红色原鸡群体遗传多样性

为了阐明红色原鸡的群体遗传结构,以对其有效保护提供遗传学依据,采用33个微卫星标记对其群体中56个个体进行了PCR-聚丙烯酰胺多态性电泳检测。33个微卫星座位共检测到140个等位基因,所有座位都呈现出多态性,每个座位的等位基因数在2～8个之间,平均每个座位等位基因数4.24个,有效等位基因数3.30个。根据等位基因频率,计算出的群体表观杂合度、期望杂合度及多态信息含量分别为0.7980、0.6506和0.5948。结果表明,红色原鸡群体遗传多样性较丰富。     

秦川牛GHR基因SNPs及其与生长性状关系的研究

利用PCR-SSCP技术研究了136头秦川牛GHR基因第10外显子多态性, 所研究的秦川牛群体GHR基因该座位存在多态性, 发现了A、B、C 3个等位基因, 其基因频率依次为0.5956、0.2905、0.1140, 并且群体处于Hardy-Weinberg平衡状态。对纯合基因型个体进行测序, 测序结果, 该座位存在两个突变位点。通过构建最小二乘线性模型, 分析了生长激素受体基因与生长性状的关系, 表明生长激素受体基因的AB基因型效应在部分生长性状上高于其他基因型, 差异达到显著水平, 提示GHR基因有可能作为秦川牛生长性状的侯选基因。     

茶花鸡群体遗传多样性

茶花鸡是我国具有独特遗传特性的地方家禽品种,为了进一步阐明其群体遗传变异和遗传结构状况,采用了33个家鸡特异性的微卫星标记对该鸡种自然群体中30个个体进行了多态性电泳检测。33个微卫星座位共检测到105个等位基因,所有座位都呈现出多态性,每个座位的等位基因数在2~5个之间,平均每个座位等位基因数3.20个。群体平均杂合度和平均多态信息含量分别为0.612 9和0.527 6。结果表明,茶花鸡自然群体遗传多样性较丰富。     

绵羊微卫星BMS2508和FecB基因的多态及连锁分析

文章分析与绵羊高繁殖力主效基因FecB紧密连锁的微卫星座位BMS2508在高繁殖力绵羊品种(小尾寒羊)和低繁殖力绵羊品种(特克塞尔、多赛特和中国美利奴)中的遗传多态性, 同时探讨该微卫星座位与小尾寒羊FecB基因的连锁不平衡关系。高繁殖力品种小尾寒羊在骨形态发生蛋白受体IB(Bone morphogenetic protein receptor IB, BMPR-IB)基因编码序列第746位碱基处发生了与Booroola Merino绵羊相同的FecB突变(A746G), 而在低繁殖力的特克塞尔、多赛特和中国美利奴绵羊中没有检测到该突变; 小尾寒羊BB、B+、++的基因型频率分别为0.485、0.398和0.117。微卫星座位BMS2508在4个绵羊品种的438个个体中共检测到8个等位基因和15种基因型, 最小等位基因为94 bp, 最大等位基因为116 bp; 小尾寒羊(n = 307)、特克塞尔(n = 45)、多赛特(n = 46)、中国美利奴(n = 40)和BB型(n = 149)、B+型(n = 122)、++型(n = 36)小尾寒羊群体中优势等位基因分别是100 bp、94 bp、94 bp、112 bp、100 bp、100 bp、112 bp, 其频率分别为0.453、0.544、0.802、0.475、0.483、0.439、0.389。连锁不平衡分析显示小尾寒羊FecB基因B等位基因与BMS2508微卫星座位100 bp等位基因之间存在一定的连锁不平衡(D′=0.408), 而+等位基因与BMS2508微卫星座位110 bp和114b p等位基因均存在一定的连锁不平衡(D′=0.513)。     

