高山嵩草种群在放牧干扰下遗传多样性的变化

利用SRAP (Sequence-related amplified polymorphism)分子标记, 对放牧干扰下的高山嵩草(Kobresia pygmaea)种群进行了遗传多样性研究, 获得了下述结果: 1) 20对SRAP引物组合共检测出448条清晰条带, 其中376条条带具有多态性, 多态位点百分率为83.93%, 随着放牧强度的增加, 高山嵩草种群多态位点百分数、Nei’s遗传多样性指数、Shannon信息指数均下降。2)高山嵩草种群具有较高的遗传多样性和较低的遗传分化(总的遗传多样性H_t为0.276 6, 种群内遗传多样性H_s为0.243 6, 遗传分化系数G_st为0.119 4, 基于G_st估计的基因流N_m^*为1.843 4), 但随着放牧强度的增加, G_st增加, N_m^*降低, 说明放牧限制了种群间的基因交流, 使种群发生遗传分化。3)不同放牧梯度的高山嵩草种群间的遗传距离很小, 但是随着放牧强度的增加, 种群间的遗传距离逐渐增加, 遗传一致度降低。根据遗传距离所构建的UPGMA聚类图中高山嵩草4个种群随着牧压的增加, 逐级聚在一起。     

大猿叶虫四地理种群的PCR-RFLP方法鉴别及遗传多样性分析

为了明确大猿叶虫Colaphellus bowringi Baly的遗传多样性水平及探索其种群快速鉴定的方法, 利用 7种限制性内切酶对其4个地理种群（江西龙南、江西修水、山东泰安、黑龙江哈尔滨）的线粒体COⅠ基因进行PCR-RFLP分析。结果表明: 利用AseⅠ, MboⅠ, NlaⅢ和RsaⅠ在大猿叶虫4个地理种群中均没检测到多态性; 利用AluⅠ和DraⅠ只检测到种群间的多态性; 利用HaeⅢ既检测到了种群间的多态性, 又在山东种群中检测到种群内多态性。根据酶切图谱, 共发现4种单倍型, 单倍型的特异性可以作为种群鉴别的标志。根据限制性片段共享度, 利用POPGEN 3.2计算4个种群的遗传距离, 并利用MEGA3.1进行聚类分析, 结果显示,大猿叶虫4个地理种群间的遗传距离大小与其相对地理距离的远近不相符, 其遗传变异程度与其滞育的特征也不相符。据此认为线粒体COⅠ基因的PCR-RFLP分析可以用于大猿叶虫不同地理种群的识别。     

A consensus linkage map of common carp (Cyprinus carpio L.) to compare the distribution and variation of QTLs associated with growth traits

The ability to detect and identify quantitative trait loci (QTLs) in a single population is often limited. Analyzing multiple populations in QTL analysis improves the power of detecting QTLs and provides a better understanding of their functional allelic variation and distribution. In this study, a consensus map of the common carp was constructed, based on four populations, to compare the distribution and variation of QTLs. The consensus map spans 2371.6 cM across the 42 linkage groups and comprises 257 microsatellites and 421 SNPs, with a mean marker interval of 3.7 cM/marker. Sixty-seven QTLs affecting four growth traits from the four populations were mapped to the consensus map. Only one QTL was common to three populations, and nine QTLs were detected in two populations. However, no QTL was common to all four populations. The results of the QTL comparison suggest that the QTLs are responsible for the phenotypic variability observed for these traits in a broad array of common carp germplasms. The study also reveals the different genetic performances between major and minor genes in different populations.     

贵州四个民族人群线粒体DNA编码区的多态性

目的研究贵州土家族、侗族、仡佬族和彝族人群线粒体DNA（mtDNA）编码区的核苷酸多态性。方法采用PCR-RFLP技术和DNA测序法对贵州4个群体145例样本mtDNA编码区的8个SNP基因座及COⅡ/tRNAlys基因间9 bp缺失进行多态性分析。结果贵州4个民族群体的9 bp缺失频率依次为土家族18.4%,侗族29.7%,仡佬族25%,彝族16.7%,平均缺失频率为22.8%;在8个SNP基因座中,A10398G、C10400T突变在4个群体中较普遍;A663G、C5178A和G12406A突变在部分民族群体中也有较高的频率;共检测出14种单倍型,其中仡佬族11种,土家族10种,侗族8种,彝族6种。结论贵州4个民族群体mtDNA编码区可能存在不同的突变热点,在等位基因和单倍型分布频率上存在一定差异。     

