千岛湖岛屿社鼠的扩散特征

2009年7月—11月,2010年3月—11月对千岛湖两个岛屿上的社鼠(Niviventer confucianus)种群进行标志重捕,通过分析扩散个体的性别、年龄及扩散距离等,探讨陆桥岛屿环境下社鼠的扩散特征。研究结果显示:岛屿环境下社鼠的扩散率为37.96%,不同季节社鼠的扩散率存在差异,社鼠倾向于在春季发生扩散,尤其是3月份,社鼠扩散个体数最多;对于整个捕获史而言,雌雄扩散个体数存在极显著的差异(x~2=12.542,df=1,P0.001),雄性个体更倾向于发生扩散;而在繁殖高峰期,当怀孕鼠存在时,雄性扩散数亦大于雌性,两者存在显著差异(x~2=4.504,df=1,P=0.034)。扩散个体体重的季节差异不显著;扩散与社鼠的年龄密切相关,社鼠更加倾向于在亚成年阶段发生扩散;另外,家群大小对社鼠扩散个体数量也有显著影响,家群越大,扩散个体越多;对扩散距离进行分析发现存在显著的性别差异(t=-9.229,df=50,P0.001),雌性个体的平均扩散距离为(282.97±16.14)m,显著大于雄性的(146.70±6.80)m,而扩散距离与年龄、体重、最大活动距离均无显著相关性。     

神农架川金丝猴人工补食群的遗传多样性和亲缘关系

以湖北神农架国家级自然保护区的川金丝猴人工补食群体为研究对象,利用微卫星遗传标记对该群体的遗传多样性和亲缘关系进行研究,并对其种群的遗传多样性发展趋势进行了预测。结果显示,12个微卫星位点在该补食群体中共检测到50个等位基因,平均观察杂合度和平均期望杂合度分别为0.668和0.630,多态信息含量为0.442-0.696,平均0.567。亲权鉴定中共鉴定出11个父-母-子单元,各单元未有近亲繁殖的状况。亲缘系数结果显示具有亲缘关系的个体对达21.64%,群体平均亲缘系数为0.1108,现6个家庭单元中有两对候选亲本具有亲缘关系,表明该群体存在较高的近交风险。遗传多样性变化趋势的模拟结果表明,种群的数量对遗传多样性的影响比较大,群体中雄雌比例也对遗传多样性的损失有影响;为避免近亲交配,保持群体的遗传多样性水平,建议进一步做好人工补食群金丝猴的个体识别,完善家庭系谱,明确繁殖个体的遗传背景;引入一批有效的建群者来增加种群的数量及优化雄雌的比例。     

千岛湖岛屿社鼠的种群年龄结构和性比

2009年7月至11月以及2010年3月至11月在千岛湖地区2个岛屿上对社鼠(Niviventer confucianus)种群进行标志重捕,通过对社鼠种群年龄结构和性比的研究,探讨陆桥岛屿环境下生境片段化对社鼠种群结构的影响。结果显示:社鼠种群年龄结构整体上均表现为由上半年幼年组和亚成年组占优势逐渐过渡到下半年成年组和老年组占绝对优势,岛屿环境对社鼠年龄结构变化的影响与陆地环境有所不同;两岛社鼠种群数量与性比(♀:♂)之间均存在显著的负相关性(B岛2010年7-11月除外),当种群数量处于高峰期时,雌性少于雄性,而种群数量处于低潮期时,雌性多于雄性,这可能是社鼠种群数量变动内部调节机制的一种表现;由于9-10月和2-3月的繁殖高峰以及高的胎仔数,翌年上半年种群数量就能恢复并达到全年最高峰。     

年龄、性别及季节因素对千岛湖岛屿社鼠最大活动距离的影响

2009年7-11月及2010年3-11月,在千岛湖2个岛屿上进行社鼠(Niviventer confucianus)的标志重捕,根据春、夏、秋3个季节将重捕4次以上的社鼠进行最大活动距离计算,分析年龄、性别及季节对岛屿社鼠最大活动距离的影响.结果显示,岛屿间无显著差异;将2岛数据合并后,幼年、亚成年、成年及老年4个年龄组社鼠最大活动距离之间差异极显著;雄性社鼠最大活动距离极显著地大于雌性,4个年龄组雌雄之间的最大活动距离均表现为雄性＞雌性,但仅成年组雌雄之间存在极显著差异;春、夏、秋3个季节之间的最大活动距离差异极显著,而仅亚成年组在3个季节之间存在极显著差异,雌性和雄性社鼠均表现春季＜夏季＜秋季,但只在春季表现出雌雄个体之间差异极显著,与以往巢区研究结果不一致,可能反映了岛屿环境下社鼠巢区活动的特殊性.显示岛屿隔离环境对小型哺乳动物巢区活动有影响,但这种岛屿效应仍有待深入研究.     

