甜菜属厚皮菜SWTY-1细胞质VNTRs多态性分析

利用数目可变串联重复序列(Variable Number of Tandem Repeats,VNTRs)微卫星标记方法,对重庆厚皮菜甜菜材料SWTY-1群体中100个单株的细胞质线粒体DNA片段中TR2位点VNTRs片段多态性进行分析。结果显示97个单株线粒体TR2位点微卫星串联重复序列均为3拷贝,与普通糖甜菜一致;3个单株线粒体TR2位点微卫星串联重复序列为6拷贝,发现甜菜属厚皮菜细胞质TR2位点VNTRs存在多态性,在该群体中发现了不同于甜菜栽培种新的细胞质单株。对该群体材料100个单株的抽薹及结籽进行观测,结果显示微卫星串联重复序列为6拷贝的变异植株中2个单株花期未抽苔开花,1株抽苔晚未形成正常种子;细胞质TR2位点VNTRs片段拷贝数为3的植株中2个单株未能正常抽薹,其他植株均正常抽薹结籽。     

竹亚科lea3基因的进化分析

选取竹亚科中两个超族、六个族和三个亚族的10个竹种为材料,分别是泰竹、凤尾竹、青皮竹、大叶慈、慈竹、野龙竹、毛竹、香竹、苦竹、菲白竹,分离克隆了它们的lea3基因,并将它们与外类群物种水稻进行序列比对和进化分析。结果发现在分支模型与分支位点模型的检测中,不同竹种所含lea3基因承受了不同的正选择压力,清除选择作用在lea3基因编码区中占主导地位（ω<1）。在位点模型的检测中,共检测出了18个显著性正选择位点,占总氨基酸数目的111%。对这18个显著性正选择位点进行定位后,发现其中的15个位于11个氨基酸串联重复序列附近。这说明lea3基因中的11个氨基酸串联重复序列区比基因其它区域更容易受自然选择作用影响。同时,在位点模型检测结果的基础上,通过对强烈清除选择位点的定位,发现在11个氨基酸串联重复序列区内存在一长段无强烈清除位点的序列区。     

大卫鼠耳蝠线粒体控制区串联重复序列变异

中国特有种大卫鼠耳蝠线粒体D-loop区串联重复序列以81bp为重复单元,重复3～7次。54%的个体具有4个串联重复序列,与5～7个串联重复序列的现有模式具有较大的差异。重复单元的遗传差异受所在位次影响,具有明显的家族性或区域性特点。串联重复序列和相对保守的第一重复单元构建的ML树均形成了3个明显的分支,分别定名为东南区、西南区和南方区。线粒体重复序列区域间的差异暗示其可能经历了多次进化,并以东南区变异最为显著。     

应用PCR技术对DMD患者进行缺失检测与产前基因诊断

运用聚合酶链式反应(polymerasechainreaction,PCR)技术对3个Duchenne型肌营养不良症(DMD)家系中的患者进行dystrophin基因内9个外显子缺失检测,在2个家系中检测到外显子45、48、51缺失,同时运用PCR技术扩增位于dystrophin基因内内含子短串联重复序列,对非缺失型DMD家系进行了产前诊断,胎儿为正常女性.dystrophin基因外显子缺失检测方法快速、敏感、准确,可在临床推广中应用;短串联重复序列(STR)多态性分析方法可用于DMD家系的产前基因诊断和携带者检出.     