Preliminary data on the genetic differentiation of Mytilus desolationis Lamy 1936 and Aulacomya ater regia Powell 1957 (Bivalvia,mytilidae) in the Kerguelen Islands (Terres Australes et Antarctiques Françaises)

Summary Mussel populations in the Kerguelen Islands constitute an excellent model in which to study genetic differentiation, because of the exceptional geographic position of the islands with consequent very low external gene flow, the variety of biotopes that they occupy and their abundance there. Enzyme polymorphism and the electrophoretic variability of some loci have been studied in four populations of Mytilus desolationis Lamy 1936 and in four other populations of Aulacomya ater regia Powell 1957. In both species 67% of the loci were polymorphic. The electrophoretic variability of ACP-2, LAP-1, LAP-2, PGI and PGM in M. desolationis populations, and of ACP-2, LAP-1, LAP-2 and MDH in A. ater regia populations was analyzed by correspondence analysis. For M. desolationis the four populations studied were found to be heterogeneous; four loci contribute clearly to this differentiation. The populations from sheltered and exposed areas were distinguishable on the basis of the allelic frequencies of LAP-1 and LAP-2. The allelic frequencies of PGI and PGM allow further differentiation of the populations. For A. ater regia the four populations studied were distinguishable on the basis of the allele frequencies of ACP-2 and LAP-1 and the differences could not actually be related to their environmental conditions.     

Demographic Genetics of Brown Trout (Salmo Trutta) and Estimation of Effective Population Size from Temporal Change of Allele Frequencies

We studied temporal allele frequency shifts over 15 years and estimated the genetically effective size of four natural populations of brown trout (Salmo trutta L.) on the basis of the variation at 14 polymorphic allozyme loci. The allele frequency differences between consecutive cohorts were significant in all four populations. There were no indications of natural selection, and we conclude that random genetic drift is the most likely cause of temporal allele frequency shifts at the loci examined. Effective population sizes were estimated from observed allele frequency shifts among cohorts, taking into consideration the demographic characteristics of each population. The estimated effective sizes of the four populations range from 52 to 480 individuals, and we conclude that the effective size of natural brown trout populations may differ considerably among lakes that are similar in size and other apparent characteristics. In spite of their different effective sizes all four populations have similar levels of genetic variation (average heterozygosity) indicating that excessive loss of genetic variability has been retarded, most likely because of gene flow among neighboring populations.     

Genetic structure and differentiation of four lake populations of Coilia ectenes (Clupeiformes: Engraulidae) based on mtDNA control region sequences

To investigate genetic structure and differentiation of four lake populations of Coilia ectenes, a total of eighty-one individuals from four largest freshwater lakes (Dongting [DT], Poyang [PY], Chaohu [CH], Taihu [TH]) were analyzed based on mtDNA control region sequences. Seventy-five haplotypes were detected, and four to seven 38 bp tandem repeats were found. The indexes of nucleotide diversity (π) in these four populations were DT 0.78%, PY 1.09%, CH 0.81%, and TH 0.62%. Genetic distances within populations were between 0.63 and 1.14%, and from 0.76 to 1.60% among populations. A Neighbor–Joining (NJ) tree consisted of three major clades. Clade 1 consisted of 88.89, 26.09, and 4.55% individuals of DT, PY, and CH. Analysis of molecular variance (AMOVA) showed that most variances occurred within populations, suggesting that this is the main source of total variance. Our results suggest that the four lake populations of C. ectenes have not developed significant genetic structure.     

Diversity of killer cell immunoglobulin-like receptor genes in four ethnic groups in China

Killer cell immunoglobulin-like receptors (KIRs) show extensive variation in terms of gene content and allelic polymorphisms among different populations. The aim of this study was to analyze the distribution of KIR genes in the Bulang, Nu, Yugu, and Zhuang ethnic groups, which belong to four different language families in China, and thus to provide basic KIR gene and genotype data for these Chinese ethnic groups. Genotyping of 16 KIR genes was performed in 425 unrelated individuals using the polymerase chain reaction-sequence-specific oligonucleotide probe method with the Luminex MultiAnalyte Profiling System. The four framework KIR genes were detected in all four ethnic groups. The activating KIR genes as well as the inhibitory KIR genes showed extreme diversity among these four populations. A total of 35 distinct KIR genotypes were identified, one of which was previously unknown. The four most common genotypes were identified in all four populations and comprised 66.1~91.1% of all the genotypes. The group A haplotype occurred more frequently than the group B haplotype in the Nu, Yugu, and Zhuang populations, as in other East Asian populations. In contrast, the group A and group B haplotypes occurred equally in the Bulang population. The results of the present study suggested that the KIR genes and genotypes are diverse in these four ethnic groups, and each ethnic group has its own characteristic KIR distribution. The findings with respect to KIR gene diversity in these four populations should provide relevant genomic diversity data for the future study of viral infections, autoimmune diseases, and reproductive fitness.     