基于粪便DNA的贺兰山岩羊亲权鉴定和婚配制研究

2017年7-8月和11-12月在贺兰山岩画风景区采集到369份岩羊新鲜粪便样本,用多态性较高的10个微卫星位点进行基因分型,共识别出282只岩羊个体。通过复合扩増和牙釉蛋白基因PCR法共鉴定出152只雄性,130只雌性。微卫星分析得到平均等位基因（Na）为10.1,平均观测杂合度（Ho）为0.7737,平均期望杂合度（He）为0.6512,平均多态信息（PIC）为0.6129。运用Cervus3.0软件进行亲权鉴定,并用Kingroup V2计算个体间的亲缘系数（r）,作为亲权鉴定的补充,共鉴定出父-母-子7对,父-子21对,母-子19对。根据亲缘关系对岩羊的婚配制进行推测分析,表明岩羊婚配制应属一雄多雌。     

千岛湖社鼠种群遗传现状及与生境面积的关系

以千岛湖地区13个岛屿上的社鼠(Niviventer confucianus)种群为研究对象,利用13个微卫星位点分析了13个社鼠种群的遗传现状,并探讨了种群遗传现状与岛屿面积大小之间的关系。研究结果显示,13个社鼠种群的平均观测等位基因数(Na)与平均有效等位基因数(Ne)分别为7.385,5.952,平均期望杂合度(He)与平均观测杂合度(Ho)分别为0.819,0.930,平均多态信息含量(PIC)为0.760,说明13个社鼠种群均具有较高的遗传多样性。13个种群间的分化系数(Fst)为0.053,表明种群间的遗传分化较小。3个面积较大且相近岛屿上社鼠种群,即高仙阁种群 (Gaoxiange Island,G);乌石T岛种群 (Wushi T Island,WT);东门岛种群 (Dongmen Island,DM)间的Fst值均小于0.05,表明种群间无分化,而小岛种群与大岛种群间的分化却比较明显。此外,一元回归结果显示,多态信息含量(PIC)和Shannon多样性指数(I)与岛屿面积大小之间均存在显著地正相关关系。以上结果说明,在社鼠种群进化过程中,生境面积的缩小可能使种群的遗传结构发生改变,并有可能导致种群的快速进化。     

天鹅洲迁地保护江豚种群近亲繁殖状况评估

长江江豚(Neophocaena asiaeorientalis asiaeorientalis)已处于极度濒危状况,迁地保护被认为是避免其灭绝最有希望的保护措施。本文选用21个多态性微卫星标记对2010年10月天鹅洲迁地保护江豚种群进行了亲子鉴定和亲缘关系分析,以检测该种群的近亲繁殖状况,为种群管理提供参考信息。本研究从18个体中检测到3个父-母-子家庭,以及母子和父子各1对。由于检测到的亲子关系较少,单从亲子鉴定结果不能判断该种群是否存在近亲繁殖。然而,亲缘关系分析结果表明,该迁地保护江豚种群的平均亲缘系数r为0.118 2,候选亲本间亲缘系数r为0.115 2,均显著高于长江江豚自然种群。而且,天鹅洲迁地保护江豚种群中具有亲缘关系的个体对达26.14%,高于自然种群6倍以上。此外,该种群的近交系数(Fis)为0.046。基于亲缘系数和近交系数的分析结果均表明,该种群存在较高的近交风险或者可能已经发生近交。本研究建议将种群中亲缘关系最多的雌性F34和雄性M45移出,并以每代(约5年)按雌雄1∶1的比例引进2头可繁殖个体,以降低近亲繁殖风险。此外,建议尽快为该迁地保护江豚种群构建遗传谱系,以便今后开展种群遗传管理。     

广聚萤叶甲地理种群间交配选择及子代的发育表现

为探究分布于我国不同地域的广聚萤叶甲(Ophraella communa)种群之间的分化现状,本文对来自南京、长沙和福州等3个地理种群的交配选择行为及杂交后代发育表现进行了研究.结果表明,在试验观察的6 h内南京种群与福州种群间个体发生交配的概率显著低于对照(种群内雌雄个体间的交配),但南京种群与长沙种群个体间发生交配的概率与对照无显著差异;南京和福州种群的雄性与同种群雌性交配选择次数显著多于与异种群雌性交配的次数,但南京与长沙种群间个体交配的次数与对照无显著差异.3个地理种群间个体杂交后代在卵孵化率、幼虫化蛹率和成虫羽化率等发育特性上与对照(种群内个体自交)无显著差异.根据研究结果推测,广聚萤叶甲南京种群与福州种群间在个体交配行为上存在着一定程度的交配前隔离.     

