科、属、种的对比分析表明:1)东西坡现代种子植物区系具有相同的历史渊源,但其区系联系减弱了,东西坡区系相似性程度,依科、属、种的顺序依次递减;2)西坡现代种子植物区系比东坡具有更为深刻的热带起源烙印.就科、属、种三个水平来说,东坡的热带成分低于西坡,温带成分高于西坡.许多典型的泛热带大科在西坡比东坡有着更为丰富的种类,其中有些泛热带科分子在东坡缺乏分布,而在西坡找到了合适的驻留之地;3)西坡现代种子植物区系与东喜马拉雅植物区系的联系比东坡紧密,而东坡与高黎贡山以东的区系联系比西坡密切,由于高黎贡山山脉的阻隔,近代植物物种的东西坡交流发生了障碍;4)西坡生态地理环境比东坡更有利于物种的生存、繁衍和分化,它既是古老成分的避难所,又是孕育新生成分的摇篮.     

用叶绿体ndhF和核核糖体ITS序列推断李属(蔷薇科)的系统发育

Sequences of the chloroplast ndhF gene and the nuclear ribosomal ITS regions are employed to reconstruct the phylogeny of Prunus (Rosaceae), and evaluate the classification schemes of this genus. The two data sets are congruent in that the genera Prunus s.l. and Maddenia form a monophyletic group, with Maddenia nested within Prunus. However, the ndhF data set is incongruent with the ITS data supporting two major groups within Prunus one consisting of subgenera Laurocerasus (including Pygeum) and Padus as well as the genus Maddenia and another of subgenera Amygdalus, Cerasus, and Prunus. The ITS data, on the other hand, support a clade composed of subgenera Amygdalus and Prunus and Prunus sect. Microcerasus in addition to a paraphyletic grade of subgenera Laurocerasus and Padus (and the genus Maddenia) taxa. In general, the subgeneric classifications of Prunus s.l. are not supported. The ITS and ndhF phylogenies differ mainly in interspecific relationships and the relative position of the Padus/Laurocerasus group. Both ITS and ndhF data sets suggest that the formerly recognized genus Pygeum is polyphyletic and that the distinction of the subgenera Padus and Laurocerasus is not supported. The biogeographic interactions of the temperate and tropical members in the Padus/Laurocera- sus/Maddenia alliance including Pygeum are shown to be highly dynamic and complex.     

鸡的瞬膜

瞬膜(nictitating membrane),又称第三眼睑,是一种保护眼球、防止灰尘的结构.鸟类的瞬膜位于眼眶的前眼角,为半透明的膜,其内缘具有一种羽毛上皮,借以刷洗角膜上的灰尘.在飞行时能遮覆眼球,以避免干燥气流和灰尘对眼球的伤害.由于瞬膜在鸟类睁眼的一瞬间迅速缩回前眼角,很难拍摄到.最近费了好大的周折,终于拍到了理想的鸡瞬膜照片,现予以发表供生物学界的同行共享(友情提示:如引用请注明原作者).     

途经甘肃的3种水鸟新纪录

2007年10月13日至11月5日进行敦煌市湿地鸟类调查时,分别在南湖湿地与候鸟自然保护区及党河水库使用Leica apo77高倍望远镜观察到3种水鸟,在以往的文献资料中未见其分布于甘肃的报道,应为甘肃鸟类新纪录。笔者用500mm镜头分别拍下3种水鸟的照片。1.赤颈(Podiceps grisegena)2007年10月13日13:30时,在南湖湿地与候鸟自然保护区的阳关水库(渥洼池)记录到2只赤颈。当时水面上同时有凤头(P.cristatus)、黑颈(P.nigricollis)以及大量鸭类、潜鸭类游禽活动,赤颈体形较凤头小,而又明显比黑颈大。其中一只赤颈的…     

