猪脊椎数性状候选基因研究进展

脊椎数性状是猪（Sus Scrofa）的重要经济性状,多脊椎现象是指胸腰椎总数增多。胸腰椎总数增多使猪的体型加长、产肉量增加、乳头数增多,使猪的经济价值大幅度提升。猪的脊椎数性状遗传力较高,这为选择和培育多脊椎新品系猪奠定了遗传基础。挖掘影响脊椎数性状候选基因,将其应用于分子辅助选育,可加快育成多脊椎新品种。目前猪脊椎数性状研究取得较多成果,本文就猪脊椎数性状、全基因组扫描和全基因组关联分析研究方法、猪脊椎数性状候选基因3方面内容进行阐述,以期为培育多脊椎猪提供参考。     

TGFβ3基因多态位点及其与猪脊椎数性状的关联分析

本研究旨在探索转化生长因子β3(transforming growth factor beta 3,TGFβ3)基因在大白猪×民猪构建的F2代资源群体内的多态性,并分析其多态性与猪脊椎数性状的关系。试验采用PCR技术,以F0代个体的DNA为模板,筛选TGFβ3基因外显子区的SNP,并将筛选到的SNP在F2代群体中进行验证,进而分析SNP与猪脊椎数性状的关联性。结果发现,TGFβ3基因在F0代个体中仅筛选到1个SNP位点,即SSC7:105179474GA,表现为两种基因型GG和GA。TGFβ3基因不同基因型与F2代个体脊椎数性状的关联分析表明,SSC7:105179474GA与猪肋骨数、胸腰椎数之和呈极显著相关(P0.01),与猪腰椎数无显著相关(P0.05)。χ2适合性检验发现,该位点处于Hardy-Weinberg平衡状态(P0.05)。综上所述,TGFβ3基因可能是影响猪脊椎数性状的主效基因或与主效基因连锁,SSC7:105179474GA位点有望作为提高猪脊椎数性状的分子遗传标记。     

TGFβ3基因多态位点及其与猪脊椎数性状的关联分析

本研究旨在探索转化生长因子β3（transforming growth factor beta 3，TGFβ3）基因在大白猪×民猪构建的F2代资源群体内的多态性，并分析其多态性与猪脊椎数性状的关系。试验采用PCR技术，以F0代个体的DNA为模板，筛选TGFβ3基因外显子区的SNP，并将筛选到的SNP在F2代群体中进行验证，进而分析SNP与猪脊椎数性状的关联性。结果发现，TGFβ3基因在F0代个体中仅筛选到1个SNP位点，即SSC7：105179474 G > A，表现为两种基因型GG和GA。TGFβ3基因不同基因型与F2代个体脊椎数性状的关联分析表明，SSC7：105179474 G > A与猪肋骨数、胸腰椎数之和呈极显著相关（P < 0.01），与猪腰椎数无显著相关（P > 0.05）。χ²适合性检验发现，该位点处于Hardy-Weinberg平衡状态（P > 0.05）。综上所述，TGFβ3基因可能是影响猪脊椎数性状的主效基因或与主效基因连锁，SSC7：105179474 G > A位点有望作为提高猪脊椎数性状的分子遗传标记。     

《国外畜牧科技资料》1975年1-6期总目录

概况苏联养禽业近况和存在间题杜洛克猪在美国的饲养状况斯里兰卡的畜牧生产及科学研究西德的肉牛业国外畜牧生产统计资料育种欧洲某些国家的猪育种计划芬兰家畜育种工作的组织和人工授精改良猪种用的遗传学线说家畜经济性状的变异家畜选种原理优良种畜的选择影响猪遗传改进量的因素猪的生产中基因型与环境的相互作用猪的遗传疾患猪的一些繁殖性状之间的互相关系家畜品系繁育的若干问题杂种高培羊有益经济性状的遗传力 和重复力澳大利亚绵羊育种研究肉牛品种美洲野牛和黄牛的杂交种培育成功奶牛和猪的育种新动向第一届世界家畜生产应用遗传…     

选种指数在长白猪,约克夏猪高产系选育中的应用

在家畜多性状的选择过程中，指数选择法的应用最为广泛。它根据个体多个性状的育种值合并成一个数据，以该数据代表个体总的遗传性能，也称为综合育种值。利用综合选种指数对家畜进行选育，在国外从４０年代已开始应用，我国在家畜选种上的应用也有近２０年的历史。尤其是近年来应用的比较广泛和深入，对家畜品质的改良和生产性能的提高，起到了很大促进作用，收到明显效果。长白猪、约克夏猪是我国６０年代从国外引进的优良瘦肉型品种猪，现分布全国各地，虽经多年多次引种和风土驯化，适应性增强，但生长速度和胴体瘦肉率大幅度下降，日增…     

