小熊猫种群遗传结构和地理分化

本文采用分子系统地理学的研究方法 ,对我国小熊猫 (Ailurusfulgens)地理分布格局的形成原因进行了探讨。我们从四个地理单元的 32号样品中成功地扩增出了 371bp的线粒体DNA控制区片段 ,在所有可比较的 35 7bp的序列中 ,发现 2 9个变异位点 ,其中转换和颠换分别为 2 1和 8,没有插入 /缺失。在四个地理单元中 ,共有 16种线粒体DNA单倍型 ,且在各地理单元中都具有较高的单倍型的多态性。进一步分析表明 ,各单倍型之间的遗传距离平均为 1 6 0 % ,76 5 9%的遗传差异发生在地理单元间 ,仅 2 3 4 1%发生在单元内。分子变异分析和系统重建结果也表明 ,各地理单元之间不存在共享的单倍型 ,YN (云南地理单元 )与XL (相岭地理单元 )和QL (邛崃地理单元 )之间存在着显著的遗传分化 ,FST分别为 0 336和 0 35 1(P <0 0 0 1) ,其余地理种群之间分化不明显 (P >0 0 5 ) ,单倍型缺乏比较明显的地理分布格局 ,各地理单元中的单倍型相互散布在不同的分布群中。经Fs检验 (Fs=- 10 12 1) ,并结合化石资料 ,我们认为由于受第四纪气候和环境变化的影响 ,小熊猫种群在进化过程中曾经历种群暴发而不断扩散 ,从而形成今天的分布格局。     

东北地区棕背鼠平种群遗传结构及亚种分类

Using partial sequences of mtDNA control region,we sought genetic diversity,population genetic structure and subspecies classification in 5 populations of Myodes rufocanus from Northeast China and Hokkaido,Japan. After sequencing a 616 bp segment of control region,we detected 45 haplotypes based on 57 variable sites among 55 individuals. Our results revealed that high-level haplotype diversity and slightly less nucleotide diversity occurred in these populations. AMOVA analysis showed that high-level genetic differentiation happened between populations due to 64.70% genetic diversity and Fst ranging from 0. 240 to 0. 814. In a phylogenetic analysis,the haplotypes from Northeast China split into two groups:Daxing’anling-Xiaoxing’anling-Wandashan and Hailin-Dahailin. This suggested that we can separate the populations from Northeast China into two subspecies,M . r. irkutensis and M. r. Changbaishanensis respectively corresponding with the former and latter areas.     

塔里木兔种群遗传结构的初步探讨

塔里木兔作为中国特有种, 其种群遗传结构直到现在还未知。我们从采自于新疆维吾尔自治区3 个种群的25 号样品中扩增得到529 bp 线粒体DNA 控制区片段, 共发现存在76 个多态性位点。全部样品中定义了19 个单倍型, 每个种群都显示了很高的单倍型多态性。进一步分析表明, 3 个种群存在明显的遗传分化和较低的基因流。通过错配分布和Fu’s 中性检验分析发现, 阿克苏(AKS) , 若羌(RQ) 和疏勒(SL) 种群相对比较稳定。     

白鱼线粒体DNA控制区结构和种群遗传多样性分析

用特异性引物对白鱼（Anabarilius grahami）DNA进行PCR扩增,获得了白鱼线粒体DNA控制区基因全序列（930 bp）。控制区T、C、A和G碱基组成为29.8%、22.5%、33.0%和14.7%。对照其他已报道的鱼类控制区结构,对白鱼控制区结构进行了分析,识别了其终止序列区、中央保守区和保守序列区,找到了终止相关的序列TAS以及保守序列（CSB-F、CSB-D、CSB-1、CSB-2、CSB-3）。同时运用DNA分析软件对白鱼一个驯养种群（中国科学院昆明动物研究所珍稀鱼类繁育中心）及两个自然地理种群（江川县明星鱼洞、江川县牛摩村）进行了遗传多样性分析。结果显示：两个自然种群存在较强基因交流,未出现遗传分化;人工驯养种群遗传多样性最高,种群复壮程度较好。     