中国东北地区远东鼩鼱遗传多样性与遗传结构

对中国东北地区3个种群(大兴安岭、小兴安岭和长白山山脉)的远东鼩鼱(77个样本)Cyt b基因全序列进行分析,共获得64个单倍型。整体单倍型多态性为0.9920,核苷酸多态性为0.0105,表明该地区远东鼩鼱具有较高遗传多样性,且长白山山脉远东鼩鼱种群遗传多样性明显高于大兴安岭和小兴安岭种群。F-统计量、遗传相似系数和遗传距离分析结果均显示,种群间和采样地间的遗传距离与地理距离基本相符。方差分析显示,种群间的变异占总变异的33.4%,种群内的采样地间变异占总变异的10.2%,采样点内部变异占总变异的56.4%。种群历史分析显示,东北地区远东鼩鼱未经历过数量扩张。从GenBank下载了欧亚其他地区远东鼩鼱序列进行遗传结构研究。远东鼩鼱系统发生树分化为2大分支:一大支主要由大兴安岭和小兴安岭种群构成,两种群具有一定分化;另一大支又分为两个分支。中介网络图显示,远东鼩鼱具有3个谱系:一个谱系主要由大兴安岭和小兴安岭的单倍型样本构成,还包括长白山山脉的4个单倍型样本;另一谱系包括来自于中国东北地区3个种群的个别单倍型,还包括俄罗斯贝加尔湖单倍型和芬兰单倍型;最后一个谱系完全是由长白山山脉单倍型构成。遗传多样性、系统发生树和中介网络图结果均表明,长白山山脉为远东鼩鼱末次冰期避难所。     

大石鸡兰州亚种的mtDNA种群遗传结构、单倍型分布和遗传多样性

大石鸡(Alectorismagna)是中国西北部的特有种。我们测定了大石鸡兰州亚种(A.m.lanzhouensis)8个地理种群106个样本的线粒体DNA控制区5′端458bp序列,研究其种群遗传结构和遗传多样性。27个变异位点共确定25种单倍型,其中单倍型M2广泛分布,而许多单倍型为一些地方种群特有。单倍型分布沿着南北方向变化,存在明显的地理结构。8个种群中核苷酸多样性最高的是定西种群,0.0069,最低的是海原种群,0.0028;单倍型多样性最高的是武山种群,0.86,最低的是北道种群,0.52。北方种群比南方种群具有更高的遗传多样性。系统发生树和单倍型分布表明,大石鸡兰州亚种存在两个明显的分支。溯祖理论、更新世冰期和花粉支持兰州亚种起源于兰州盆地,这个盆地是其遗传多样性的中心。     

中国圈养梅花鹿的遗传多样性和遗传结构

东北梅花鹿(Cervus nippon hortulorum)的野生种群已濒临灭绝,但其圈养种群遍布全国各地,是我国圈养梅花鹿的主要品种(亚种)。为了探讨圈养梅花鹿种群作为东北梅花鹿野外放归项目资源种群的可行性,测定了来自9个圈养种群45只梅花鹿个体的线粒体DNA控制区的部分序列,以此分析我国圈养梅花鹿种群的遗传多样性和遗传结构。结果表明,我国圈养梅花鹿种群的遗传多样性并不贫乏,种群之间并没有发生显著的遗传分化。因此,东北地区的圈养梅花鹿种群可以作为野外放归项目的资源种群,而野外放归项目的建群者应来源于东北地区的多个圈养种群。     

Genetic structure and phylogeography of a relict tree fern,Sphaeropteris brunoniana (Cyatheaceae) from China and Laos inferred from cpDNA sequence variations: Implications for conservation

In this study, we analyzed the genetic structure and phylogeography of Sphaeropteris brunoniana from China and Laos. Combining cpDNA trnL-trnF and atpB-rbcL sequence variations, five haplotypes were identified from the 10 investigated populations. Moderate haplotype diversity (h= 0.66580) and low nucleotide diversity (π= 0.23 × 10⁻³) were detected. The S. brunoniana in Yunnan region had much higher genetic diversity (h= 0.60195, π= 0.35 × 10⁻³) than that of Hainan–Laos (h= 0.00000, π= 0.00). A high level of genetic differentiation (94.74%) between the two regions was revealed by amova. Nested clade analysis identified two major clusters of the five haplotypes, one clade in the Yunnan region and the other in Hainan–Laos. The analysis indicated that restricted gene flow with isolation by distance and allopatric fragmentation were likely the major processes that shaped the spatial distribution of the haplotypes. The isolated distribution of clades implied the emergence of independent refugia of this species in each region during Quaternary glaciations. The Yunnan populations frequently contained an ancestral haplotype, and most of them harbored other descendent haplotypes. Based on the distribution pattern of haplotypes and the nested clade analysis results, the Yunnan region potentially had several refugia of this species during glacial periods, whereas the Hainan populations were probable new colonizations.     

