共查询到18条相似文献，搜索用时 46 毫秒
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绵羊血液蛋白多态性是其生化多态的表现形式之一，实质上是绵羊种群适应多种生态环境的结果，研究家畜血液蛋白多态性在分析种群遗传结构，探讨品种起源与分化，合理利用杂交组合以及进行新品种培育等方面，成为近年来遗传资源多样性和遗传标记研究的热点之一。甘肃高山细毛羊是在海拨2600米以上的高原草原育成的我国第一个高山型细毛羊新品种，但由于个体净毛鼍低，羊毛品质不理想，使得细毛羊澳化成为改良甘肃高山细毛羊的必由途径。 相似文献
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我国养羊历史悠久，羊品种资源丰富。根据绵羊形式、特性以及分布，有记载的绵羊品种共有30个，地方绵羊品种15个，培育品种7个，引入品种8个，还有一些没有记入的品种。以上的绵羊品种，一般都具有适应性好、耐粗易抓膘、抗病抗逆等优点，而且，它们生产性能优良、产品丰富多样。因此，分析这些绵羊品种的遗传资源多样性，以及验证品种之间的亲缘关系，可更好地保存并利用这些优良品种。 相似文献
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为研究中亚与南亚地区绵羊Cat过氧化氢酶的遗传多样性，采用单向水平板淀粉凝胶电泳检测方法对湖羊、同羊、滩羊、洼地绵羊、小尾寒羊和巴音布鲁克绵羊的Cat座位进行了检测，并引用分布于我国周边国家和地区的10个绵羊品种作为分析背景，计算其平均杂合度以及对其中立性测验的结果进行分析。结果显示：①16个绵羊群体的Cat座位基因分化系数Gst=0．2807，说明有71．93％的变异是由群体内的遗传多态现象引起的，只有28．07％的变异来自于群体间的差异；②中立性检测的观察值均在L95和U95之间，表明Cat位点为中立性位点，其遗传多样性基本上未受选择等因素的影响。 相似文献
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藏系绵羊染色体的显带研究 总被引：7，自引：1，他引：6
藏系绵羊是我国绵羊三大系统之一,主要分布于我国西南的青藏高原、甘肃及四川西北(甘孜州、阿坝州等地的高海拔地区。对家绵羊Ovis aries)染色体研究,国外已有多篇报道,国内沈长江等作了滩羊、蒙古羊及湖羊染色体研究工作。藏系绵羊染色体显带研究尚未见公开报道。本文对藏系绵羊染色体进行比较全面的显带研究,不仅可为家畜品种遗传资源调查积累资料,而且为绵羊优良品种的选育提供细胞遗传学方面的证据,此外,对于研究绵羊的起源与进化关系等也有重要意义。 相似文献
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我国青藏高原拥有世界牦牛最大存栏量,且牦牛养殖业是我国高原牧区最重要的畜牧支柱产业。我国地方牦牛品种资源丰富,其不仅具有优异的高原适应性优势,而且在鲜肉品质、乳制品、毛皮品质等方面的经济性能优势突出。然而,由于高原地区自然条件恶劣、科技水平及饲养管理水平落后等多种因素,致使当前我国固有牦牛资源品种遗传改良进程缓慢、生产力低下。本文全面综述了我国当前牦牛种质资源保护概况、主要牦牛品种生产性能特征、牦牛群体遗传多样性与种群系统发育关系研究成果以及牦牛重要经济及适应性性状相关候选基因与遗传标记筛选的研究进展。这可为我国牦牛遗传资源保护与利用、牦牛新品种(系)的培育以及我国牦牛产业良性发展提供参考。 相似文献
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我国主要地方绵羊品种遗传亲缘关系 总被引：12，自引：0，他引：12
利用 10种 10碱基的随机引物 ,分析了我国 8个地方绵羊品种计 88只绵羊的随机扩增多态 DNA。结果表明 ,我国地方绵羊品种基因组 DNA多态位点百分率为 81.36 % ,群体平均遗传多样性指数为 1.3370 ,具有丰富的群体遗传多样性。但滩羊、小尾寒羊、藏绵羊和蒙古羊群体遗传多样性程度较低 ,应加强保种措施。群体遗传分化指数为0 .9172 ,说明遗传变异主要存在于群体间。品种间的分子聚类关系基本上反映了品种间的遗传亲缘关系 ,与品种的形成历史及我国地方绵羊的起源进化学说基本一致 ,具有相同来源的蒙古羊、乌珠穆沁羊、小尾寒羊和湖羊的分子聚类关系表明 ,4个地方绵羊品种间已经有了明显的遗传分化 ,小尾寒羊、乌珠穆沁羊间遗传分化较低 ,湖羊与蒙古羊之间相对较高 ,而小尾寒羊和乌珠穆沁羊与湖羊和蒙古羊之间的遗传分化最高 相似文献
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4个绵羊品种MHC-DRB3基因外显子2的多态性分析 总被引：1，自引：1，他引：1
采用PCR-RFLP方法分析4个绵羊品种（阿勒泰羊、中国美利奴肉用多胎品系、湖羊和陶塞特羊）MHC-DRB3基因第2外显子的多态性，并进行聚类分析以及基因杂合度和多态信息含量的计算。结果表明：在绵羊MHC-DRB3基因第2外显子第122、154、168、220和241 bp碱基处表现出多态性；χ2适合性检验结果表明，4个绵羊群体MHC-DRB3基因的第2外显子的PstⅠ酶切位点达到了Hardy-Weinberg平衡状态，TaqⅠ和HaeⅢ酶切位点多态性均未达到Hardy-Weinberg平衡状态；4个绵羊群体基因杂合度和多态信息含量值分别在0.693～0.774和0.662～0.738之间，表明4个绵羊品种具有丰富的遗传多样性；聚类结果表明，中国美利奴肉用多胎羊和湖羊亲缘关系最近，阿勒泰羊和陶塞特羊关系较远，与实际选育过程一致，MHC-DRB3多态性可作为绵羊育种标记进一步研究。 相似文献
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Maryam Nosrati Hojjat Asadollahpour Nanaei Zeinab Amiri Ghanatsaman Ali Esmailizadeh 《Reproduction in domestic animals》2019,54(2):358-364
Ovulation rate and prolificacy are the most important reproductive traits that have major impact on the efficiency of lamb meat production. Here, we compared the whole genomes of the Romanov sheep, known as one of the high prolific breeds, and four other sheep breeds namely Assaf, Awassi, Cambridge and British du cher, to identify genetic mechanisms underlying prolificacy in sheep. Selection signature analysis revealed 637 and 477 protein‐coding genes under positive selection from FST and nucleotide diversity (Pi) statistics, respectively. Further analysis showed that several candidate genes including LEPR, PDGFRL and KLF5 genes are involved in sheep prolificacy. The identified candidate genes in the selected regions are novel and provide new insights into the genetic mechanisms underlying prolificacy in sheep and can be useful in sheep breeding programmes to develop improved breeds for high reproductive efficiency. 相似文献