河西绒山羊DRB3基因外显子2多态性分析

研究采用PCR-SSCP方法检测1 046只河西绒山羊DRB3基因第2外显子的多态性,并克隆、测序群体内变异产生的各等位基因,分析各等位基因间的遗传关系和进化意义。结果表明,河西绒山羊DRB3基因第2外显子表现了18个等位基因(LG001-LG018)控制的31个基因型,LG005为优势等位基因,LG005*005为优势基因型,18个单倍型序列分析发现44个核苷酸多态位点、29个氨基酸多态位点;与GenBank下载序列比对分析结果表明,16个DRB3的等位基因是本研究首次发现;DRB3基因遗传多态指数中,观察杂合度为0.269 6,多态信息含量为0.869 9,有效等位基因数为1.369 1;经χ2适合性检验,该群体偏离了Hardy-Weinberg平衡状态(P<0.05);18个DRB3基因外显子2的单倍型序列NJ系统发育树呈2支分化趋势。研究认为河西绒山羊DRB3基因第2外显子具有丰富的遗传多态性;河西绒山羊DRB3基因最初由2个等位基因突变分化成两大类等位基因。     

甘肃西门塔尔牛甘州类群MSTN基因外显子多态性分析

采用PCR-SSCP方法检测50头甘肃西门塔尔牛甘州类群MSTN基因3个外显子的遗传多态性,并对群体内各等位基因进行测序,旨为探讨西门塔尔牛MSTN基因与肉质性状关联等方面的研究提供理论依据。结果显示,甘肃西门塔尔牛甘州类群MSTN基因3个外显子中,外显子2受B、C等位基因控制,形成BB、CC和BC 3种基因型,基因型频率分别为0.22(11/50)、0.64(32/50)、0.14(7/50);外显子1和外显子3分别受A等位基因与D等位基因控制,形成AA和DD基因型,基因型频率均为1(50/50)。序列分析表明,甘肃西门塔尔牛甘州类群MSTN基因3个外显子中,外显子2在第41 bp处发生了C→T的突变,但并没有导致氨基酸发生改变,属于同义突变;外显子1和3均无突变。统计结果表明,甘肃西门塔尔牛甘州类群MSTN基因3个外显子中,外显子2为中度多态,其余均无变化。     

鲤鱼微卫星突变速率和模式(英文)

利用150个微卫星分子标记在F1代家系的基因型分析过程中,共有27600个等位基因从亲本向子代传递,其中在5个微卫星座位上检测到6个突变的等位基因。对突变的等位基因数目进行统计分析后得出:鲤鱼平均每个世代每个微卫星座位的突变速率为2.53×10-4。在发现突变的5个位点中,经测序发现,突变序列中插入1个以上的重复单元就导致了突变的发生。这些突变表明,鲤鱼的微卫星突变没有遵循严格的渐变突变模型(stepwise mutation model,SMM)。该文关于鲤鱼微卫星突变速率和模式的研究将会对统计鲤鱼有效群体的统计提供有效参数。     

长江江豚微卫星DNA分离的初步研究

为了开发物种特异性微卫星标记,本文采用一种改良的快速微卫星分离法(FIASCO)从长江江豚(Neophocaena phocaenoides asiaeorientalis)的基因组中筛选得到72条微卫星DNA序列。根据重复单元的排列特点,完美型、非完美型及复合型序列所占的比例分别为58.3%、22.2%和19.5%。选择其中30条序列设计PCR扩增引物,并用12个随机选择的长江江豚样品进行多态性筛选。初步结果表明其中14对引物的扩增产物稳定并且具有多态性;在每个座位上获得2-13个等位基因,平均等位基因数为5.87个;14个微卫星座位的平均观察杂合度(Ho)和期望杂合度(He)分别为0.560和0.709。本研究获得了长江江豚的第一批物种特异性微卫星座位及其扩增引物,这些微卫星标记将在后续的保护遗传学研究中发挥重要作用。       

新疆维吾尔族和哈萨克族人群3个微卫星座位分析

采用基因扫描技术研究了新疆维吾尔族和哈萨克族群体D16S539、D13S317、D7S8203个微卫星位点上的等位基因及基因型分布情况,获得3个基因座的群体遗传学数据。结果表明3个基因位点在两民族中均具有遗传多态性,两民族样本在这3个微卫星位点基因频率分布大致相同。     