东北亚地区野猪种群mtDNA遗传结构及系统地理发生

研究测定了中国东北、华北及四川西部72个野猪(Susscrofa)个体线粒体控制区全序列,并结合GenBank报道的日本野猪(S.s.leucomystax)、琉球野猪(S.s.riukiuanus)72个同源区序列,分析了东北亚地区野猪线粒体DNA的变异及系统地理格局。在东北亚地区野猪的线粒体控制区共发现42个变异位点,均为转换,共定义了34个单元型。单元型之间的系统发生分析表明,东北亚地区野猪来自同一祖先。东北亚地区野猪现生种群具有显著的种群遗传结构,其中日本野猪与分布于中国东北地区的东北野猪之间亲缘关系较近;而琉球野猪则与华北野猪间亲缘关系较近,与日本野猪和东北野猪间的关系相对较远。嵌套进化枝系统地理分析(Nestedcladephylogeographicalanalysis,NCPA)表明:东北亚地区野猪由同一祖先经过长距离的迁徙而形成现生各种群(或亚种);琉球野猪应起源于大陆野猪,其种群演化可能经历了片断化事件;华北野猪呈现南部种群遗传多样性高的特点,其种群内部曾经历了一次分布区由南向北的扩张     

中国狼不同地理种群遗传多样性及系统进化分析

为了解中国狼不同地理种群遗传多样性及系统发育情况,从中国境内狼的主要分布区青海、新疆、内蒙古和吉林4个地区采集样品,用分子生物学技术手段成功地获得44个个体线粒体DNA控制区第一高变区(HVRⅠ)序列和40个线粒体Cyt b部分序列。线粒体控制区HVRⅠ共检测到51个变异位点,位点变异率为8.76%;线粒体Cyt b部分序列发现31个变异位点,位点变异率为5.33%,未见插入及缺失现象,变异类型全部为碱基置换。共定义了16个线粒体HVRⅠ单倍型,其中吉林与内蒙种群存在共享单倍型,估计这两地间种群亲缘关系较近。4个地理种群中新疆种群拥有较高的遗传多样性(0.94)。中国狼种群总体平均核苷酸多态性为2.27%,与世界其他国家地区相比,中国狼种群拥有相对较高的遗传多样性。通过线粒体HVRⅠ单倍型构建的系统进化树可以看出,中国狼在进化上分为2大支,其中位于青藏高原的青海种群独立为一支,推测其可能长期作为独立种群进化。基于青海种群与新疆,内蒙种群的线粒体Cyt b遗传距离,推测中国狼2个世系可能在更新世冰川时期青藏高原受地质作用急速隆起后出现分歧,分歧时间大约在1.1 MY前。     

黑线姬鼠两亚种(中国东北地区及俄罗斯远东地区的东北亚种和朝鲜半岛的朝鲜亚种) 的线粒体DNA 序列缺少趋异性

为了检测黑线姬鼠两亚种(来自中国东北地区、俄罗斯远东地区的东北亚种和朝鲜半岛的朝鲜亚种)线
粒体DNA 的变异水平并确定朝鲜亚种的分类地位,我们测序分析了两亚种的线粒体DNA 细胞色素b 的部分序列
(1 054 bp)和控制区的部分序列(860 bp),并与基因库中黑线姬鼠相应的单倍型序列进行了比较。可以看出东
北亚种的序列显示出某些分异,可以被分为2 或3 个亚群,所以我们提出需要更多标本的DNA 分析来确定东北
亚种的分类地位。另外,来自韩国的朝鲜亚种的序列,与来自中国东北地区龙江和哈尔滨的东北亚种的两个亚
群相似(1 个亚群是细胞色素b 的两个单倍型,另1 个是控制区的两个单倍型),表明基于线粒体DNA 序列的遗
传多样性与现今基于形态特征对这些姬鼠的分类所得结果是不一致的。因此我们认为来自韩国的朝鲜亚种是一
个只在形态特异上不同于东北亚种的地方亚种,我们建议通过其他DNA 标记来进一步验证其亚种地位。我们还
认为朝鲜半岛不是最近的冰川期黑线姬鼠残遗种的保护区。     

