西南矮马肌肉生长抑制素基因启动子区PCR-RFLP 多态性检测

利用PCR-RFLP技术对贵州矮马、德保矮马和宁强矮马3个品种的45个个体的肌肉生长抑制素(myostatin, MSTN)基因的启动子区进行多态性分析。结果表明,大小为204 bp的扩增片段经限制性内切酶SspⅠ酶切后,不同基因型经过测序发现156T→C突变,产生AA和AB两种基因型,没有发现BB基因型。贵州矮马和宁强矮马中AB基因型频率大于AA基因型,德保矮马中AA基因型占优势,在3种矮马品种A等位基因频率均大于B等位基因。卡方检测结果发现,贵州和德保矮马在该酶切位点处于平衡状态(P＞0.05),而宁强矮马在该位点分布差异显著(P＜0.05)。     

利用微卫星DNA对绵羊群体进行遗传平衡检测

利用4个绵羊微卫星基因座分析10个绵羊种群(3个引入品种、1个本地品种和6个杂种)的群体遗传平衡.Hardy-Weinberg平衡检验表明,绝大多数种群各基因座上的基因型偏离Hardy-Weinberg平衡;连锁不平衡检验表明,除个别种群的个别基因座外,同一条染色体上的3个微卫星(BP33、CSSM018和MCM148)处于连锁平衡状态;微卫星进化的三种模型(IAM、ISM和SMM)下,符号检验和Wilcoxon符号-秩检验均表明,各种群未经受显著的瓶颈效应影响,处于突变-漂移平衡.     

应用微卫星标记分析中国地方山羊瓶颈效应

为了评价中国山羊突变-漂移平衡状况,以及近期是否经历瓶颈效应,本研究采用联合国粮农组织(FAO)和国际动物遗传学会(ISAG)推荐的9对微卫星引物,检测了中国39个地方山羊品种和1个引进山羊品种的遗传多样性。并在双相突变模型(Two-phase model of mutation,TPM)下,利用Wilcoxon标记秩检验(Wilcoxon signed-rank test)分析杂合过度是否显著。结果显示济宁青山羊显著杂合过度,表明该山羊种群近期可能经历瓶颈效应,在遗传育种和资源保存中应加以考虑。     

德保矮马饲养管理技术及其在主产区保种推广应用效果

德保矮马是一种世界稀有的、中国微型马的代表品种,与英国的雪特兰矮马并称为世界两大矮马源流。由于多年来在德保矮马主产区,农户都是以传统方式进行饲养管理,条件差,技术落后不规范,对德保矮马的资源保护与发展极为不利。2006年主产区的德保矮马群体数量不足1 000匹,保种选育工作任重道远。笔者在近几年来结合实施《德保矮马种质资源保护技术研究项目》中,总结出德保矮马饲养管理技术并在主产区推广应用,取得良好效果。2011年末,主产区德保矮马群体规模达2 056匹,建立了德保矮马核心群,培育出后代成年体高75cm~80cm的德保矮马2匹,81cm~90cm的有26匹,群体质量得到进一步优化,为德保矮马种质资源保护、种群发展和地方旅游特色产业开发打下了坚实基础。本文对德保矮马的主要特性、饲养管理技术要点、推广主要措施和效果进行阐述。     

利用微卫星标记对宁强矮马和蒙古马遗传多样性的研究

通过8个微卫星位点的多态性检测对宁强矮马和蒙古马共83个个体进行了遗传多样性分析。计算各微卫星位点的等位基因频率、有效等位基因数(Ne)、多态信息含量(PIC)、杂合度(H)和F统计量。结果表明:8个微卫星座位中HMS2变异最大,HTG6变异最小;蒙古马的Ne、PIC、H的平均值均高于宁强马;总群体的平均遗传分化系数Fst为0.017(P<0.01),群体内近交系数Fis为0.171(P<0.01)。说明蒙古马和宁强矮马虽外形和性能上有很大差异,但在品种形成和进化上有着较近的遗传关系。     