白鱼线粒体DNA控制区结构和种群遗传多样性分析

用特异性引物对白鱼(Anabarilius grahami)DNA进行PCR扩增,获得了白鱼线粒体DNA控制区基因全序列(930bp)。控制区T、C、A和G碱基组成为29.8%、22.5%、33.0%和14.7%。对照其他已报道的鱼类控制区结构,对白鱼控制区结构进行了分析,识别了其终止序列区、中央保守区和保守序列区,找到了终止相关的序列TAS以及保守序列(CSB-F、CSB-D、CSB-1、CSB-2、CSB-3)。同时运用DNA分析软件对白鱼一个驯养种群(中国科学院昆明动物研究所珍稀鱼类繁育中心)及两个自然地理种群(江川县明星鱼洞、江川县牛摩村)进行了遗传多样性分析。结果显示:两个自然种群存在较强基因交流,未出现遗传分化;人工驯养种群遗传多样性最高,种群复壮程度较好。     

中国主要家鹅品种的遗传分化研究

利用PCR和DNA测序技术扩增了15个中国家鹅品种线粒体DNA控制区部分序列（1042bp）。研究结果表明：伊犁鹅与14个品种间的核苷酸分歧度最高,为3．805％～4．067％;不同品种内核苷酸多样度表现出较大的差异,为0～0．116％。除伊犁鹅外的14个家鹅品种中,豁眼鹅与其他品种间的核苷酸分歧度为0．211％～0．272％,明显高于其他品种间的0～0．094％。中国家鹅品种的遗传分化格局与地理分布有关,豁眼鹅的分歧时间较早,遗传漂变是导致豁眼鹅遗传分化的主要因素（Nm=0．02～0．54）,基因流则是另外13个家鹅品种间遗传分化不明显的主要因素（Nm=12．0～65．33）．     

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。     

马鹿阿拉善亚种遗传多样性和群体结构

马鹿阿拉善亚种（Cervus elaphus alashanicus）又称阿拉善马鹿,目前仅分布于贺兰山地区,是我国马鹿亚种分布范围最狭窄的一个隔离种群。为了解阿拉善马鹿的种群遗传多样性及遗传变异情况,以对该种群的保护提供科学参考,对在贺兰山采集的93个野生个体新鲜粪便样本的线粒体控制区部分序列（991 bp）进行扩增和分析,共检测到68个变异位点,定义16种单倍型,平均单倍型多样性为0.405,平均核苷酸多样性为0.00232,说明种群遗传多样性水平较低。中性检验和错配分布分析表明阿拉善马鹿曾出现过种群扩张,贝叶斯天际线分析（BSP）显示扩张时间约在末次冰盛期（0.028—0.010 Ma）。FST检验表明阿拉善马鹿种群内存在显著遗传分化,系统发育树和单倍型网络图分析表明群体间没有明显的系统地理格局。本研究表明阿拉善马鹿目前种群遗传多样性较低,建议加大对该亚种的关注和保护力度。       

高原鼠兔四个地理种群的遗传多样性与遗传分化

采用7 个多态微卫星DNA 标记分析了4 个高原鼠兔地理种群(海晏种群、西大滩东种群、西大滩西种群和昆仑山种群)的遗传多样性和遗传分化。采用多态信息含量(PIC)、期望杂合度(H_e )、观测杂合度(H_o)、基因流(N_m )和基因分化系数(F_st )对种群及物种的遗传多样性水平进行分析;计算各种群间的遗传距离(GD)、遗传相似度(GI)以及遗传距离与地理距离的相关系数,并进行UPGMA 聚类分析。研究结果显示,高原鼠兔的遗传多样性在小哺乳动物中处于较高水平, 其H_e 和H_o 的平均值分别为0. 5332 和0. 6003, 其F_st 为0. 0975,即有9. 75% 的变异存在于种群之间,即变异主要存在于种群内部。4 个种群间的杂合度与多态信息含量均无显著差异,说明它们的遗传多样性水平基本相当。海晏种群与其余3 个种群的遗传分化均达到了中度分化水平(F_st = 0.1043),而另3 个种群间几乎没有分化(F_st = 0. 0253)。Mantel test 结果表明地理距离与遗传距离间没有显著的相关性。     

环境因子对雉鸡甘肃亚种种群遗传多样性的影响(英文)