Phylogeography and conservation genetics of Eld's deer (Cervus eldi)

Eld's deer (Cervus eldi) is a highly endangered cervid, distributed historically throughout much of South Asia and Indochina. We analysed variation in the mitochondrial DNA (mtDNA) control region for representatives of all three Eld's deer subspecies to gain a better understanding of the genetic population structure and evolutionary history of this species. A phylogeny of mtDNA haplotypes indicates that the critically endangered and ecologically divergent C. eldi eldi is related more closely to C. e. thamin than to C. e. siamensis, a result that is consistent with biogeographic considerations. The results also suggest a strong degree of phylogeographic structure both between subspecies and among populations within subspecies, suggesting that dispersal of individuals between populations has been very limited historically. Haplotype diversity was relatively high for two of the three subspecies (thamin and siamensis), indicating that recent population declines have not yet substantially eroded genetic diversity. In contrast, we found no haplotype variation within C. eldi eldi or the Hainan Island population of C. eldi siamensis, two populations which are known to have suffered severe population bottlenecks. We also compared levels of haplotype and nucleotide diversity in an unmanaged captive population, a managed captive population and a relatively healthy wild population. Diversity indices were higher in the latter two, suggesting the efficacy of well-designed breeding programmes for maintaining genetic diversity in captivity. Based on significant genetic differentiation among Eld's deer subspecies, we recommend the continued management of this species in three distinct evolutionarily significant units (ESUs). Where possible, it may be advisable to translocate individuals between isolated populations within a subspecies to maintain levels of genetic variation in remaining Eld's deer populations.     

Phylogeny and genetic structure of the goitered gazelle (Artiodactyla,Bovidae) in north-western China indicated by the hypervariable mitochondrial control region

The goitered gazelle, Gazella subgutturosa, is a medium-sized ungulate inhabiting arid and semi-arid regions in the Middle East and central Asia. The intraspecific classification of the species remains unclear. We analysed the genetic diversity in mitochondrial DNA control region (CR) sequences (976?bp) from 104 wild samples from the Xinjiang Uyghur Autonomous Region (XUAR) in north-west China, and reconstructed phylogeny with additional sequences from across the species’ range. We detected 58 haplotypes in XUAR populations, all but three of which were specific to single sampling sites. The phylogenetic analysis displayed two obvious clades of mtDNA haplotypes and the other haplotypes differed from the two clades. A median-joining network showed three groups of haplotypes were to a high extent concordant with the phylogenetic tree. The haplotype clustering was consistent with their geographic distribution. Nei’s net sequence divergences amongst the three groups ranged from 0.010 to 0.018 and indicated three subspecies, two of which inhabit XUAR. We detected strong differentiation between northern (NX) and southern (SX) XUAR populations overall (F_ST?=?0.4448, P?相似文献   

Phylogeographic differentiation in the mitochondrial control region in the koala, Phascolarctos cinereus (Goldfuss 1817)

The koala, Phascolarctos cinereus, is a geographically widespread species endemic to Australia, with three currently recognized subspecies: P.c. adustus, P.c. cinereus, and P.c. victor. Intraspecific variation in the mitochondrial DNA (mtDNA) control region was examined in over 200 animals from 16 representative populations throughout the species’ range. Eighteen different haplotypes were defined in the ≈ 860 bp mtDNA control region, as determined by heteroduplex analysis/temperature gradient gel electrophoresis (HDA/TGGE). Any single population typically possessed only one or two haplotypes yielding an average within-population haplotypic diversity of 0.180 ± 0.003, and nucleotide diversity of 0.16%. Overall, mtDNA control region sequence diversity between populations averaged 0.67%, and ranged from 0% to 1.56%. Nucleotide divergence between populations averaged 0.51%, and ranged from 0% to 1.53%. Neighbour-joining methods revealed limited phylogenetic distinction between geographically distant populations of koalas, and tentative support for a single evolutionarily significant unit (ESU). This is consistent with previous suggestions that the morphological differences formalized by subspecific taxonomy may be interpreted as clinal variation. Significant differentiation in mtDNA-haplotype frequencies between localities suggested that little gene flow currently exists among populations. When combined with microsatellite analysis, which has revealed substantial differentiation among koala populations, we conclude that the appropriate short-term management unit (MU) for koalas is the local population.