宁强矮马

<正>1988年4月至6月间,我们在陕西省宁强县的广坪、阳平关两区的8个乡发现了体高在106cm以下矮马多匹,并命名为宁强矮马(NINGJIANG PONY),分布在嘉陵江以西北的秦岭南坡区,分布中心是巨亭、太阳岭、燕子砭、安乐河、八海等乡。该地区属暖温带山地湿润季风气候,海拔在1700m左右,地形地貌复杂,地势高低悬殊,气候复杂多变,立体水平阴阳坡向明显。这是继广西德保、四川安宁、贵州矮马之后,为我国马种资源开拓了又一新的源流,把我国矮马的分布区域向北推移了近千公里,具有很高的学术价值。 现就宁强矮马的初步考察情况报告如下: (一)宁强矮马的体质外貌特点 ①毛色与特征:宁强矮马以骝毛居多、其次是兔褐、黑色、栗色、白色,而以沙毛为少。宁强矮马鼻白、距白特征很少,侧面推测,该地区较为封闭。     

德保矮马X染色体选择信号筛选

旨在对德保矮马(Debao pony)X染色体的选择信号进行筛选。本研究利用Illumina公司开发的马芯片Equine 65KSNP BeadChip,对德保矮马、伊犁马、蒙古马进行X染色体扫描,获得2 339个SNPs位点。通过群体分化系数FST法和XP-EHH两种不同的方法,分别以伊犁马和蒙古马为对照群体对德保矮马进行X染色体选择信号检测。结果,筛选到两个受到较强选择区域4.0~39.9和87.1~123.5Mb,包含64个"离群位点"。通过基因注释筛选到PHEX、BCOR、PNPLA4和GPC3等与生长和骨骼发育相关的基因。研究结果发现,德保矮马的选育过程中X染色体很多与生长相关的基因受到了强烈的选择,其中部分在马中未见报道,可以作为研究矮小性状的重要候选基因。     

德保矮马资源保护与产业发展对策探讨

德保矮马是我国汉代(公元25-220年)史书中所称"果下马"的后裔,是我国最矮的著名地方马种资源之一,是中国矮马的代表,与英国设特兰矮马一起被成为世界上两大矮马源流。多年来,德保县作为国家级德保矮马资源保护区,在下大力气抓好德保矮马资源保护的同时,全力打造德保矮马特色品牌,推进德保矮马特色产业发展。笔者总结了多年来德保矮马资源保护与产业开发实践经验,主要分析德保矮马产业发展现状、存在的困难和问题及发展前景,并提出今后德保矮马产业发展的对策和建议。     

德保矮马种质资源现状及保种进展

<正>德保矮马属于中国西南马系百色马中的石山矮马,是漫长进化中自然形成的矮小马品种,身高为85～100厘米,体重200千克左右,是世界仅有的非人工矮化的自然形成的珍稀品种,2002已经被列入全国78个国家级畜禽重点保护品种之一。由于近年来德保矮马的役用功能逐渐被机械化取代,群体数量大幅减少,种质资源退化等严峻形势。因此,     

西藏阿里地区牦牛生态类群分子遗传多样性研究

利用多种分子标记鉴定西藏阿里牦牛生态类群遗传多样性状态,以期为阿里牦牛遗传资源的保护、开发和利用奠定理论基础。利用13个微卫星标记位点及线粒体D-Loop高变区分别对69头和50头西藏阿里牦牛进行了遗传多样性评估。结果显示,在13个微卫星位点中共检测出124个等位基因,其中TGL122和ILSTSO50位点的复等位基因数最多(15个),BGR3001位点的等位基因数最少(1个);从群体上来看,阿里牦牛群体的平均观测杂合度(Ho±SD)为0.579 0±0.013 9,其中11个位点偏离哈代-温伯格平衡,且近交系数(F_(IS))为0.192(P0.05);虽然依据IAM和TPM模型暗示该群体存在显著瓶颈效应(P0.05),但模式迁移图形仍为L-型分布;阿里牦牛线粒体D-loop区序列的794 bp片段范围内,共计鉴定到80个变异位点,同时构建得到38个单倍型,全部单倍型分为2个母系支系;群体平均单倍型多样性(Hd)为0.941,平均核苷酸多样性(Pi)为0.016 00。说明目前阿里牦牛群体内仍具有较丰富的母系遗传多样性,但群体整体可能存在近交和经历瓶颈效应的风险,故而需要进一步加强该群体保种工作,同时优化或改变现有保种模式和方案。     

Evaluation of genetic architecture and mutation drift equilibrium of Marathwada buffalo population in Central India

In the present study, microsatellite data on 24 loci were generated and utilized to evaluate the genetic architecture and mutation drift equilibrium of Marathwada buffaloes, a Central Indian population maintained under low input system. Sufficient allelic diversity was observed with a total of 109 alleles across different loci. The genetic diversity analysis of Marathwada buffaloes displayed moderate level of within breed variability in terms of mean number of alleles per locus (4.48) and heterozygosity values (Ho = 0.532, He = 0.624). The studied Indian buffalo population showed considerable heterozygote deficiency (F_IS = 0.138) and deviation from HWE at many investigated loci. Three quantitative tests viz. sign test, standardized difference test and Wilcoxon sign rank test and a qualitative test for mode shift distortion of allelic frequencies were employed to evaluate mutation drift equilibrium under three different models of microsatellite evolution. The population was found to deviate significantly under IAM and TPM, while it was reverse under SMM. The qualitative test for mode shift supported the results under SMM indicating the absence of genetic bottleneck in the recent past in Marathwada buffaloes.     