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自然界中鸟类呈现出丰富的羽毛颜色,羽色性状在躲避天敌、捕食、求偶及抵御紫外线等方面都具有重要作用。对鸡羽毛颜色性状的研究有助于加强品种区分、识别,在育种工作中建立品种间的显著标识和保障同一品种外观整齐尤为重要。羽毛颜色是禽类表型遗传研究的重要组成部分,它主要由黑色素和类胡萝卜素所决定。目前鸡羽毛颜色性状遗传调控机制的研究大多集中在黑色素相关通路,其中,Wnt、KIT/KITL和EDN3/EDNRB等信号通路对黑素细胞的生长发育、迁移和分化具有重要的调控作用,α-MSH/ASIP-MC1R信号通路负责调控黑色素的合成。已有研究显示,通过全基因组范围内的遗传变异检测技术挖掘与羽色性状相关的基因和变异位点,可以揭示黑羽、麻羽、显性白羽、隐形白羽、常染色体白化、银羽、性连锁不完全白化、深棕色羽、淡紫色羽(灰羽)、非依赖酪氨酸酶的隐性白羽、斑点羽和性连锁横斑羽(芦花羽)等多种羽色性状的遗传调控机制。此外,以图灵模型为理论基础可以解释复杂羽色图案的形成机制。作者通过总结黑色素相关调控通路与图灵模型对家鸡羽毛颜色性状的遗传调控机制,对近年来已经确定基因座的家鸡羽毛颜色性状相关研究展开综述,以期为鸡羽色分子机制研究以及在育种过程中开展鸡羽色性状标记辅助选择提供参考。 相似文献
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M. Ćurković J. Ramljak S. Ivanković B. Mioč A. Ivanković V. Pavić M. Brka C. Veit‐Kensch I. Medugorac 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2016,133(1):71-80
The phylogenetic layout of the genotyped (30 microsatellite) 18 sheep breeds in this study demands and provides the opportunity to evaluate both neutral and adaptive components of genetic diversity in a naturally and artificially selected and subdivided sheep population. Seven Pramenka strains from Bosnia and Herzegovina and Croatia characterized by a very low intensity of artificial selection, preserved the highest neutral genetic variability. Eight central and north‐western European breeds under considerable artificial isolation and selection preserved the lowest genetic variability. Only combinations of various phylogenetic parameters offer a reasonable explanation for underlying evolutionary forces working in the investigated island and mainland sheep breeds under variable natural and artificial selection. More than 60% of total genetic, diversity was allocated to virtually unselected Pramenka strains, and an additional 25% to native moderately selected Graue Gehoernte Heidschnucke and intensively selected Ostfriesische Milchschafe. Some economically very important breeds and strains did not contribute to a pool with maximal genetic diversity, while they play an important role in the cultural heritage of respective countries. 相似文献
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A.L. Pons V. Landi A. Martinez J.V. Delgado 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2015,132(3):268-276
The Balearic sheep breeds, Mallorquina, Menorquina, Roja Mallorquina, Ibicenca and one possible new genetic group, Formentera, constitute a unique genetic resource in the Mediterranean farming landscape, displaying high genetic diversity levels and being well differentiated among themselves and with respect to the continental sheep breeds. We used a microsatellite panel of markers to study genetic diversity and relationships with other Spanish breeds. The results reported in this study have important implications for the use, conservation and breeding of Balearic sheep stocks. A mean number of 7.59 alleles was found among the Balearic sheep breeds for the microsatellites scored. The whole mean value of observed heterozygosity amounted to 0.62, whereas the expected heterozygosity value was 0.69, suggesting the presence of a great degree of genetic variability, although a significant deficit of heterozygotes was detected for some markers. Genetic distance estimates showed that Balearic sheep are differentiated from the other Spanish breeds and in particular, from the Merino type. The Ibicenca breed showed the highest distance value from other breeds. The neighbour‐net method of analysis clustered the Roja Mallorquina, Menorquina and Mallorquina breeds. The Structure results clearly demonstrated the genetic differentiation among the four Balearic sheep breeds, with the Ibicenca and Formentera races joined, with slight migration among them. Few external genetic influences from the Spanish mainland breeds were detected. 相似文献