采用聚合酶链式反应(PCR)和直接测序的方法,测定了雉鸡甘肃亚种9个种群118个样本的线粒体DNA(mtDNA)控制区(D-loop)1150个碱基长度的基因序列,43个变异位点产生51个单倍型。环境因子与种群遗传变异的相关性研究表明,序列变异与经度(r=0.725,P<0.05)、年平均温度(r=0.833,P<0.05)呈显著正相关,核苷酸多样性与经度(r=0.686,P<0.05)、年平均温度(r=0.844,P<0.05)呈显著正相关。片段化与低温是导致雉鸡甘肃亚种遗传多样性的主要因素。序列变异及核苷酸多样性与温度的变异系数呈显著负相关(r序列=-0.679,P<0.05;r核苷酸=-0.669,P<0.05)。温度越稳定地区雉鸡甘肃亚种的遗传多样性越高。     

Bidirectional introgressive hybridization between Lepus capensis and Lepus yarkandensis

Lepus capensis and Lepus yarkandensis are two well-established hare species with different habitat preferences and obvious morphological distinctions. L. capensis is common and widespread while L. yarkandensis is an endemic species with a restricted distribution in the Tarim Basin of western China. During field sampling, individuals with a distinct phenotype were found in the contact zone between the two species. To understand the origin of these unclassified individuals, we analyzed morphological and genetic data from 700 individuals including L. yarkandensis, L. capensis and the unclassified individuals. Morphological analyses of the unclassified individuals revealed that they lie between L. yarkandensis and L. capensis. Genetic analyses based on species-specific molecular markers (mitochondrial control region and SRY) showed that the unclassified populations have mtDNA and SRY genes from both L. capensis and L. yarkandensis, suggesting that the unclassified populations result from hybridization between the two species. Interestingly, many identical and/or very similar mtDNA haplotypes were shared between L. capensis populations and L. yarkandensis populations close to their contact zones, which further suggests the existence of extensive bidirectional mtDNA introgression. Similarly, we found evidence for SRY introgression, though it existed at a lower level compared to mtDNA introgression.     

基于微卫星标记的中国大陆地区野猪种群结构分析与亚种分化

对中国大陆地区分布的野猪亚种分类尚存在争议.本研究通过对野猪11个微卫星位点的变异分析,探讨了中国大陆地区野猪的遗传结构,以期对野猪亚种分类问题有所启迪.对野猪华北、华南和东北种群的分析表明,各种群基因库中都维持了较高的遗传变异水平.基于遗传距离构建的系统树分析发现,研究中所涉及的所有亚种在系统树中混杂,没有任何亚种在其中构成显著的支系.基于微卫星变异的FCA分析不能区分华南、华北、东北三个种群.基于Fst检验的遗传差异分析发现,长江两侧的华南、华北种群之间的遗传差异较小(Fst=0.014),表明长江两侧的野猪可能存在着较高水平的基因流,长江并非是一个有效的空间隔离;东北地区野猪和华北、华南地区野猪之间的遗传差异相对较大(Fst=0.040、0.042),东北野猪可以作为独立的亚种S.s.ussuricus.     

Genetic diversity of the toll-like receptor 2 (TLR2) in hare (Lepus capensis) populations from Tunisia

Toll-like receptors (TLRs) are a major group of proteins that recognize molecular components of infectious agents, known as pathogen associated molecular patterns (PAMPs). The structure of these genes is similar and characterized by the presence of an ectodomain, a signal transmembrane segment and a highly conserved cytoplasmic domain. The latter domain is homologous to the human interleukin-1 receptor (IL1R) and human IL-18 receptor (IL-18R) and designated TIR domain. The latter domain of the TLR genes was suggested to be very conservative and its evolution is driven by purifying selection. Variability and evolution of the TIR sequences of TLR2 gene were studied in three hare populations from Tunisia with different ecological characteristics (NT–North Tunisia with Mediterranean, CT–Central Tunisia with semi-arid, and ST–South Tunisia with arid climate). Sequencing of a 372 bp fragment of TIR2 revealed 25 alleles among 110 hares. Twenty variable nucleotide positions were detected, of which 7 were non-synonymous. The highest variability was observed in CT, with 16 polymorphic positions. In ST, only 4 polymorphic nucleotide positions were detected with all diversity values lower than those recorded for the other two populations. By using several approaches, no positive selection was detected. However, evidence of purifying selection was found at two positions. The logistic models of the most common TIR2 protein variant that we run to examine whether its occurrence was affected by climatic variation independent of the geographic sample location suggested only a longitudinal effect. Finally, the mapping of the non-synonymous mutations to the inferred tertiary protein structure showed that they were all localized in the different loop regions. Among all non-synonymous substitutions, three were suggested to be deleterious as evidenced by PROVEAN analysis. The observed patterns of variability characterized by low genetic diversity in ST might suggest that the TIR region was more affected, than other markers, by genetic drift or/and that these patterns were shaped by different selective pressures under different ecological conditions. Notably, this low diversity was not detected by other (putatively neutral) microsatellite markers analysed in the course of other studies. But low diversity was also found for two MHC class II adaptive immune genes. As expected from functionally important regions, the evolution of the TIR2 domain is mainly driven by purifying selection. However, the occurrence of deleterious non-synonymous substitutions might highlight the flexible evolution of the TIR genes and/or their interactions with other proteins.     