SV40 PolyA序列及其AATAAA信号对上游GFP基因表达及转录终止的影响

SV40 PolyA(猴空泡病毒PolyA,简称PolyA)序列是有转录终止作用和使转录的mRNA添加PolyA尾的DNA序列(240 bp),含有AATAAA六核苷酸多腺苷化信号(Polyadenylation signal)。在pEGFP-C1质粒的GFP基因下游插入14个同向串联的Alu序列(Alu14),构建pAlu14质粒,瞬时转染HeLa细胞,用Northern blot检测和荧光显微镜观察GFP RNA和GFP蛋白表达,发现Alu串联序列强烈抑制GFP基因表达,该序列没有转录终止作用产生高分子量GFP融合RNA。又在pAlu14质粒GFP基因和Alu串联序列之间按正、反方向插入PolyA序列及去除AATAAA信号的PolyA序列,插入的这些PolyA序列均能部分解除Alu14对GFP基因的抑制作用;去除AATAAA信号的PolyA正、反序列仍然引起转录终止。将PolyA反序(PolyAas)分为4段每段60 bp,中间的2段分别称为2F2R和3F3R,将2F2R或3F3R插在pAlu14质粒的Alu串联序列的上游,随着插入2F2R片段拷贝数的增加转录的GFP融合RNA的分子量增加;2F2R的下游如果依然是2F2R那么2F2R可以支持转录延伸,如果2F2R下游是Alu串联序列则2F2R导致转录终止。无论插入一个3F3R或插入64个3F3R,均产生低分子量GFP RNA。     

XNP基因内多态基因座筛选及其多态性分析

从XNP基因内部筛选多态性较强的多态基因座,为连锁分析和间接诊断奠定基因,通过核酸同源性分析获得含有XNP基因的基因组克隆,并通过对比分析cDNA与基因组DNA的对应关系确定基因的非外显子序列,利用BCMSearch Launcher程序从中筛选短串联重复序列,采用PCR扩增技术和聚丙烯酰胺凝胶电泳方法,对所筛选出的短串联重复序列进行多态性分析,结果从XNP基因内筛选出5个短串联重复序列,多态性分析表明,其中的2个短串联重复序列（XNPSTR1和XNPSTR4）具有多态性,在100名无血缘关系的女性中,分别观察到4和11个等位基因,杂合度分别为47%和70%,XNPSTR1位于XNP基因的3′端,XNPSTR4位于第10内含子,结论是：从XNP基因内筛选出两个多态位点,可用于XNP基因的连锁分析和间接基因诊断。     

辽东湾斑海豹(Phoca largha)线粒体D-loop区异质型研究初探

采用PCR技术和DNA克隆测序技术,随机测定了3头斑海豹mtDNA控制区(D-loop区)csn-3上、下游1000bp左右的序列,每头斑海豹任选14个克隆菌斑进行测序,结果所得序列均无重复,得到42个单倍型.结合GenBank已发表的斑海豹mtDNA控制区序列(Phoca largha,AM181031),通过Clusta1X1.83、MEGA3.1和FastPCRv3.6等生物信息学软件进行序列比对,发现我国珍稀保护动物斑海豹个体内线粒体DNA(mtDNA)的控制区CSB-3之后存在异质型现象,且存在数目不等的串联重复序列.从分子水平进行了不同类型重复序列变化规律的研究,初探了mtDNA控制区异质型在斑海豹中的存在情况.     

鸮形目4种鸟类线粒体调控区全序列的测定与比较研究

利用Long-PCR和Primer Walking的方法对鸮形目的短耳鸮、长耳鸮、纵纹腹小鸮、灰林鸮4种鸟类的线粒体调控区进行了全序列测定。结果表明：短耳鸮的调控区跃度为3290bp;长耳鸮为2848bp;纵纹腹小鸮为2444bp;灰林鸮为1771bp。短耳鸮的调控区长度是4种鸮中最大的,并且是目前已知最大的鸟类线粒体调控区。这4种鸮类调控区的基本结构和其他鸟类相似,按照碱基变化速率的不同可以分为3个区：碱基变化速率较快的外围区域Ⅰ、Ⅲ和保守的中间区域Ⅱ。这4种鸟类调控区的3’端均存在大量的串联重复序列,短耳鸮为126bp单元重复7次和78bp单元重复14次;长耳鸮为127bp单元重复8次和78bp单几重复6次;纵纹腹小鸮有3个重复单元,分别为89bp单元重复3次、77bp单元重复4次和71bp单元重复6次;灰林鸮仅有1个单元的串联重复为78bp重复5次。调控区中串联重复序列可能是由链的滑动错配产生,另外这些重复序列都能形成热力学稳定的多重茎环二级结构,而且在重复序列中还发现一些保守基序,这说明重复序列可能具有一定的生理功能,影响调控区的调重控功能从而影响线粒体基因组的复制和转录。     