Construction of a high-density composite map and comparative mapping of segregation distortion regions in barley

Segregation distortion can negatively impact on gains expected using selection. In order to increase our understanding of genetic factors that may influence the extent and direction of segregation distortion, segregation distortion analyses were conducted in four different doubled haploid (DH) populations. A high-density composite map of barley was then constructed by integrating information from the four populations. The composite map contained 2,111 unique loci, comprising RFLP, SSR and DArT markers and spanned 1,136 cM. In the four populations investigated, the proportion of markers with segregation distortion ranged from 15 to 38%, depending on the population. The highest distortion was observed in populations derived by the microspore culture technique. Distorted loci tended to be clustered, which allowed definition of segregation distortion regions (SDRs). A total of 14 SDRs were identified in the 4 populations. Using the high-density composite map, several SDRs were shown to have consistent map locations in two or more populations; one SDR on chromosome 1H was present in all four populations. The analysis of haplotypes underlying seven SDRs indicated that in three cases the under-represented haplotypes were common across populations, but for four SDRs the under-represented haplotypes varied across populations. Six of the seven centromeric regions harboured SDRs suggesting that genetic processes related to position near a centromere caused the segregation distortion in these SDRs. Other SDRs were most likely due to the methods used to produce the DH populations. The association of the SDRs identified in this study and some of the genes involved in the process of haploid production described in other studies were compared. The composite map constructed in this study provides an additional resource for the barley community via increased genome coverage and the provision of additional marker options. It has also enabled further insights into mechanisms that underpin segregation distortion.     

Purification and biochemical characterization of glutathione S-transferases from four field populations of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

Glutathione S-transferases (GSTs) are a group of detoxification enzymes that catalyze the nucleophilic addition of glutathione to a wide variety of endogenous and xenobiotic compounds. In this study, GSTs were purified from four field populations of Bactrocera dorsalis with different insecticide susceptibilities by glutathione-agarose affinity chromatography. The populations were collected from Dongguan (DG) and Guangzhou (GZ) of the Guangdong Province, Haikou of the Hainan province (HN), and Kunming of the Yunnan province (YN), China. Differences in GST characteristics among the four populations were studied using purified enzyme samples through comparative SDS-PAGE, kinetic, and inhibition experiments. The specific activities of the purified enzymes were similar, but the purification yield of the GZ population (31.54%) was the lowest. SDS-PAGE analysis showed only one band at approximately 23 kDa for these four populations. Kinetic analyses showed that the affinities of the purified GSTs from the GZ and YN populations for 1-chloro-2.4-dinitrobenzene (CDNB) were much higher than those of GSTs from the other two populations, whereas the HN population had the highest catalytic capability in terms of V(max) value. The optimum temperature for CDNB conjugation was 37 °C and the optimum pH was 7.5 in all four populations. Inhibition kinetics showed that ethacrynic acid, diethyl maleate, tetraethylthiuram disulfide, curcumin, bromosulfalein, and β-cypermethrin had excellent inhibitory effects on GSTs in the four populations of B. dorsalis, but the low inhibitory effects of malathion and avermectin did not differ between populations. These results suggest that GSTs may have a role in detoxification of β-cypermethrin in B. dorsalis.     

Genetic relationships between Indians and their neighboring populations

Using gene frequency data for 18 protein and blood group loci, we studied the genetic relationships of four Indian subcontinent populations (peoples from Punjab, Gujarati, Andhra Pradesh, and Bangladesh) with their neighboring populations (Iranians, Afghans, Sinhalese in Sri Lanka, Nepalese, Bhutanese, Malays, Bataks in northern Sumatra, and Chinese). The results obtained indicate that the four Indian subcontinent populations and the Sinhalese are genetically closer to Iranians and Afghans (Caucasoid) than to the other neighboring Mongoloid populations. Genetic distance analysis shows a clear-cut dichotomy between the Caucasoid and Mongoloid populations.     