雄性普通黄颡鱼与所保护受精卵间的亲缘关系分析

父母通过保护自己的子代来确保其繁殖的成功率.在普通黄颡鱼(Pelteobagrus fulvidraco)中,雄性普通黄颡鱼具有筑巢产卵保护后代的习性,其所保护的子代与其是否有亲缘关系是有待探讨的问题.本文利用10对微卫星分子标记鉴定12窝普通黄颡鱼受精卵与护卵鱼之间的亲缘关系,并对子代的遗传多样性进行分析.在单亲鉴定中,累积非父排除概率为0.9986,平均父权相对机会(RCP)在99.989%-99.999%之间,每个子代在10个微卫星位点上的累积PI值在2006.73-604464.07之间.同时在亲权鉴定分析中,发现3窝卵子的等位基因来自2个母亲,说明雄性黄颡鱼可以和2条雌性黄颡鱼发生交配;在遗传多样性分析中,黄颡鱼子代的平均等位基因数为11.7, 无偏观测杂合度值(Ho)在0.2473-0.9866之间,多态信息含量(PIC)值0.7096-0.8993之间.通过亲权鉴定分析,可以确认看护受精卵的雄性普通黄颡鱼与受精卵间的亲子关系.     

黑头酸臭蚁微卫星标记的分离与开发(英文)

【目的】本研究旨在分离黑头酸臭蚁Tapinoma melanocephalum基因组微卫星标记,确定这些微卫星位点的多态性。【方法】使用454 GS-FLX焦磷酸测序技术开发来自中国华南陆地和岛屿的11个黑头酸臭蚁地理种群基因组微卫星位点。从随机设计的100对微卫星引物中筛选出10对引物,用于确定黑头酸臭蚁4个地理种群［东澳岛(DAD)、荷包岛(HBD)、梅州(MZ)和山咀(SJ)］10个微卫星位点的多态性,分析种群遗传多样性和种群分化。【结果】从11个黑头酸臭蚁地理种群基因组中成功开发和分离10对微卫星引物。在DAD, HBD, MZ和SJ 4个地理种群中,10个微卫星位点中7个有高多态性,这10个位点均显著偏离Hardy-Weinberg平衡;每个位点的等位基因数量(A)是3.50~9.00个,每个地理种群每个位点等位基因丰富度(A_R)在1.992~12.938之间。岛屿地理种群(DAD和HBD)的AR和预期杂合度(H_E)与大陆地理种群(MZ和SJ)的相比差异不显著。4个地理种群均显示高水平遗传分化(F_ST=0.15969);HBD和MZ种群与其他配对地理种群相比,遗传分化较高(F_ST=0.185),基因流较低,说明这两个种群基因流被限制。此外,遗传变异来自种群内个体之间。【结论】筛选新的微卫星位点能够为研究黑头酸臭蚁种群结构和繁殖结构提供有效工具,以深入了解其传播机制。     

Sibship within samples of brown trout (<Emphasis Type="Italic">Salmo trutta</Emphasis>) and implications for supportive breeding

We analysed family relationships among brown trout from two small tributary populations that have been suggested as a source of individuals for supportive breeding, using variation at eight microsatellite loci. As a control, we analysed a sample of supposedly unrelated individuals representing a large anadromous population, and we simulated unrelated individuals based on the allelic distributions in all three samples. Two different approaches were used: (1) pairwise estimates of relatedness between individuals and (2) a method for partitioning individuals into half-sib and full-sib families. The anadromous population did not show evidence of a significant number of closely related individuals. In both tributary populations, however, the distributions of pairwise relatedness estimates suggested the presence of several related individuals, and sibship reconstruction suggested fewer families consisting of more individuals than were observed for the simulated individuals. The expected increase of inbreeding coefficient in the two samples due to family structure was 0.026 and 0.030 respectively. Moreover, tests for recent bottlenecks yielded significant outcomes in both populations suggesting a history of low effective population sizes. Depending on the effective population size of captive spawners and past effective population sizes in the populations it could be beneficial to conduct sib-avoidance matings, though this cannot eliminate inbreeding but only delay it. Alternatively, individuals from different populations could be crossed. Sibship reconstruction provided the clearest evidence for family structure, but pairwise relatedness is the best measure for designing mating schemes, as it allows for mating as unrelated individuals as possible rather than just avoiding mating between sibs.     