SV40PolyA片段串联拷贝数目影响GFP报告基因表达

Alu元件（约280bp）是人类基因组中的重要重复序列,串联Alu呈长度依赖性下调GFP报告基因表达,在Alu串联序列上游正向或反向插入SV40PolyA（简称PolyA,240bp）,解除Alu串联序列对GFP基因的抑制作用.PCR法扩增PolyA反序（PolyAas）不同位置的60bp片段,插入pAlu14质粒（14个Alu正向串联插入pEGFP-C1）的GFP基因和Alu14之间,瞬时转染HeLa细胞,通过荧光显微镜观察和Northern检测,1F1R（PolyAas5′端第1个60bp片段）和4F4R（自PolyAas5′端计算第4个60bp片段）不能活化基因;2F2R和3F3R（PolyAas中间的2段）可以解除Alu14对GFP基因的抑制作用.将2F2R和3F3R各自反复首尾串联,分别插入pAlu14质粒GFP基因和Alu串联序列之间,瞬时转染HeLa细胞,用插入4个2F2R的pAlu28,插入4个3F3R的pAlu18,插入4个3F3R的pAlu28作长度对照,以排除由于插入片段长度增加可能对结果造成的干扰,发现2～4个拷贝的2F2R和3F3R活化基因作用高于一个拷贝的同样片段,但是多于8拷贝以后,活化GFP基因作用减弱.本实验证明,SV40 PolyAas至少含有两段活化基因序列,活化基因序列（2F2R,3F3R）的最适活化基因条件需要合适的拷贝数.     

丝状支原体山羊亚种PG3株的全基因组序列测定与分析

【目的】全面了解丝状支原体山羊亚种PG3株的全基因组序列信息,寻找该病原体的主要保护性抗原基因。【方法】利用高通量Illumina Hi Seq 2000测序技术对丝状支原体山羊亚种PG3株的全基因组进行测序与拼接,借助软件和数据库对全基因组序列所承载的遗传信息进行注释和分析。【结果】丝状支原体山羊亚种PG3株基因组大小为1 025 065 bp,G+C%为23.6%,预测含有846个编码基因。根据COG分类和KEGG代谢通路分类,基因组中绝大多数基因主要与蛋白翻译、核糖体结构与合成、DNA复制与修复、糖代谢和环境信号传递与转换方面有关。该菌株具有丝状支原体山羊亚种特有的麦芽糊精/麦芽糖代谢途径。与Mmc str.95010的基因组的比对结果显示二者具有良好的共线性关系。在基因组中发现3个串联排列的可变表面脂蛋白基因,即GL000459、GL000461和GL000462。【结论】获得丝状支原体山羊亚种PG3株的全基因组序列,分析基因组基本特征,初步解析3个串联排列的可变表面脂蛋白基因,为进一步研究支原体可变表面脂蛋白的功能和研制生物工程疫苗奠定基础。     

Genetic diversity and ecological relationships of marsh frog populations in Israel