野猪、松辽黑母猪及其杂交一代多性状功能基因分子遗传标记研究

本研究旨在应用"中芯一号"家猪分子育种基因芯片了解试验猪群重要经济性状功能基因遗传变异,为选留优秀育种个体提供有效信息。选择影响猪脂肪沉积、肉质、生长、抗病和被毛表型等性状功能基因有效突变位点作为分子遗传选育标记,以野猪、松辽黑母猪及其杂交一代共计106头个体作为实验动物模型,通过"中芯一号"猪分子育种芯片检测,对试验猪不同性状功能基因有效突变位点进行统计分析。结果表明,猪脂肪沉积性状功能基因（SCD和MYH4）有效突变位点在试验猪群中全部是肌内脂肪沉积有利基因型（CC、TT）;肉质性状功能基因（PHKG1、PRKAG3和RYR1）有效突变位点,除了21头猪携带有RYR1功能基因有效突变位点对肉质性状不利的等位基因T外（杂合基因型CT）,其他个体全部为肉质性状有利基因型（CC、GG、CC）;抗病性状功能基因MUC13有效突变位点的抗病有利等位基因纯合基因型（GG）所占比例高于杂合（GA）和不利等位基因纯合基因型（AA）;生长性状功能基因（HMGA1、VRTN和CCKAR）有效突变位点检测发现,猪群中没有增加体长趋势的HMGA1突变位点的TT基因型个体,仅有1个杂合体;肋骨数功能基因VRTN有效突变位点T等位基因频率高,对个体的胸椎数有增加趋势;功能基因CCKAR有效突变位点全部是有利于增加采食及日增重的C等位基因纯合基因型;被毛表型性状KIT功能基因有效突变位点在所有检测猪个体呈现出GG基因型,说明研究猪群中不存在影响白色被毛表型的基因突变位点,与试验猪群被毛表型结果一致。以上结果为猪群进一步育种规划提供了有益信息。     

基于高通量测序技术的山羊遗传多样性及其生产性状研究进展

近年来,高通量测序技术的规模化应用及生物信息技术的普及,极大地推动了家畜基因组学的发展,实现了分子育种标记全基因组水平的快速、精准定位,为全基因组选择育种奠定了重要基础。数千年来的驯化和选择,形成了用途多样的山羊品种,如乳用、皮用、绒用及肉用等,为人类提供了丰富的生产和生活资料。国内外学者采用高通量测序技术对山羊的遗传多样性及生产性能的遗传机制进行了研究,以期找到与山羊种质特性相关的基因,从而为山羊的遗传改良提供新的标记。作者对近五年来基于高通量测序技术研究山羊的遗传多样性和产绒、产奶、繁殖等生产性状的研究进展进行了综述,以期为评估山羊优良种质特性和与生产性状相关的优异基因定位的工作提供参考。     

MUC13基因第2内含子插入/缺失突变对基因表达和经济性状的影响

研究报道MUC13基因第2内含子的插入/缺失突变与ETEC F4导致的仔猪腹泻病密切相关,但该突变位点是否会对基因表达和经济性状(如一般抗病力、生产性状及繁殖性能等)造成影响还有待评估。本试验通过PCR方法检测大白猪群体中该突变位点的多态性,并分析其对大白猪MUC13基因mRNA表达水平、部分重要细胞因子水平(IL-1β、IL-4、IL-6、IL-8、IL-10、IFN-γ、TGF-β及TNF-α)、生产性状及繁殖性能的影响,以探究将该位点作为抗性遗传标记应用于抗病育种实践的可行性。结果表明:该位点在大白猪群体中存在3种基因型;不同基因型个体间组织mRNA表达水平、重要细胞因子水平、生产性状及1~4胎繁殖性能(总产仔数、产活仔数和断奶仔猪数)差异均不显著(P0.05)。综上所述,将MUC13基因第2内含子插入/缺失突变作为大白猪抗性遗传标记进行分子选育时,不会对机体基因表达和重要经济性状造成显著影响。本研究为将该突变位点作为大白猪抗仔猪腹泻分子选育遗传标记的可靠性提供了一定的理论依据。     

基因编辑技术在猪遗传育种中的研究进展

基因编辑是针对基因组特定的靶点序列,利用人工特异性核酸酶对靶点序列进行编辑(基因敲除、插入、替换等修饰)的技术。基因编辑技术广泛应用于生物医学研究以及农业遗传育种改良。猪作为重要的农业经济动物,是养殖最为广泛的肉用型家畜,随着人类物质需求的提高,现代养殖业需要培育更多具有优良经济性状、适应人们多样化需求的新品种。利用基因编辑技术提高猪的生产性能、抗逆性能和抗病性能是未来生猪种业发展的重要方向。本文综述了基因编辑猪在畜牧业遗传育种领域的研究进展,并展望了该领域当前面临的挑战和未来发展方向。     

洼地绵羊FecB基因多态性及与产羔数的相关性

为了研究候选基因骨形态发生蛋白受体IB(BMPR-IB)基因Fec B突变是否为影响洼地绵羊多胎性状的主效基因,试验采用PCR-RFLP分析该基因在洼地绵羊中的多态性,利用最小二乘法分析不同基因型对产羔数的影响。结果表明:在采集的111只洼地绵羊中分析BMPR-IB基因Fec B突变位点的多态性,检测到FecB~B/FecB~B、FecB~B/FecB~+、FecB~+/FecB~+3种基因型,基因型频率分别为0.432,0.514,0.054。不同基因型对产羔数的结果分析可得,FecB~B/FecB~B、FecB~B/FecB~+基因型个体的平均产羔数显著高于野生型个体的产羔数(P0.05),野生型个体也存在多羔现象,Fec B突变为洼地绵羊的多胎主效基因,但其突变野生型个体的产羔数也较高,推断洼地绵羊可能存在其他影响多羔性能的主效基因。     

