中国牛亚科家畜遗传多样性研究及其保护

中国是世界上牛品种资源最丰富的国家之一,但同时也面临着严重威胁.本文从遗传多样性的重要性、中国牛亚科家畜遗传多样性面临的严重威胁、遗传多样性研究进展及其保护现状等方面进行了综述.     

中国地方品种牛血液同工酶遗传多样性研究进展

本文综述了中国地方黄牛和水牛品种的血液同工酶遗传多样性的研究现状及其在牛遗传育种中的应用。     

牛遗传资源评价与利用研究进展

为了提高我国牛资源品种的保护以及遗传多样性的利用,文章对我国的牛遗传资源现状进行了概述,并对我国牛遗传资源在不同水平方面的研究进展进行了综述,提出了保护、开发利用我国牛遗传资源的建议。     

牛遗传资源分子遗传多样性的研究进展

作者对牛遗传多样性的主要研究方法（主要包括线粒体DNA、微卫星DNA多态性、单核苷酸多态性、高通量SNP检测方法及全基因组选择方法）及其在牛分子遗传多样性研究方面的应用进行了介绍。     

沼泽型水牛微卫星DNA的遗传多样性分析

为探究中国沼泽型水牛品种或类群的遗传多样性,本研究采用了沼泽型水牛30个微卫星标记结合LabChip芯片检测法对德昌水牛、德宏水牛、温州水牛、贵州水牛、西林水牛、富钟水牛及两个引进品种摩拉水牛、尼里－拉菲水牛等40个样本进行了检测和遗传多样性分析。结果表明,在30个微卫星DNA标记上共发现332个等位基因,平均基因多样性和PIC值分别为0.7808和0.7554。聚类分析结果显示,德宏水牛和德昌水牛先聚为一类,随后与富钟水牛、贵州水牛、温州水牛、西林水牛聚为一类;摩拉水牛与尼里－拉菲水牛聚为一类。本研究证实了所选的30个沼泽型水牛微卫星DNA标记可作为有效的遗传标记用于水牛品种间的遗传多样性分析,同时也丰富了当前的水牛微卫星标记资源。     

昭通牛种质资源保护技术措施

遗传资源保护是关系到养殖业持续发展和生物多样性的重大问题。昭通牛主产于云南省昭通市,是昭通人民经过长期的选育加上自然因素影响而形成的役肉兼用型本地品种。该品种被收入《云南省家畜家禽品种志》(1987)、《中国畜禽遗传资源志·牛志》(2011)、《云南省畜禽遗传资源志》(2015),时至今日仍是昭通市的当家品种。通过对昭通牛的选种选配,充分发掘昭通牛的优良性状和生产性能,能有效保护昭通牛这一频临灭绝的生物资源,保存未来不可预见利用价值的昭通牛所有基因,对昭通市牛养殖业可持续发展具有重要作用,对维护生物多样性具有重要意义。     

黄陂牛mtDNA D-loop区遗传多样性研究

【目的】探究黄陂牛的遗传多样性与母系起源。【方法】采用PCR扩增、测序及生物信息学方法。【结果】在21头黄陂牛mtDNA D-loop区共检测到55个变异位点,定义了10个mtDNA单倍型,平均单倍型多样度为0.7760,平均核苷酸多样度为0.0234,表明黄陂牛具有丰富的遗传多样性。构建的NJ系统发育树表明黄陂牛具有瘤牛和普通牛两个母系起源。【结论】黄陂牛有丰富的遗传多样性,有瘤牛和普通牛两个母系起源,且受瘤牛的影响较大。     

云岭牛基因组研究进展

为了研究云岭牛基因组研究进展情况,本文综述了云岭牛遗传多样性研究、云岭牛基因与其性状、环境适应性、肉质及性情研究进展情况,并对云岭牛基因组研究进行总结和展望,以期为云岭牛基因组研究及云岭牛培育、遗传改良提供参考。     