Summary Allozymic variation in proteins encoded by 28 loci was analyzed electrophoretically in 340 mostly adult specimens representing 11 populations, 8 central and 3 isolated, of aquatic marsh frogs, Rana ridibunda in Israel, along a north-south transect of generally increasing aridity. In addition, geographic variation in 3 morphological variables of 144 frogs and in vertebral stripe color polymorphism of 262 frogs were also studied. The results indicate that. (a) Of the 28 loci examined, 12 (= 43%) are largely monomorphic in all populations; out of the remaining loci, 6 were locally and weakly polymorphic and 10 regionally and strongly polymorphic. (b) No fixation of alternative alleles was found in any of the 28 loci and 11 populations studied. The commonest allele predominated across all populations, central as well as isolates, (c) Clinal patterns associated with increasing aridity southwards and eastwards occurred in polymorphism, P; heterozygosity, H; and in allele frequencies of Esterase-1, Xanthine dehydrogenase, Aldehyde oxidase and Albumin. (d) In the 3 estimates of genie variation, mean number of alleles per locus, A, mean proportion of polymorphic loci per population, P, and heterozygous loci per individual, H, marsh frogs displayed average estimates of genetic variation. The 3 estimates were: A =1.14 (range, 1.18–1.57); P = 0.33 (range, 0.14–0.54): H = 0.069 (range, 0.032–0.094). (e) Central populations harbored distinctly more genic variation than isolated populations. (f) Genic similarity between populations was high. (g) Significant deviations from Hardy-Weinberg equilibrium were found in 8 out of 11 populations involving 8 loci, (h) P, H, and allozymic variation in several gene loci were significantly correlated and predictable by environmental variables, primarily those related to water and temperature. (i) A significant amount of morphological variation was found between localities for body length, foot length, and weight in both sexes. Body weight in females was negatively correlated with temperature; and all three morphological variables in females were predicted significantly by a combination of temperature and humidity. (j) The three vertebral stripe color phenotypes, gray, green and red occurred in the following frequencies: 0.59, 0.24, 0.17, respectively. The red morph increased clinally southwards and was significantly correlated with most temperature and water variables. The geographic variation in both the green and red morphs was predicted significantly by climatic variables, both colors blending with local substrates.The spatial patterns and environmental correlates of genetic and morphological variation in Rana ridibunda in Israel suggest that (i) protein polymorphisms are at least partly adaptive and that part is moulded by natural selection rather than by stochastic processes or neutrality; (ii) the environmental variation model seems to be a good predictor of genetic variation in marsh frogs; (iii) body size varies adaptively, presumably determined primarily through thermoregulation; (iv) the spatial pattern of the color polymorphism seems to be adaptively selected by at least two factors: visual predation and climatic determinants.     

Polymorphisms of HLA-DRB1, -DQA1 and -DQB1 in Inhabitants of Astana,the Capital City of Kazakhstan

Background

Kazakhstan has been inhabited by different populations, such as the Kazakh, Kyrgyz, Uzbek and others. Here we investigate allelic and haplotypic polymorphisms of human leukocyte antigen (HLA) genes at DRB1, DQA1 and DQB1 loci in the Kazakh ethnic group, and their genetic relationship between world populations.

Methodology/Principal Findings

A total of 157 unrelated Kazakh ethnic individuals from Astana were genotyped using sequence based typing (SBT-Method) for HLA-DRB1, -DQA1 and -DQB1 loci. Allele frequencies, neighbor-joining method, and multidimensional scaling analysis have been obtained for comparison with other world populations. Statistical analyses were performed using Arlequin v3.11. Applying the software PAST v. 2.17 the resulting genetic distance matrix was used for a multidimensional scaling analysis (MDS). Respectively 37, 17 and 19 alleles were observed at HLA-DRB1, -DQA1 and -DQB1 loci. The most frequent alleles were HLA-DRB1*07:01 (13.1%), HLA-DQA1*03:01 (13.1%) and HLA-DQB1*03:01 (17.6%). In the observed group of Kazakhs DRB1*07:01-DQA1*02:01-DQB1*02:01 (8.0%) was the most common three loci haplotype. DRB1*10:01-DQB1*05:01 showed the strongest linkage disequilibrium. The Kazakh population shows genetic kinship with the Kazakhs from China, Uyghurs, Mongolians, Todzhinians, Tuvinians and as well as with other Siberians and Asians.

Conclusions/Significance

The HLA-DRB1, -DQA1and -DQB1 loci are highly polymorphic in the Kazakh population, and this population has the closest relationship with other Asian and Siberian populations.     