Mating system, philopatry and patterns of kinship in the cooperatively breeding subdesert mesite Monias benschi

In the first molecular study of a member of the threatened avian family, Mesitornithidae, we used nine polymorphic microsatellite loci to elucidate parentage, patterns of within-group kinship and occurrence of extra-group paternity in the subdesert mesite Monias benschi, of southwest Madagascar. We found this cooperatively breeding species to have a very fluid mating system. There was evidence of genetic monogamy and polygynandry: of the nine groups with multiple offspring, six contained one breeding pair with unrelated helpers and three contained multiple male and female breeders with related helpers. Although patterns of within-group kinship varied, there was a strong positive relationship between group size and relatedness, suggesting that groups form by natal philopatry. There was also a strong positive correlation between within-sex and between-sex relatedness, indicating that unlike most cooperatively breeding birds, philopatry involved both sexes. In contrast to predictions of kin selection and reproductive skew models, all monogamous groups contained unrelated individuals, while two of the three polygynandrous groups were families. Moreover, although between-group variation in seasonal reproductive success was related to within-group female relatedness, relatedness among males and between the sexes had no bearing on a group's reproductive output. While kin selection may underlie helping behaviour in females, factors such as direct long-term fitness benefits of group living probably determine helping in males. Of the 14 offspring produced by fully sampled groups, at least two were sired by males from neighbouring groups: one by a breeding male and one by a nonbreeding male, suggesting that males may augment their reproductive success through extra-group paternity.     

Lizards in 'nuclear families': a novel reptilian social system in Egernia saxatilis (Scincidae)

Recent research has revealed unsuspected complexity in social organization among squamate reptiles. In particular, large Australian scincid lizards of the genus Egernia have been reported to occur in large aggregations of closely related individuals. However, the 'nuclear family' structure found in many other 'social' organisms (especially birds) has not been reported from reptiles. Our field studies on black rock skinks (Egernia saxatilis) in southeastern Australia document exactly this pattern. We quantified group composition using behavioural observations at regular intervals over three field seasons, and took tissue samples for parentage analysis. On the focal rock outcrop 72% of lizards were typically found as part of a stable social grouping, with individuals physically associated with other group members in a third of observations. Eighty-five per cent of juveniles lived in social groups, 65% in family groups with at least one of their parents (including 39% with both parents as revealed by parentage analysis of five microsatellite loci). Broader sampling in surrounding areas revealed similar patterns of group size, composition and relatedness. Overall, of the groups that contained more than one adult, 83% contained a single adult pair. Long-term monogamy and group stability were evident from our genetic data, with up to three annual cohorts of full-sib offspring living with their biological parents. Our data expand the range of social systems known for reptiles, and reveal strong convergence towards 'nuclear family' systems in distantly related vertebrates.     

Genetic consequences of group living in Mongolian gerbils

Social behavior can shape the local population genetic structure of mammals. Group living can increase pairwise genetic relatedness of mammals at a local level but differentiate the genetic structure at a population level through offspring philopatry and nonrandom mating. Our study aimed to test the hypothesis that social groups of Mongolian gerbils (Meriones unguiculatus) would consist of genetically related individuals due to offspring philopatry and would have distinct genetic structures because of restricted gene flow among social groups and nonrandom mating. We genotyped 327 wild gerbils, live captured from 28 social groups in Inner Mongolia, China, using nine microsatellite loci. The within-group pairwise genetic relatedness coefficient averaged 0.28 ± 0.14 (standard deviation), whereas the average pairwise genetic relatedness coefficient of the whole gerbil population was 0.0 ± 0.2. Additionally, the value of the global F statistic (F(st)) was 0.21, suggesting a substantial genetic differentiation among social groups of Mongolian gerbils. The Bayesian clustering divided the 327 gerbils into 23 distinct genetic clusters. Therefore, our results show that high within-group genetic relatedness and among-group genetic differentiation are the genetic consequences of group living in social mammals because of restricted gene flow, female philopatry, and nonrandom mating within social groups.     