应用微卫星标记分析野生中国明对虾的亲权关系

利用5个高度多态性的微卫星座位(Fc04、Fc06、Fc18、Fc24、Fc27),分析了不同年份中建立的10个野生中国明对虾家系中的雌性亲虾及其后代基因型分离的情况,表明每个家系中只有一个雄性野生中国明对虾对子代的遗传有贡献.从其中3个家系的雌性亲虾纳精囊中提取了雄虾精子DNA,微卫星标记显示各家系的子代个体均有一个等位基因与雄性亲虾的基因型相符,且符合孟德尔遗传规律,这为野生中国明对虾雌虾在繁殖季节一对一的繁殖行为提供了遗传学的证据.用UPMGA的方法随机对3个家系的40尾子代个体进行聚类分析,每个家系都能被单独聚成一类.上述工作表明微卫星标记在对虾育种中作为一种有效的亲子关系分析工具,在种群的遗传结构、亲缘关系、繁殖行为等方面具有广阔的应用前景.     

元江鲤种群遗传多样性

选择12对微卫星标记检测了于2011年采集自元江(红河上游中国江段)5个样点192尾鲤的群体遗传多样性.共检测到201个等位基因,每个位点等位基因2-27个.各群体各位点平均等位基因(NA)12.25-14.67个,平均有效等位基因(NE)8.28-9.73个,平均观察杂合度(Ho)o.7765-0.8037,平均期望杂合度(HE)0.7761-0.8080,平均多态信息含量(PIC)0.7534-0.7843.元江鲤种群192个个体各位点NA、NE、Ho、HE、PIC分别为16.50、11.26、0.7927、0.8049、0.7966,种群遗传多样性水平高.元江鲤群体之间遗传分化小,可作为一个种群管理单元进行管理.增殖放流要防止遗传多样性丧失.     

跨种扩增筛选大鳄龟微卫星标记及遗传多样性分析

跨种扩增是一种能够快速、有效地获得物种微卫星标记的方法。本研究利用在近缘种中已发表的微卫星DNA引物,对大鳄龟（Macroclemys temminckii）进行跨种PCR扩增,在合成的69对引物中获得8对具有多态性的微卫星位点。对PCR扩增产物进行统计,得出观测杂合度（H_o）的范围是0.041 7~0.954 5,平均为0.384 8;期望杂合度（H_E）的范围为0.041 7~0.811 8,平均为0.479 1;多态信息含量范围为0.040 0~0.759 2,平均为0.423 2;经过卡方检验后,部分微卫星位点符合哈迪-温伯格平衡。总体来说,这些位点是研究大鳄龟遗传结构的良好分子标记。     

The polymorphism in the promoter region of metallothionein 1 is associated with heat tolerance of scallop Argopecten irradians

Metallothioneins (MTs), a superfamily of cysteine-rich proteins, perform multiple functions, such as maintaining homeostasis of essential metals, detoxification of toxic metals and scavenging of oxyradicals. In this study, the promoter region of a metallothionein (MT) gene from Bay scallop Argopecten irradians (designed as AiMT1) was cloned by the technique of genomic DNA walking, and the polymorphisms in this region were screened to find their association with susceptibility or tolerance to high temperature stress. One insert–deletion (ins–del) polymorphism and sixteen single nucleotide polymorphisms (SNPs) were identified in the amplified promoter region. Two SNPs, − 375 T–C and − 337 A–C, were selected to analyze their distribution in the two Bay scallop populations collected from southern and northern China coast, which were identified as heat resistant and heat susceptible stocks, respectively. There were three genotypes, T/T, T/C and C/C, at locus − 375, and their frequencies were 25%, 61.1% and 13.9% in the heat susceptible stock, while 34.2%, 42.1% and 23.7% in the resistant stock, respectively. There was no significant difference in the frequency distribution of different genotypes between the two stocks (P > 0.05). In contrast, at locus − 337, three genotypes A/A, A/C and C/C were revealed with the frequencies of 11.6%, 34.9% and 53.5% in the heat susceptible stock, while 45.7%, 32.6% and 21.7% in the heat resistant stock, respectively. The frequency of C/C genotype in the heat susceptible stock was significantly higher (P < 0.01) than that in the heat resistant stock, while the frequency of A/A in the heat resistant stock was significantly higher (P < 0.01) than that in the heat susceptible stock. Furthermore, the expression of AiMT1 mRNA in scallops with C/C genotype was significantly higher than that with A/A genotype (P < 0.05) after an acute heat treatment at 28 °C for 120 min. These results implied that the polymorphism at locus − 337 of AiMT1 was associated with the susceptibility/tolerance of scallops to heat stress, and the − 337 A/A genotype could be a potential marker available in future selection of Bay scallop with heat tolerance.     