Genetic divergence of Troglodytes troglodytes islandicus from other subspecies of Eurasian wren in northwestern Europe

The Icelandic subspecies of Eurasian wren Troglodytes troglodytes islandicus has been described as a large wren which is sedentary on the island. It is one member of a large passerine complex which is widely distributed over the Holarctic except the Arctic. The taxonomic affiliation of the subspecies is mainly based on variation in plumage and on the song complexity. This study investigated the genetic differentiation of T. t. islandicus among the Eurasian wren subspecies in northwestern Europe, and especially in relation to its geographically proximate populations in the Faroe Islands, Scotland, southern Norway, Sweden and Denmark. Troglodytes t. islandicus and the Faroese subspecies (T. t. borealis) were genetically differentiated from the other subspecies (T. t. indigenus and T. t. troglodytes) with an estimated time of divergence from this group during the last glacial maximum; 21 thousand years before present (KYBP) [44–8]. A clear but a more recent split was observed between T. t. islandicus and T. t. borealis 12 KYBP [28–4].     

The changing status of the Brown hare (Lepus capensis L.) in Britain

Game bag records are used to examine temporal and geographical changes in numbers of Brown hares. Records are taken from a survey made by the Oxford Bureau of Animal Population in 1938, which covered over 400 estates, and from the Game Conservancy's National Game Census, which has been monitoring shooting records of between 400 and 500 estates since 1961. Eastern regions of Britain had higher bags of hares than western regions in the three periods; 1891–1910, 1917–1936, 1961–1978. Hare game bags were generally high in counties with large proportions of tilled land. There was no consistent temporal trend in bags from different areas before 1938, but all areas show a considerable reduction in bags since 1961. This reduction is statistically significant. Time-series analysis of one extended set of data did not show evidence of cyclic fluctuations.     

Genetic structure and divergence of tench Tinca tinca European populations

The tench Tinca tinca is a freshwater species with human-mediated translocations, aquaculture interest and limited information on its genetic structure. mtDNA sequencing analysis of control region and two genes in 50 individuals from five European populations identified two phylogroups, with greater variability than that reported until now, and a hybridization zone in the Danube River region. Restriction analyses of additional samples reveal the complicated genetic structure characteristics of tench's wild and translocated populations, supporting future breeding practices.     

Isolation and characterization of uteroglobin from the lung of the hare (Lepus capensis)

Uteroglobin has been purified from hare lung by gel filtration and chromatography on carboxymethyl-cellulose. Hare uteroglobin appears homogeneous by electrophoresis under both denaturing and nondenaturing conditions. Its chemical and immunological properties as well as its ability to bind progesterone are compared to those of rabbit uteroglobin. The two proteins have the same N-terminal residue (glycine) and both lack tryptophan but differ in amino acid composition. Sodium dodecyl sulfate-gel electrophoresis shows that hare uteroglobin is composed of two subunits of identical Mr (about 7000) held together by disulfide bridges. The amino acid composition indicates a subunit composed of 65-67 residues, which is compatible with the apparent Mr observed. Thus, hare uteroglobin appears to be slightly smaller than the rabbit protein. Hare uteroglobin partially reacts with anti-rabbit uteroglobin in a radioimmunoassay and also binds progesterone, although this binding is relatively unaffected by dithiothreitol. The synthesis of hare uteroglobin in the uterus appears to be rather insensitive to ovarian steroid hormones.