Analysis of genetic diversity in the endangered Hucho taimen from China

Hucho taimen are listed as endangered in China. The population size has declined recently, prompting an increase in the level of listing from grade three in 2002 to grade five in 2006. We analyzed the genetic diversity of wild populations using 17 microsatellite markers to establish a scientific basis for conservation of this species. We collected tissue samples from four populations in the Heilongjiang River basin: Huma River (HM), Hutou (HT), Haiqing (HQ), and Zhuaji (ZJ). A total of 21 loci were amplified, 18 of which were polymorphic. The number of alleles per locus ranged from 2 to 9 (mean: 4.1905). There were 13 highly polymorphic loci and 5 moderately polymorphic loci. Analysis of five genetic diversity parameters (Na, Ne, Ho, He, and PIC) suggested moderate levels of diversity within the populations. The populations were ranked HT > HQ > ZJ > HM, but the differences in diversity were not statistically significant (P > 0.05). A comparison of variation among all four populations suggested Hardy–Weinberg disequilibrium at 20% of the loci. Genetic differentiation (Fst) was 0.0644 and the gene flow among populations was estimated at 3.36 individuals per generation. The majority of diversity (93.88%) occurred among individuals within a population. In contrast, relatively little (6.12%) of the genetic diversity was distributed between the populations. An analysis of genetic differentiation and genetic distance between pairs of populations revealed that both parameters were higher in comparisons of the HM population to the HT, HQ, and ZJ populations than among the three latter populations. This suggests that the HM population has a distinct genetic structure. We hypothesize that habitat degradation and excessive fishing, not low genetic diversity, has caused the decline in H. taimen populations. However, this species should be protected from further declines in genetic diversity.     

Patterns of Gene Variation in Central and Marginal Populations of DROSOPHILA ROBUSTA

The central and marginal populations of D. robusta differ greatly in the level of inversion polymorphism; the marginal populations are monomorphic or nearly so and the central populations are highly polymorphic. This paper presents the frequencies of alleles at forty gene loci in various populations of D. robusta, studied by electrophoresis of proteins and enzymes. Population samples were obtained from eight widely separated populations of D. robusta which included the central, the extreme marginal and the intervening populations between the center and the margins. We find that the proportion of polymorphic loci and average heterozygosity per individual is slightly higher in the marginal populations than the central populations. In D. robusta on an average, 39% of the loci are polymorphic and the average proportion of loci heterozygous per individual is 11%. A breakdown of loci in three categories, viz, hydrolytic enzymes and some other enzymes, larval proteins and glycolytic and Kreb's cycle enzymes, shows that in all populations the level of polymorphism is highest in the hydrolytic enzymes, intermediate in larval proteins and least in the glycolytic and Kreb's cycle enzymes. On the average, the proportion of loci heterozygous per individual for three groups of loci is: hydrolytic enzymes and others (.164), larval proteins (.115) and glycolytic and Kreb's cycle enzymes (.037). We also observe that in all populations the level of polymorphism on the X chromosome is far less than the expected 38%; in salivary gland cells the euchromatic length of the X chromosome is 38% of the entire genome. Lower levels of polymorphism for the X chromosome loci are explained due to low probability of balanced polymorphisms for the X-linked loci since the conditions for establishment of balanced polymorphism for X-linked loci are more restrictive than for the autosomal loci.-The polymorphic loci can be grouped according to pattern of allele frequencies in different populations as follows: (1) The allele frequencies are similar in all populations at the XDH, Pep-1 and Hex-1 loci. (2) The alleles at the Est-1, Est-2, Amy loci and the AP-4(1.0) and the LAP-1(.90) alleles show north south clinal change in frequency. (3) There is north south and east west differentiation at the Pt-5, Pt-8 and Pt-9 loci and the allele AP-4(.81). (4) Polymorphism at loci such as Fum, B.Ox, Hex-8, Pep-2 and Pep-3 are restricted to only one or two of the populations. (5) Allele frequencies at the MDH and ODH loci fluctuate between populations. (6) Allele frequencies at many polymorphic loci such as Est-1, Est-2, LAP-1, AP-4, Pt-5, Pt-8, Pt-9, Pt-16, MDH, Fum change clinally within a gene arrangement. The pattern of gene variation in D. robusta is very complex and cannot be easily explained due to migration of neutral alleles between once-isolated populations or to semi-isolation of neutral alleles. The observations of the pattern of allele variation in different populations, high levels of polymorphism in the marginal populations which have small population size and low levels of polymorphism of the X chromosome loci all support the argument in favor of balancing selection as the main mechanism for the maintenance of these polymorphisms. Environmental factors must play a role in the maintenance of a great deal of these polymorphisms, since we observe clinal allele frequency changes even within a given inversion type.     