Analysis of STAT5A/AvaI Gene Polymorphism in Four Italian Cattle Breeds

The STAT5A/AvaI polymorphism was investigated with PCR-RFLP in a sample of 339 cattle belonging to four breeds: Italian Friesian, Jersey, Italian Brown, and Podolica reared in south Italy. All three possible genotypes for the C/T polymorphism were identified. In these breeds, PCR-RFLP showed the predominance of the TT genotype in Italian Brown and Jersey cows; in Podolica and Italian Friesian CT is the most frequent genotype. The frequency of the T allele ranged from 0.55 to 0.81 in the analyzed populations. The distribution of genotypic and allelic frequencies at this locus was significantly different among the four populations based on a χ² test (P < 0.001), suggesting that the molecular characteristics of the STAT5A gene could be significantly affected by the breed selection. Gene heterozygosity, gene homozygosity, effective allele number, fixation index, and polymorphism information content (PIC) were calculated. The observed heterozygosity, as well as the N _e and PIC values, indicates high genetic variability in the Podolica breed. Podolica could be considered an interesting reservoir of genetic diversity for a species under high selective pressure elsewhere.     

Genetic Polymorphism of Microsatellite DNA in Two Populations of Northern Sheatfish (Silurus soldatovi)

In this article, population variations and genetic structures of two populations of northern sheatfish (Silurus soldatovi) were analyzed using 24 microsatellite loci enriched from southern catfish (S. meriaionalis Chen) by magnetic beads. Gene frequency (P), observed heterozygosity (Ho), expected heterozygosity (He), polymorphism information contents (PIC), and number of effective alleles (Ne) were determined. One population was wild, ripe individuals collected from Heilongjiang River (HNS); the other was cultured fry collected from Songhuajiang River (SNS). The Hardy-Weinberg equilibrium (HWE) was tested by the genetic departure index (d). The coefficient of gene differentiation G_ST and Φ_ST by AMOVA (Analysis of Molecular Variety) was imputed using Arlequin software in this study. In addition, a phylogenetic tree was constructed by UPGMA method based on the pairwise Nei's standard distances using PHYLIP. A total of 1 357 fragments with sizes ranging between 102 bp and 385 bp were acquired by PCR amplifications. The average number of alleles of the two populations was 8.875. Results indicated that these microsatellite loci were highly polymorphic and could be used as genetic markers. The mean values of the parameters P, Ho, He, PIC, and Ne were 0.165, 0.435, 0.758, 0.742, and 5.019 for HNS and 0.147, 0.299, 0.847, 0.764, and 5.944 for SNS, respectively. Although there were differences, there were no significant differentiations except for the locus HLJcf37. These populations to a certain extent deviated from HWE, such as excessive and deficient heterozygote numbers. The value of G_ST was 0.078 and above 98% of the variation were differences among individuals within the population, so the variation between populations was insignificant. Cluster analysis also showed that the relationships among individuals were very close. In conclusion, the microsatellite markers that were developed through this study are useful for genetic analysis and the genetic culture that was proposed in this study has no significant impact on S. soldatovi.     

Association of IL-17A and IL-17F single nucleotide polymorphisms with susceptibility to osteoarthritis in a Korean population