湖北四个地区草地贪夜蛾田间种群的杀虫剂敏感性及靶标突变检测

【目的】测定湖北草地贪夜蛾田间种群对4种杀虫剂的敏感性,并对杀虫剂靶标Ace-1,VGSC和RyR的基因型和突变频率进行检测,以明确湖北草地贪夜蛾田间种群药剂敏感性现状,进而指导田间科学用药。【方法】采集湖北黄冈、武穴、咸宁和荆州4个地区玉米田中的草地贪夜蛾幼虫,采用浸叶法测定其对氯虫苯甲酰胺、乙基多杀菌素、茚虫威和甲维盐4种杀虫剂的敏感性;提取4个种群80头个体的单头总RNA合成cDNA,利用特异性引物进行PCR扩增,获得目的基因片段,根据序列比对和测序峰图分析,确定Ace-1,VGSC和RyR的基因型和靶标突变位点的突变频率。【结果】生测结果表明,湖北这4个田间种群的草地贪夜蛾幼虫对氯虫苯甲酰胺、乙基多杀菌素、茚虫威和甲维盐均比较敏感,敏感性从高到低依次为:甲维盐乙基多杀菌素氯虫苯甲酰胺茚虫威。分子检测结果表明,湖北草地贪夜蛾这4个田间种群Ace-1基因在A201S, G227A和F290V位点均存在抗性杂合突变,且在F290V位点检测到抗性纯合突变,而VGSC和RyR两个基因均没有检测到靶标位点突变。【结论】湖北草地贪夜蛾4个田间种群对氯虫苯甲酰胺、乙基多杀菌素、茚虫威和甲维盐这4种杀虫剂均较敏感,但这4个草地贪夜蛾田间种群均携带有对有机磷和氨基甲酸酯类杀虫剂的抗性基因,存在潜在的抗性风险,田间防治建议少用或不用该类杀虫剂,同时需要进一步加强抗性监测工作。     

利用微卫星分子标记分析四个中华绒螯蟹群体的遗传多样性

利用本实验室克隆的16个和国际上发表的8个微卫星标记,对4个中华绒螯蟹群体(江苏、安徽、辽宁、天津)的遗传多样性进行检测。所检测到的扩增片段长度为80—445bp,在群体间扩增出2—10个等位基因,共计155个等位基因,平均等位基因6.458个。4个中华绒螯蟹群体的平均有效等位基因数(Ne)为4.3491—4.7234,平均观察杂合度(Ho)为0.5690—0.6722,平均期望杂合度(He)为0.7238—0.7546,并通过基因型的P值,确定了7个座位处于Hardy-Weinberg平衡;同时对4个群体的遗传距离进行了估算,聚类分析结果表明,安徽、江苏、天津聚为一支,属于长江河蟹类型,辽河种群单独聚为一支。     

Genetic studies in south Balkan populations

Within a study of the genetics of Balkan populations, four DNA-STR systems and 19 classical markers were examined in seven samples: Romanians (two groups), Albanians, Greeks and Aromuns (three groups). The results for the DNA-STR systems have been compared with data from the literature. The results show four clear separated groups: sub-Saharan black populations, North-African, Japanese and European populations. The large Balkan populations, except the Greek sample, are genetically more homogenous than the Aromun populations. A second Neighbor-joining tree based on all 23 analyzed systems, show a particular trend of the Aromun groups, which indicates a particular genetic structure.     

The historical differentiation process inHemerocallis middendorfii (Liliaceae) of Japan based on restriction site variations of chlorplast DNA

Chloroplast DNA restriction site variation inHemerocallis middendorfii Trautv. & Meyer was investigated to deduce the historical differentiation process that had taken place in populations among three districts Hokkaido, Honshu and the Island of Tobishima in Japan as distinct from the morphological data. The populations selected were eight in total, consisting of two populations from Honshu, one each from the Islands of Sado and Tobishima and four from Hokkaido. Twelve endonuclease restriction enzymes were used. Six restriction site mutations were found among the populations investigated. A single, most parsimonious phylogenetic tree is generated, and revealed that the four populations of Hokkaido and two populations of the Islands of Sado and Tobishima are monophyly, respectively.     