Genetic diversity of wild emmer wheat in Israel and Turkey

Summary Allozyme variation in the tetraploid wild emmer wheat, Triticum dicoccoides, the progenitor of all cultivated wheats, was studied for the proteins encoded by 42 gene loci in 1815 plants representing 37 populations - 33 from Israel and 4 from Turkey - sampled in 33 localities from 1979 to 1987. The results showed that: (a) 6 loci (14%) were monomorphic in all populations, 15 loci (36%) were locally polymorphic, and 21 loci (50%) were regionally polymorphic. These results are similar to those obtained earlier on 12 Israeli populations. All polymorphic loci (except 4) displayed high local levels of polymorphism (>/ 10%). (b) The mean number of alleles per locus, A, was 1.252 (range: 1.050–1.634); the proportion of polymorphic loci per population averaged 0.220 (range: 0.050–0.415); genic diversity, He, averaged 0.059 (range: 0.002–0.119). (c) Altogether there were 119 alleles at the 42 putative loci tested, 114 of these in Israel, (d) Genetic differentiation was primarily regional and local, not clinal; 70% of the variant alleles were common (>/ 10%) and not widespread, but rather localized or sporadic, displaying an archipelago population genetics and ecology structure. The coefficients of genetic distance between populations were high and averaged D = 0.134; range: 0.018–0.297, an indication of sharp genetic differentiation over short distances, (e) Discriminant analyses differentiated Israeli from Turkish populations, and within Israel, between central and 3 marginal regions, as well as between different soil-type populations, (f) Allozymic variation comprised 40% within and 60% between populations, (g) Gametic phase disequilibria were abundant, their number being positively correlated (r_s = 0.60, P<0.01) with the humidity, (h) Multilocus organization was substantive, also positively correlated with humidity, (i) Allozyme diversity, overall and at single loci, was significantly correlated with, and partly predictable by, climatic and edaphic factors, (j) The distrubition of the significant positive and negative values and the absence of autocorrelations in the correlogram revealed no similar geographic patterns across loci, eliminating migration as a prime factor of population genetic differentiation. These results suggest: (I) during the evolutionary history of wild emmer, diversifying natural selection, through climatic and edaphic factors, was a major agent of genetic structure and differentiation at both the single and multilocus levels; (II) wild emmer harbors large amounts of genetic diversity exploitable as genetic markers in sampling and abundant genetic resources utilizable for wheat improvement.     

中华稻蝗四个种群的遗传分化

采用水平淀粉凝胶电泳技术研究中华稻蝗(Oxya chinensis)四个种群的12个基因座位,探讨其遗传分化.这四个种群分别采自内蒙古呼和浩特、山西代县、山西太原和陕西西安.Ck和Mdh-2在四个种群中均为单态,其余的基因座位至少在一个种群内有两个以上的等位基因;在Ldh和Mdh-1的等位基因频率呈现梯度分布趋势.多态基因座位百分率(P)和平均每个基因座位的等位基因数目(A)分别为58.3%-66.7%和2.2-2.8,平均杂合度为Ho=0.173-0.240.除Gpi,Hk-2,Idh,Ldh和Mdh-1在部分蝗虫种群符合Hardy-Weinberg平衡外,其余绝大多数基因座位的基因型频率显著偏离Hardy-Weinberg平衡.四个种群间FST平均值不存在显著差异(FST=0.0510,P＞0.05),结合高的Nei's遗传一致度(I＞0.97)可知,种群之间遗传分化不明显.我们认为人类的农业活动可能促进了种群间的基因交流,从而降低了分化程度[动物学报50(2)187-192,2004].     