Social and genetic structure of a supercolonial weaver ant, <Emphasis Type="Italic">Polyrhachis robsoni</Emphasis>, with dimorphic queens

We studied a population of the Australian weaver ant Polyrachis robsoni with regard to variation in the morphology of its winged queens using six newlydeveloped microsatellite markers. Morphometrically the queens fell clearly into two groups, macrogynes and microgynes, with the latter an isometric reduction of the former. Aggression tests showed that hostility between ants from different nests was minimal. Nests frequently contained numbers of both queen types, with microgynes about twice as numerous as macrogynes. Nestmate workers, microgynes, and macrogynes, were significantly related to others within their caste, with macrogynes more highly related than the other castes. Relatedness values between these groups of nestmates were also significant. Pairwise relatedness values were consistent with both queen morphs producing workers. At the population level, microgynes from different nests were also significantly related and there was a weak inverse relationship between pairwise relatedness value between individuals and distance between nests.We conclude that this species is supercolonial and that the two queen morphs are part of the same population. Received 19 July 2006; revised 16 October 2006; accepted 25 October 2006.     

Gene flow and population structure of the endemic Azorean bat (<Emphasis Type="Italic">Nyctalus azoreum</Emphasis>) based on microsatellites: implications for conservation

The Azorean bat (Nyctalus azoreum) is endemic to the Azores archipelago and is listed as endangered due to its reduced and fragmented distribution range. We assessed genetic diversity at eight microsatellite loci in 280 individuals from 14 locations throughout six islands. Overall, we found that the Azorean bat populations are not genetically impoverished. Indeed, the number of alleles per locus ranged from 8 to 10 and the observed heterozygosity ranged from 0.77 in Terceira to 0.83 in Faial. The highest genetic diversity and level of private alleles was observed in S. Miguel, the largest island, and the closest to the mainland. Private alleles occurred at all islands except in Graciosa. Global and pairwise F _ST among islands were all statistically significant, suggesting restricted gene flow. These results, together with those of factorial correspondence analysis, Bayesian clustering method, and individual assignment tests, corroborate the conclusions of a previous mtDNA based study, providing strong support for the existence of two major subpopulations: one includes all islands of the Central Group and the other corresponds to S. Miguel. Gene flow between them is very limited, suggesting that management plans should avoid translocations between these subpopulations. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Clustering of related individuals in a population of the Australian lizard, Egernia frerei

Stable social aggregations are rarely recorded in lizards, but have now been reported from several species in the Australian scincid genus Egernia. Most of those examples come from species using rock crevice refuges that are relatively easy to observe. But for many other Egernia species that occupy different habitats and are more secretive, it is hard to gather the observational data needed to deduce their social structure. Therefore, we used genotypes at six polymorphic microsatellite DNA loci of 229 individuals of Egernia frerei, trapped in 22 sampling sites over 3500 ha of eucalypt forest on Fraser Island, Australia. Each sampling site contained 15 trap locations in a 100 x 50 m grid. We estimated relatedness among pairs of individuals and found that relatedness was higher within than between sites. Relatedness of females within sites was higher than relatedness of males, and was higher than relatedness between males and females. Within sites we found that juvenile lizards were highly related to other juveniles and to adults trapped at the same location, or at adjacent locations, but relatedness decreased with increasing trap separation. We interpreted the results as suggesting high natal philopatry among juvenile lizards and adult females. This result is consistent with stable family group structure previously reported in rock dwelling Egernia species, and suggests that social behaviour in this genus is not habitat driven.     

Molecular genetic insights on cheetah (Acinonyx jubatus) ecology and conservation in Namibia

The extent and geographic patterns of molecular genetic diversity of the largest remaining free-ranging cheetah population were described in a survey of 313 individuals from throughout Namibia. Levels of relatedness, including paternity/maternity (parentage), were assessed across all individuals using 19 polymorphic microsatellite loci, and unrelated cheetahs (n = 89) from 7 regions were genotyped at 38 loci to document broad geographical patterns. There was limited differentiation among regions, evidence that this is a generally panmictic population. Measures of genetic variation were similar among all regions and were comparable with Eastern African cheetah populations. Parentage analyses confirmed several observations based on field studies, including 21 of 23 previously hypothesized family groups, 40 probable parent/offspring pairs, and 8 sibling groups. These results also verified the successful integration and reproduction of several cheetahs following natural dispersal or translocation. Animals within social groups (family groups, male coalitions, or sibling groups) were generally related. Within the main study area, radio-collared female cheetahs were more closely interrelated than similarly compared males, a pattern consistent with greater male dispersal. The long-term maintenance of current patterns of genetic variation in Namibia depends on retaining habitat characteristics that promote natural dispersal and gene flow of cheetahs.