The damage incurred in osteoarthritis (OA) is mediated by a variety of cytokines, growth factors and inflammatory mediators. The importance of the interleukin-17 (IL-17) family in inflammatory and autoimmune disease is becoming increasingly apparent. Microsatellite association mapping reveals a primary osteoarthritis susceptibility locus on chromosome 6p12.3-q13. IL-17A and IL-17F genes that resided on chromosome 6p12.3-q13 are believed to play an important role in the primary OA susceptibility. We investigated the allele and genotype of IL-17A G-197A and IL-17F T7488C in 302 OA patients and 300 healthy subjects as controls. We employed a PCR-SSCP assay to identify the genotypes IL-17A G-197A and IL-17F T7488C. For IL-17A G-197A, there were significant differences in frequencies of genotype and allele of IL-17A G-197A between OA patients and controls (both p < 0.0001). For IL-17F T7488C, there were no significant differences in the allele frequency and genotype distribution for IL-17F T7488C between OA patients and controls (p = 0.938 and p = 0.1735, respectively). In conclusion, current study showed that polymorphism of IL-17A G-197A may be closely associated with susceptibility to the development of OA in the Korean population. However, there was no relationship between IL-17F T7488C polymorphism and OA susceptibility.     

Genetic diversity and variation in wild populations of dark sleeper (Odontobutis potamophila) in China inferred with microsatellite markers

Twenty-one highly variable microsatellite loci were used to investigate the genetic diversity and variation of Odontobutis potamophila in China. A total of 160 samples from five wild populations (Dangtu, Sheyang, Yuyao, Minjiang and Donxishan) were genotyped. All of the 21 microsatellite loci tested in this study showed polymorphism. The number of allele per locus ranged from 5.05 to 9.90. Locus 87a of Minjiang population had a 259-bp characteristic allele. The average observed heterozygosity and expected heterozygosity ranged from 0.33 to 0.62 and from 0.40 to 0.70, respectively. The pair-wise F_ST tests and NJ trees of the five O. potamophlia populations revealed that Dangtu, Sheyang, Yuyao and Dongxishan were genetically close to one another and distinct from Minjiang. Far genetic distances were observed among populations from distant geographical areas. This result provided guide for the use of O. potamophila breeds and the protection of the species.     

Genetic variation in populations of the threatened seagrass Halophila beccarii (Hydrocharitaceae)

Halophila beccarii (Hydrocharitaceae), a small monoecious seagrass, has been listed as a threatened species. In this study, a total of 106 samples were collected from four Chinese populations located at the northern limit of its distribution range. Using six polymorphic microsatellites, we found low genetic variation in this species, in which the mean number of alleles per locus was 2.8, and 16 multi-locus genotypes were revealed. In the four populations, the mean number of alleles per locus ranged from 1.2 to 2, one to eight genotypes were found, and clonal diversity ranged from 0 to 0.23; observed and expected heterozygosity ranged from 0.17 to 0.40 and from 0.09 to 0.24, respectively. Strong genetic differentiation was found among the populations, and the standardized fixation index (F′_ST) was 0.787. Species traits (i.e., clonal growth) and bottleneck effects due to drastic population fluctuation may contribute to the observed low genetic variation.     

Characterization of microsatellite markers derived from sequence databases for the European flounder (Platichthys flesus)

The European flounder (Platichthys flesus; Pleuronectidae) is an important commercial fish species. Nevertheless, no microsatellites for this species have been published to date. The sequence of flounder genes present in the public database was searched for short tandem repeats. Out of 12 microsatellite pairs derived from Sequenced Databases, five amplified successfully with an expected heterozygosity ranging from 0.43 to 0.75. The average allele number of these microsatellites was 4.8 per locus with a range between two and nine.     

Identification of unique alleles and assessment of genetic diversity of rabi sorghum accessions using simple sequence repeat markers

Genetic diversity among 42 sorghum accessions representing landraces (19), advanced breeding lines (16), local cultivars (2) and release varieties (5) with 30 simple sequence repeat (SSR) markers revealed 7.6 mean number of alleles per locus showing 93.3% polymorphism and an average polymorphism information content of 0.78 which range from 0.22 (Xtxp12) and 0.91(Xtxp321). The average heterozygosity and effective number of alleles per locus were 0.8 and 6.65 respectively. Cluster analysis based on microsatellite allelic diversity clearly demarcated the accessions into ten clusters. A total of 24 unique alleles were obtained from seven SSR loci in 23 accessions in a size range of 110–380 bp; these unique alleles may serve as diagnostic tools for particular region of the genome of respective genotypes. Selected SSR markers from different linkage groups provided an accurate way of determining genetic diversity at the molecular level.