中国水牛mtDNA D-loop区遗传多样性与母系起源

[目的]检测中国水牛21个群体232条线粒体DNA D-loop 915 bp全序列的遗传多样性及系统进化关系.[方法]PCR扩增、测序和生物信息学方法.[结果]发现232条序列中共有87种单倍型,其核苷酸多态位点88个,其中有79个转换,6个颠换,3个颠换与转换共存.中国水牛mtDNA D-loop区核苷酸多样度(π值) 为0.01403±0.00178, 单倍型多样度(H)为0.8460±0.0240,表明中国水牛mtDNA 遗传多样性丰富.根据单倍型构建了中国水牛的NJ分子系统树,发现中国水牛变异类型主要为两个大支系A和B,表明中国水牛有两个主要母系起源.进一步分析发现支系B具有较大的差异,可以细分为两个亚支B1 和B2.[结论]中国水牛mtDNA 遗传多样性丰富,有2个母系起源.     

西藏牛和日喀则驼峰牛Y-SNPs遗传多样性及父系起源研究

[目的]分析西藏牛和日喀则驼峰牛的Y染色体遗传多样性及父系起源。[方法]采用PCR扩增、测序及生物信息学方法。[结果]通过对13头西藏牛Y-SNPs分析,发现西藏牛包含普通牛Y1、Y2及瘤牛Y3三种单倍型组,其频率分别为0.077、0.846和0.077;对8头日喀则驼峰牛Y-SNPs的分析表明,日喀则驼峰牛具有普通牛Y2和瘤牛Y3两种单倍型组,其频率分别为0.125和0.875。西藏牛和日喀则驼峰牛的单倍型多样度分别为0.2949±0.1558和0.2500±0.1802,表明西藏牛和日喀则驼峰牛具有较低的父系遗传多样性。[结论]西藏牛主要为普通牛Y2起源,日喀则驼峰牛主要为瘤牛Y3起源,且其遗传多样性较低。     

北京郊区畜禽品种生物多样性状况的分析

畜禽品种资源的多样性是多样性的重要组成部分,其多样性的保护直接关系到畜牧业可持续发展,攸关到人类社会的政治经济生活。本研究重点调查了北京市地方畜禽品种的状况,并按照群体近交系数的大小以及相应有效群体大小的方法分析评价了畜禽品种资源的受胁程度,研究发现北京市目前的6个地方品种资源中,除了北京鸭、本地小尾绵羊和本地山羊以外,其余的三个畜禽品种资源北京油鸡、本地黄牛和本地兔都受到了不同程度的威胁。其中本地黄牛和本地兔所受到威胁最为严重,为“严重威胁”的等级,北京油鸡处在“最低威胁程度等级”。     

Developing a typology for local cattle breed farmers in Europe

Recognizing cultural diversity among local breed farmers is crucial for the successful development and implementation of farm animal genetic resources FAnGr conservation policies and programmes. In this study based on survey data collected in the EUropean REgional CAttle breeds project from six European countries, a typology of local breed farmers was designed and profiles for each of the farmer types were developed to assist these policy needs. Three main farmer types were constructed: production‐oriented, product and service‐oriented and hobby‐oriented farmers. In addition, seven subtypes were characterized under the main types: sustainable producers, opportunists, multi‐users, brand makers, traditionalists, pragmatists and newcomers. These types have many similarities to the ‘productivist’, ‘multifunctional’ and ‘post‐productivist’ farmer types. The typology not only reveals the high level of diversity among local cattle breed farmers in Europe, which presents an opportunity for the in situ conservation of animal genetic resources, but also a challenge for policy to meet the differing requirements of the farmer types.     

地方、培育、引入品种资源的保存与发展的研究进展

作者就20世纪 80年代以来我国多次畜禽资源调查的结果作了详细的介绍,报道了576个品种在近30年来的变迁情况。除了常见的马、驴、黄牛、水牛、大额牛、牦牛、绵羊、山羊、猪、鸡、鸭、鹅、特禽的品种以外,尚有7种,如骆驼、兔、梅花鹿、马鹿、水貂、貉、蜂等动物。其中地方品种426个,培育品种73个,引入品种77个。已有19个地方品种灭绝,37个受严重威胁。作者回顾了20世纪末开始应用遗传检测手段,包括个体、细胞、蛋白质和分子水平4个层次的研究进展。证明多层次综合研究才能反映品种的全貌。建议资源调查中要着重选育强度带来的影响,品种调查提纲必须周密,要以品种特征和外貌为主,与遗传分析相结合,才可能提出可行的保种和开发方案。作者论证了配子和胚胎超低温保存、DNA保存的前景,并指出与企业合作进行保种的动向,国家应长期重点加以支持。     