Origins and colonization history of pandemic Vibrio parahaemolyticus in South America

The dynamics of dissemination of the environmental human pathogen Vibrio parahaemolyticus are uncertain. The O3:K6 clone was restricted to Asia until its detection along the Peruvian coasts and in northern Chile in 1997 in phase with the arrival of El Niño waters. A subsequent emergence of O3:K6 strains was detected in austral Chile in 2004. The origin of these 1997 and 2004 population radiations has not yet been conclusively determined. Multiple loci VNTR analysis using seven polymorphic loci was carried out with a number of representative strains from Asia, Peru and Chile to determine their genetic characteristics and population structure. Asian and Chilean subpopulations were the most genetically distant groups with an intermediate subpopulation in Peru. Population structure inferred from a minimum‐spanning tree and Bayesian analysis divided the populations into two genetically distinct groups, consistent with the epidemic dynamics of the O3:K6 clone in South America. One group comprised strains from the original Asiatic population and strains arriving in Peru and Chile in 1997. The second group included the remaining Peruvian Strains and Chilean strains obtained from Puerto Montt in 2004. The analysis of the arrival of the O3:K6 clone at the Pacific coasts of South America has provided novel insights linking the origin of the invasion in 1997 to Asian populations and describing the successful establishment of the O3:K6 populations, first in Peru and subsequently in the South of Chile owing to a possible radiation of Peruvian populations.     

Genetic diversity of six populations of Atractomorpha sinensis and Atractomorpha peregrina in Shanxi Province, China

Ten enzymes (AAT,CK,G3PDH,HEX,IDH,LDH,MDH,ME,PGI,PGM)were examined using horizontal starch gel electrophoresis to estimate the levels of genetic variation within and among six natural populations of two grasshopper species Atractomorpha sinensis and A.peregrina from Shanxi,China.The collecting sites were geographically distant from each other from south to north:Quwo district,Linfen city;Xiangyuan county,Changzhi;Jinyuan district,Taiyuan city;Yuanping county,Xinzhou city and Fanshi county of Xinzhou.A.sinensis showed 43 alleles at 16 loci but A.peregrine showed 39 alleles at 15 loci (ldh-1 was deficient).The zymograms showed that some common alleles were shared at several loci in these two species (Aat-1-b,Aat-2-b,G3pdh-a,Ck-1-b and Ldh-b).However,Hex-1-a,Hex-2-a,Hex-3-a,Idh-2-b,Mdh-2-b,Mdh-1-f Pgi-b,Pgm-b had common alleles in A.sinensis and Hex-1-b,Hex-2-b,Hex-3-b,Idh-2-a,Mdh-2-a,Mdh-1-d,Pgi-a,Pgm-c were of high frequency in A.peregrine instead.Most of the observed genotype frequencies were found to significantly deviate from the Hardy-Weinberg expectations in both species.A tendency of clinal distribution of allele frequency was observed at three loci.The frequency of the moderately migrating allele Me-c (0.318-0.740)in A.peregrina,Hex-1-a (0.800-1.000)and Ldh-b (0.487-0.750)in A.sinensis demonstrated increased frequency from north to south.Such tendency suggests that the allele frequency in these three loci may be correlated with the species'geographic distributions.A.sinensis showed higher genetic diversity than A.peregrina as indicated by higher mean number of alleles per locus (A=1.9-2.3 in A.sinensis and 1.7-2.2 in A.peregrina),percentage of polymorphic loci (56.3%-68.8%in A.sinensis and 43.8%-56.3%in A.peregrina),and the observed heterozygosities (Ho=0.072-0.096 in A.sinensis and 0.070-0.107 in A.peregrina).The observed heterozygosities of the six populations were all noticeably lower than the Hardy-Weinberg expectations,mostly due to heterozygote deficiency in the populations of both species.The overall mean Fsr were small (FST=0.045,P＞0.05 in A.sinensis populations and 0.087,P＞0.05 in A.peregrina populations).Nei's genetic identity (I)estimates indicate low intraspecific (＞0.95)but higher interspecific (0.377-0.447)genetic diversity.The cluster analysis based on modified Roger's genetic distance (D)showed that the two species were divided into two branches.Both species are of limited dispersal capacity and a moderate geographical barrier might significantly restrict the gene exchange among populations,resulting in accumulation of local genetic differentiations.The A.sinensis populations used in this study were separated from each other by 155.2 to 271.4 km and the A.peregrina populations were separated from each other by 78.8 to 174.9 km with observable physical barriers.The aUozyme data showed only minimal genetic differentiation at population level,most likely as a result of gene exchange.It is reasoned that natural factors and human agricultural activities might have facilitated migration and dispersal for the two species.     