Detection of occurrence of a recent genetic bottleneck event in Indian hill cattle breed Bargur using microsatellite markers

The effective number of breedable individuals is a crucial determinant for maintaining genetic variability within a population. The population of Bargur, the hill cattle of South India, has gone down drastically by more than 93 % in the past three decades, and only a few thousand animals are available at present. The present study was undertaken to evaluate Bargur cattle for mutation drift equilibrium and to detect the occurrence of recent genetic bottleneck event, if any, in this population. About 50 unrelated animals, true to the type, were sampled and genotyped at 25 microsatellite loci. The mean observed heterozygosity (0.808?±?0.023) was higher than the mean expected heterozygosity (0.762?±?0.008) with 15 out of 25 microsatellite loci exhibiting heterozygosity excess when assumed under Hardy–Weinberg equilibrium. To evaluate Bargur cattle for mutation drift equilibrium, three tests were performed under three different mutation models, viz., infinite allele model (IAM), stepwise mutation model (SMM) and two-phase model (TPM). The observed gene diversity (H _e) and expected equilibrium gene diversity (H _eq) were estimated under different models of microsatellite evolution. All the 25 loci were found to exhibit gene diversity excess under IAM and TPM, while 22 loci were having gene diversity excess under SMM. All the three statistical tests, viz., sign test, standardized differences test, and Wilcoxon sign rank test, revealed significant (P?<?0.01) deviation of Bargur cattle population from mutation-drift equilibrium under all the three models of mutation. Furthermore, the qualitative test of allele frequency distribution in Bargur cattle population revealed a strong mode shift from the normal L-shaped form suggesting that the population had experienced genetic bottleneck in the recent past. The occurrence of genetic bottleneck might have led to the loss of several rare alleles in the population, which point towards the need for efforts to conserve this important cattle germplasm. The present study is the first report in demonstrating the genetic basis of demographic bottleneck in an Indian cattle population.     

Evaluation of genetic variability and mutation drift equilibrium of Banni buffalo using multi locus microsatellite markers

The present study was conducted to evaluate genetic diversity of Banni buffalo and its relationship/differentiation with Murrah using genotypic data on 24 heterologus bovine specific microsatellite marker loci. A total of 138 alleles were observed with a mean of 5.75 alleles/locus across two populations. The mean observed and expected heterozygosities were found to be 0.441 and 0.572 respectively in Banni buffaloes while it was 0.464 and 0.610 respectively in Murrah buffaloes. The average heterozygosity deficit was significantly positive with substantially higher values observed in Banni (22.3%) and Murrah (24%) buffalo populations. Banni buffalo population, when evaluated for mutation drift equilibrium revealed significant heterozygosity excess under IAM while no such excess was observed under SMM and TPM. The qualitative graphical test revealed a normal L-shaped distribution of allele frequencies indicating the absence of genetic bottleneck in Banni buffaloes. The mean estimates of F-statistics over all the loci were 0.376 for F_IT, 0.187 for F_ST and 0.232 for F_IS respectively. Analysis of molecular variance (AMOVA) revealed 18.95% of the total variation being explained by between breed differences while 14.36% of the variation explained differences between individuals within each breed. Genotype assignment test revealed distinct clustering of Banni and Murrah buffaloes. Genetic distance was estimated using three different methods, the results of which revealed considerable genetic differentiation between these two buffalo populations. The divergence time between Banni and Murrah buffaloes was estimated to be around 7286 years. The results of the present study may be helpful in decision making for conservation programs as Banni buffalo population is on decline.     