梅花鹿的微卫星多态性及种群的遗传结构

梅花鹿是我国极度濒危的鹿科动物,其野生种群已濒临灭绝。为了探讨我国野生梅花鹿的保护和管理对策,我们选用了16 个微卫星位点检测来自东北、四川、江西和浙江种群的122 份样品,以此分析我国野生梅花鹿种群的遗传多样性和遗传结构。费希尔确切性检验表明,四个种群中均存在偏离哈迪- 温伯格平衡的现象。与其它的濒危动物相比,中国梅花鹿有着相对较高的遗传多样性:每个位点的平均等位基因数为4 个,平均期望杂合度为0. 559。四个种群中,东北种群拥有最高的平均等位基因数(n = 3. 688),东北种群、四川种群、江西种群以及浙江种群的平均期望杂合度分别为0. 584,0. 477,0. 585 和0.589,它们之间不存在显著的差异。同时,利用逐步突变模型、双相突变模型和无限等位基因突变模型检测了种群的瓶颈效应,结果表明:除四川种群外,其他种群在近期内都经历过遗传瓶颈。费希尔确切性检验及配对样品F ST 的结果均表明:四个梅花鹿种群间存在显著的遗传分化(P < 0. 001)。因此,我们建议将我国梅花鹿的野生种群划分为4 个管理单元进行保护和
管理。     

Effect of zinc on four populations and two generations of Gammarus pulex (L.)

1. The amphipod Gammarus pulex (L.) is increasingly used in toxicity assessments and is usually obtained from wild populations. Interpopulation variability in response to toxicants may be due to genetic or phenotypic differences and could be large in wild-caught organisms exposed to different environmental conditions. This paper describes an investigation designed to assess the extent of lethal and sublethal variability between four different G. pulex populations when exposed to zinc, and to determine whether differences observed in the parental generation were also apparent in offspring bred in the laboratory. 2. The mortality of G. pulex from one of the four field-caught populations (Crags Stream) was significantly lower than for animals from the other three populations for the first 2 days of exposure. After 6 days’ exposure the LC₅₀ values for all four populations did not differ significantly, and were approximately 1.0 mg Zn 1-^?1. Sublethal effects on feeding rate after 6 days’ exposure were also similar for all four populations (feeding rate EC₅₀ approximately 0.5 mg Zn 1-^?1). 3. Lethal effects on the F₁ generation were similar among the four populations, in contrast to the short-term differences observed in the parental generation. These results suggest that interpopulation differences in zinc tolerance in G. pulex are short-lived, and phenotypically rather than genetically based.     

云南四个瓜实蝇地理种群的遗传关系分析

对云南个不同地理区域的瓜实蝇种群(Bactrocera cucurbitae)共23个个体的线粒体DNA细胞色素b基因中的部分序列进行测定和分析,并以桔小实蝇(B.dorsalis)、番石榴实蝇(B.correct)和南瓜实蝇(B.tau)为外群种构建了不同单倍型的N-J分子系统树.在获得的26bp序列中,A+T含量约占65.0%,有个多态位点,无任何碱基插入和缺失.这些位点共定义5种单倍型,其中一种为共享单倍型.对个瓜实蝇地理种群进行Fst值和基因流动统计,Fst值为0.16667～0.20000(P＞0.05),Nm值为2.00～2.50.5种单倍型共形成了3个聚类簇.可以认为,个地理种群间均存在一定程度的遗传分化,但分化程度不高,导致遗传分化的主要因素是地理隔离,而种群遗传分化程度低与瓜实蝇所在环境条件相似有关.     

Integral evaluation of the population variability of human behavioral markers

In eight human populations with different extent of isolation and different ethnic belonging, four groups of cues have been studied: Mendel and anthropogenetic markers, anthropometry, neurodynamics and psychodynamics. Integral estimates are obtained of phenotypic and genetic correlation of groups of anthropometric, neurodynamic and psychodynamic cues in examined populations. Their values vary significantly in different populations; in isolates they are higher than in heterogeneous populations. Multidimensional dispersion analysis of the studied groups of cues allows to establish significantly higher intrapopulation variability than interpopulation one (about 14%). The revealed interpopulation differences are presented in the form of generalized values of phenotypic and genetic resemblance of examined populations by four groups of cues.     

Aggressiveness and Reproduction of Four Meloidogyne arenaria Populations on Soybean

Aggressiveness and reproduction differed among four geographical populations of M. arenaria on six soybean cultivars in field microplots. These differences were consistent over 3 years. The populations did not differ in virulence; i.e., population by cultivar interactions were not significant. Perineal pattern morphology, the North Carolina differential host test, chromosome counts of immature oocytes, and esterase phenotypes confirmed that the four populations were M. arenaria. Three populations were host race 2 and one population was host race 1.