Allozyme polymorphism and phylogenetic relationships in Apis mellifera subspecies selectively reared in Poland and Bulgaria

The genetic variability of honey bee populations of three subspecies selectively reared in Poland (A. m. carnica and A. m. caucasica) and Bulgaria (A. m. macedonica-type rodopica) was studied using isoenzyme analysis of six enzyme systems (MDH-1, ME, EST-3, ALP, PGM and HK) corresponding to 6 loci. All loci were found to be polymorphic in the studied populations. Three alleles were detected at each locus: MHD-1 (MDH65, MDH80 and MDH100), Me (ME90, ME100 and ME106), EST-3 (EST94, EST100 and EST118), ALP (ALP80 ALP90 and ALP100), PGM (PGM80, PGM100 and PGM114) and HK (HK87, HK100 and HK110). The observed and expected heterozygosities (Ho and He) ranged from 0.196 (A. m. macedonica SM) to 0.265 (A. m. carnica MV) and from 0.224 (A. m. macedonica SM) to 0.273 (A. m. carnica GR), respectively. Allele frequencies of all loci were used to estimate Nei's (1972) genetic distance, which was found to range from 0.003 (between A. m. macedonica TR and SM and between A. m. carnica GR and MV populations) to 0.057 (between A. m. macedonica SM and A. m. caucasica populations). The estimated mean F(ST) value from allozyme data was 0.0364. A UPGMA dendrogram was obtained by genetic distance matrix methods; A. m. macedonica (type rodopica), A. m. carnica and A. m. caucasica populations represented different clades.     

西南地区麻疯树天然种群遗传多样性的等位酶变异

为了揭示麻疯树(Jatropha curcas)天然种群的遗传多样性和遗传结构, 采用聚苯烯酰胺凝胶垂直平板电泳技术, 对采自四川、云南、贵州3个省的10个麻疯树天然种群的叶片样本进行了同工酶分析。7个酶系统10个位点的检测结果表明: 麻疯树种群水平上的遗传多样性较高, 每位点平均等位基因数为2.428 6, 多态位点百分率为97.14%, 平均期望杂合度为0.396 4。种群间遗传分化系数为0.041 3, 种群间总的基因流较高, 为5.808 9, 种群间遗传一致度较高(Shannon信息指数为0.921 7- 0.995 3)。非加权类平均法(UPGMA)聚类结果显示, 10个种群的遗传距离与地理距离相关性不显著。麻疯树天然种群具有较低程度的遗传分化、较高的基因流, 种内及种群内多样性丰富, 这为麻疯树优良品种的选育提供了良好的遗传基础。