Novel Variants in the HMGA2 Gene Are Associated With Withers Height in Debao Pony

The Debao pony is a well-known dwarf horse breed in China. High-mobility group AT-hook 2 (HMGA2) gene is regarded as one of the important candidate genes regulating body height in horses. The aim of this study was to study the association between mutations in HMGA2 gene and withers height in Debao ponies. The polymorphisms in all exons and partial introns of the HMGA2 gene were screened with sequencing across 180 Debao ponies. And the association between the DNA variants and withers height was analyzed. Seven genetic variants were identified in HMGA2 gene, including six novel variants. Among them, six mutations were located in two closed linked blocks. The three novel variants (In1-1, E5-1, and E5-2) in the 1st intron and the fifth exon and a known mutation (In1-2) had significant association with withers height in Debao ponies. These results suggest that the four variants have the potential to be used as genetic markers for dwarf horse breeding activities.     

中国矮马与普氏野马的亲缘关系

产于中国西南山地的矮马是一种珍贵的资源,它的优良品质可以与原产于设得兰群岛的欧洲矮马媲美。本文研究了产自广西德保的中国矮马骨骼标本,通过与欧洲矮马的对比,发现它们之间的头骨、颊齿和肢骨上都 存在较大的差异,显然亲缘关系较远。而中国矮马与普氏野马的头骨的比例上却相当一致,头骨在马属的系统演化中具有非常重要的意义,因此,这一结果证明中国矮马与普氏野马有密切的亲缘关系。尽管从汉代起中国已广泛引入西方马种     

玉树马和德保矮马SLC36A1基因多态性研究

 控制马香槟毛色的CH（Champagne gene）基因家族包含4个候选基因（SLC36A1、SLC36A2、SLC36A3、SPARC）,研究发现SLC36A1基因外显子2的突变是造成马香槟毛色的关键位点。为揭示中国马SLC36A1基因遗传多态性,本研究以玉树马和德保矮马共74个样本为研究对象,以马DNA池为模板扩增SLC36A1基因的10个外显子及部分内含子序列并进行测序分析。共发现马SLC36A1基因5个SNPs,分别位于内含子3（g.26699953 A>G, g.26699851 G>C, g.26699850 G>C）,外显子4（g.26699562 G>A）及外显子6（g.26697018 C>T）。利用PCR RFLP方法对74个家马样本进行基因分型,发现外显子6的SNP有基因型CC、CT;外显子4的SNP有基因型GG、GA;内含子3的g.26699850 G>C突变有基因型GG、GC;内含子3的另外2个SNPs（g.26699953 A>G, g.26699851 G>C）通过测序,发现有AA、AG、GG与GG、GC、CC基因型。所有5个马SNPs均为野生型占主要优势。由此界定了马SLC36A1基因有9种单倍型（H1 H9）,其中H5是最主要的单倍型。德保矮马遗传多样度为0.4190,比玉树马（0.2228）高,表明德保矮马香槟毛色遗传多态性比玉树马更丰富。玉树马与德保矮马的平均单倍型多样度为0.3160,表明其香槟毛色遗传多态性相对较低。     

马生长激素基因多态性与体尺指标之间的关联性分析

为研究广西德保矮马、百色马和新疆伊犁马的生长激素(GH)基因多态性与体尺指标之间的相关性,本实验利用PCR-SSCP技术分析3个品种277匹马GH基因5′侧翼区、第3外显子、第4外显子、第5外显子的遗传多态性。结果表明:只有GH基因第5外显子出现多态性,表现为AA、BB和AB 3种基因型,其他片段未发现多态性。群体遗传学分析表明,等位基因A和B的基因频率相等;Hardy-Weinberg平衡检验显示,3个品种马均处于非平衡状态;它们的多态信息含量均为中度多态。统计分析表明,GH基因第5外显子的基因型与3个品种马体尺指标之间无显著相关性。     

德保矮马与哈萨克马 KIT 基因多态性分析

 马毛色是品种鉴定和个体识别的重要依据。马 KIT 基因位于3号染色体,KIT 基因突变影响马毛色及毛色的分布。对德保矮马和哈萨克马69个个体的 KIT 基因21个外显子及部分内含子直接测序,共发现了5个SNPs,其中1个位于5'-UTR区（g.91214T>G）,1个位于内含子20 （g.171356C>G）,另外3个分别位于外显子15、20和21(g.164297C>T;g.170189C>T;g.171471G>A,p.Ala960Thr)。用PCR-RFLP方法对69个个体进行分型,发现外显子15有3种基因型TT、CT、CC;外显子20有3种基因型TT、CT、CC;外显子21有2种基因型GG与GA,且均为野生型占优势。德保矮马 KIT 基因多态性比哈萨克马更丰富。