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Wade CM 《Veterinary journal (London, England : 1997)》2011,189(2):183-188
This review assesses evidence from DNA analysis to determine whether there is sufficient genetic diversity within breeds to ensure that populations are sustainable in the absence of cross breeding and to determine whether genetic diversity is declining. On average, dog breeds currently retain approximately 87% of the available domestic canine genetic diversity. Requirements that breeding stock must be 'clear' for all genetic disorders may firstly place undue genetic pressure on animals tested as being 'clear' of known genetic disorders, secondly may contribute to loss of diversity and thirdly may result in the dissemination of new recessive disorders for which no genetic tests are available. Global exchange of genetic material may hasten the loss of alleles and this practice should be discussed in relation to the current effective population size of a breed and its expected future popularity. Genomic data do not always support the results from pedigree analysis and possible reasons for this are discussed. 相似文献
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Blackburn HD Paiva SR Wildeus S Getz W Waldron D Stobart R Bixby D Purdy PH Welsh C Spiller S Brown M 《Journal of animal science》2011,89(8):2336-2348
Understanding existing levels of genetic diversity of sheep breeds facilitates in situ and ex situ conservation activities. A comprehensive evaluation of US sheep breeds has not been previously performed; therefore, we evaluated the genetic diversity among and within 28 US sheep breeds. Both major and minor breeds were included in the analysis and consisted of 666 animals from 222 producers located in 38 states. The level of within-breed genetic diversity was variable and not dependent upon status of a breed as a major or minor breed. Bayesian cluster analysis indicated the breeds were grouped more by physiological differences (meat vs. wool production) rather than geographic origin. Results suggest several actionable items to improve in situ and ex situ conservation. The results clearly identify breeds in need of increased in situ and ex situ management (e.g., Hog Island and Karakul) and allow several suggestions for in situ management of flocks. Conversely, several of the breeds appear genetically similar and therefore require less emphasis on collecting germplasm samples for the gene bank. Commercially important breeds (e.g., Rambouillet and Suffolk) were found to have substantial variation, which should enable breeders to proceed, unencumbered by genetic diversity concerns, with selection strategies that maximize profit. 相似文献
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试验旨在研究地方绵羊品种的遗传变异,为种质资源评价、保护和利用提供理论数据。利用5个微卫星标记分析4个地方绵羊品种的遗传多样性,根据等位基因组成及频率进行群体遗传统计分析;基于品种间标准遗传距离(Ds)和Nei氏遗传距离,分别构建UPGMA系统发生树。4个地方绵羊品种共检测到70个等位基因,各位点等位基因数(Na)在10~18之间;4个地方绵羊品种平均有效等位基因数(Ne)为3.81~5.68个,平均多态信息含量(PIC)为0.6152~0.7373,平均遗传杂合度(H)为0.6711~0.7820;4个地方绵羊品种间遗传分化系数为0.0847,标准遗传距离(Ds)和Nei氏遗传距离晋中绵羊与乌珠穆沁羊为最大(0.5775、0.6126),小尾寒羊与乌珠穆沁羊为最小(0.1542、0.1955),首先小尾寒羊与乌珠穆沁羊聚为一类,晋中绵羊与广灵大尾羊聚为另一类,然后两类聚在一起形成一大类。结果表明,4个地方绵羊品种遗传变异大、多样性丰富;品种间遗传分化小,但小尾寒羊和乌珠穆沁羊与晋中绵羊和广灵大尾羊间已有明显分化。选择的5个微卫星座位均为高度多态位点,可作为有效遗传标记用于绵羊品种遗传多样性和系统发生关系分析。各地方绵羊品种分子聚类关系与其形成史、分化及地理分布基本一致。 相似文献