Analyses of Genetic Diversity and Phylogeny of mtDNA D-loop from Yak in Karakoram-Pamir Area

This experiment was conducted to clarify the genetic diversity,genetic differentiation and phylogenetic status of yak in Karakoram-Pamir area.The mtDNA D-loop region sequence was selected as a molecular marker,and the sequence and genetic diversity of the mtDNA D-loop region of yak in Karakoram-Pamir area were analyzed by PCR direct sequencing and bioinformatics methods.The yak sequence in GenBank was used.The maximum likelihood method was used to construct the phylogenetic tree and the intermediary network relationship.The results showed that the mtDNA D-loop sequence of yak in Karakoram-Pamir area was rich in A and T bases,with AT content of 61.2%,and there were 63 polymorphic loci,accounting for 7.04% of the total number of nucleotides.The results indicated that A and T bases were rich in the mtDNA D-loop sequences at 61.2%.There were 63 mutation sites,accounting for 7.04% of all nucleotides,The average haplotype diversity (Hd) was 0.806,the average nucleotide diversity (π) was 0.01528,and the average nucleotide difference (K) was 13.509,indicating that the yak was rich in genetic diversity in Karakoram-Pamir area;Through phylogenetic analysis,there were two branches in yak in China,forming two branches and six small clades.The yak in Karakoram-Pamir area involved in this study had two different maternal origins.Additionally,yak in the Karakoram-Pamir area was less shared with other breeds of yak haplotypes.In the branch C,the yak group in the Karakoram-Pamir area accounts for a large proportion and was shared with wild yak.The yak population in Karakoram-Pamir area had a unique genetic background,which might be the result of early domestication of wild yaks.It was suggested to increase the identification of yak breeds and the formulation of breed standards in this area,and strengthen the protection of yak genetic resources in this area.According to the current situation of the population,wild blood yaks were introduced for purification and rejuvenation to prevent breed degeneration and decrease of genetic diversity.The introduction of foreign yak breeds and disorderly hybridization were reduced to ensure the characteristics of this breed of high-quality yak breed resources.     

Research opportunities in the field of animal genetic resources

Animal genetic resources are those animal species that are used, or may be used, for the production of food and agriculture, and the populations within each of them. The working unit of a database for farm animal genetic resources is the breed, a term taken in its widest possible sense to mean a population within the species, possessing a number of particular traits that permit the grouping of these animals under a common label and are associated to geographical areas and human groups. Research opportunities cover a wide range of thematic areas. The biggest gap in knowledge is animal breeding for local populations in harsh environments. There is also a lack of research in functional genetics and genomics of adaptation and disease resistance traits. By comparison, breed characterization, in particular molecular characterization, has been a more popular research subject. The same can be said for conservation, although some fundamental questions on genetic diversity and risk of its loss are still unanswered. Research is required to understand the socio-economic, infrastructural, technical and formal constraints that limit the operation of sustainable conservation programs in less developed countries. Information systems on animal genetic resources need input from research and data capture networks, in order to achieve a reasonable degree of completeness. Economic analysis and issues related to gene flow and access and benefit sharing should also profit from more research.     

Genetic diversity of Swiss sheep breeds in the focus of conservation research

There is constant pressure to improve evaluation of animal genetic resources in order to prevent their erosion. Maintaining the integrity of livestock species as well as their genetic diversity is of paramount interest for long-term agricultural policies. One major use of DNA techniques in conservation is to reveal genetic diversity within and between populations. Forty-one microsatellites were analysed to assess genetic diversity in nine Swiss sheep breeds and to measure the loss of the overall diversity when one breed would become extinct. The expected heterozygosities varied from 0.65 to 0.74 and 10.8% of the total genetic diversity can be explained by the variation among breeds. Based on the proportion of shared alleles, each of the nine breeds were clearly defined in their own cluster in the neighbour-joining tree describing the relationships among the breeds. Bayesian clustering methods assign individuals to groups based on their genetic similarity and infer the number of populations. In STRUCTURE, this approach pooled the Valais Blacknose and the Valais Red. With BAPS method the two Valais sheep breeds could be separated. Caballero & Toro approach (2002) was used to calculate the loss or gain of genetic diversity when each of the breeds would be removed from the set. The changes in diversity based on between-breed variation ranged from −12.2% (Valais Blacknose) to 0% (Swiss Black Brown Mountain and Mirror Sheep); based on within-breed diversity the removal of a breed could also produce an increase in diversity (−0.6% to + 0.6%). Allelic richness ranged from 4.9 (Valais Red) to 6.7 (Brown Headed Meat sheep and Red Engadine Sheep). Breed conservation decisions cannot be limited to genetic diversity alone. In Switzerland, conservation goals are embedded in the desire to carry the cultural legacy over to future generations.     

中国马遗传资源保护与利用研究

中国马种资源丰富,养马历史悠久。马曾在人类社会早期的生产生活中发挥过重要作用。作者简要综述了中国马种的起源,地方马品种的种类、分布,中国马遗传多样性研究现状及马业的发展。     

中国山羊品种资源及其遗传多样性研究

本文论述了中国山羊的起源、品种遗传资源及其遗传多样性的研究进展。最新调查 显示中国的山羊品种达50个,其中43个为地方品种,4个培育品种,3个引入品种,许多品种 具有独特的生产性能或适应能力。大量研究表明,我国山羊遗传多样性较为丰富。     

Population genetic analysis of the Brahman cattle (Bos indicus) in Colombia with microsatellite markers

Summary The Brahman is one of the most popular breeds for meat production in the Neotropics. However, genetic studies of the breed in Latin American countries have only recently begun. In total, 178 animals of the Brahman breed from 20 Colombian provinces were genotyped at 11 microsatellite markers with the aim of studying the genetic diversity of this population and its genetic relationships with zebuine and taurine breeds. The outcomes of multivariate analyses, Bayesian inferences and inter‐individual genetic distances suggested that there is no genetic sub‐structure in the population, because of the high rate of animal migration among provinces. The population shows a high degree of heterozygosity and allelic diversity compared with other breeds, reflecting its multibreed origin. The study of the genetic relationships among the breeds reveals that the Brahman breed belongs to the zebuine group. However, it is the population nearest to taurine breeds with high frequencies of taurine alleles. Intensive artificial selection may have favoured the taurine alleles after the breed was formed. There has also been some degree of mixture with local taurine breeds while the Brahman breed has evolved in Colombia.     

Analyses of genetic diversity in five Canadian dairy breeds using pedigree data

The issue of loss of animal genetic diversity, worldwide in general and in Canada in particular, has become noteworthy. The objective of this study was to analyze the trend in within‐breed genetic diversity and identify the major causes of loss of genetic diversity in five Canadian dairy breeds. Pedigrees were analyzed using the software EVA (evolutionary algorithm) and CFC (contribution, inbreeding, coancestry), and a FORTRAN package for pedigree analysis suited for large populations (PEDIG). The average rate of inbreeding in the last generation analyzed (2003 to 2007) was 0.93, 1.07, 1.26, 1.09 and 0.80% for Ayrshire, Brown Swiss, Canadienne, Guernsey and Milking Shorthorn, respectively, and the corresponding estimated effective population sizes were 54, 47, 40, 46 and 66, respectively. Based on coancestry coefficients, the estimated effective population sizes in the last generation were 62, 76, 43, 61 and 76, respectively. The estimated percentage of genetic diversity lost within each breed over the last four decades was 6, 7, 11, 8 and 5%, respectively. The relative proportion of genetic diversity lost due to random genetic drift in the five breeds ranged between 59.3% and 89.7%. The results indicate that each breed has lost genetic diversity over time and that the loss is gaining momentum due to increasing rates of inbreeding and reduced effective population sizes. Therefore, strategies to decrease rate of inbreeding and increase the effective population size are advised.