Research Progress on Multi-vertebral Trait in Livestock

Multi-vertebra trait means increase of the vertebral number in animal, which is positive for livestock. Increased thoracic-lumbar vertebral number will result in improvement of carcass traits, especially carcass length, as well as economic value. Meanwhile, relatively high heritability of multi-vertebra trait is evaluated, providing genetic basis for selecting and breeding of multi-vertebra livestock. As such, individuals with multi-vertebra trait will increase production of domestic animals ultimately. Thus, study on multi-vertebra trait provides theoretical basis for breeding of meat livestock with multi-vertebra. Hitherto, multi-vertebra trait has been found in swine, sheep and bovine. Much information has been revealed in studies on multi-vertebra trait in swine; While that is limited in sheep and bovine. This review summarized variations of vertebral number, effects of multi-vertebra trait on the production traits, and genes or mutations responsible for multi-vertebra trait of livestock animal. Further, the research gap and future direction were analyzed as well.     

A global strategy of using molecular genetic information to improve genetics in livestock

Traditional breeding programmes have largely contributed to disseminate the benefits of several quantitative traits in livestock. In developing countries such as Indonesia where animal population scattered throughout the country, it is difficult to invest for molecular research. On the other side, yet, it is worthy asset for breeding purposes. Based on theory and evidence, it has been proved that those scattered population evolved different genetic adaptations in response to a given natural pressure selection. A global strategy can be applied to the use of molecular genetic information for identification of economically important value. The use of genetic markers or more effective of marker-assisted selection (MAS) for desired important traits would be more valuable and useful and even more efficient in important trait selection of superior livestock. DNA marker technology would be very useful when applied for quantitative trait identification. Marker-assisted selection can be used for enhancing conventional breeding and works best for the traits with low heritability such as in reproductive traits and disease resistance. Application of conventional breeding for lower heredity traits would not be efficient because of waiting longer for generation interval, expensive in measurements, more population and more employees needed. Study of quantitative trait loci mapping is early investment to improve genetic merit. It can be performed once but can be used for exploring many genetic traits with economically important values. An effective option is biotechnology application in livestock for the development of genetic varieties such as stress tolerance, growth and carcass traits. Application of biotechnology approaches will enable improvement in productivity, reduction in costs, enrichment of milk compositions and extension of shelf life products.     

基因组选择及其在羊育种中的应用研究进展

数量性状是羊育种中的重要性状,受微效多基因控制、遗传力低,而传统育种方法难以提高羊的育种效率。提高动物育种效率对于选种选配工作和经济生产效益至关重要。随着育种新技术的不断革新与发展,基因组选择(genomic selection, GS)方法已成为育种技术中强大的工具,且已成功运用于个体经济价值较大的物种中,其具有缩短世代间隔、提高育种准确性、减少生产成本、提高畜禽经济效益等优势。近年来,由于基因组技术的不断成熟和各个统计模型的升级优化,以及高密度SNP芯片价格的下调,报告有关于基因组选择育种的实证和模拟研究层出不穷,且基因组选择技术已在羊育种中逐步开展,特别是在羊的重要性状中已有不少报道。由于羊的品种较多,地方性状差异化较大,个体经济价值略低,尽管基因组育种的新技术已经非常成熟,但目前仍没有在羊育种中大范围普及。为了更全面地了解该技术在羊育种中的研究现状,且基于选种选配的重要地位,作者就基因组选择在羊育种中的研究进展展开综述,主要从表型测定、基因分型、不同模型方面介绍了基因组选择在羊的重要性状中的应用和现状,讨论了其优势与挑战,并展望了基因组选择的未来发展方向。     

Production of transgenic livestock: promise fulfilled

The introduction of specific genes into the genome of farm animals and its stable incorporation into the germ line has been a major technological advance in agriculture. Transgenic technology provides a method to rapidly introduce "new" genes into cattle, swine, sheep, and goats without crossbreeding. It is a more extreme methodology, but in essence, not really different from crossbreeding or genetic selection in its result. Methods to produce transgenic animals have been available for more than 20 yr, yet recently lines of transgenic livestock have been developed that have the potential to improve animal agriculture and benefit producers and/or consumers. There are a number of methods that can be used to produce transgenic animals. However, the primary method to date has been the microinjection of genes into the pronuclei of zygotes. This method is one of an array of rapidly developing transgenic methodologies. Another method that has enjoyed recent success is that of nuclear transfer or "cloning." The use of this technique to produce transgenic livestock will profoundly affect the use of transgenic technology in livestock production. Cell-based, nuclear transfer or cloning strategies have several distinct advantages for use in the production of transgenic livestock that cannot be attained using pronuclear injection of DNA. Practical applications of transgenesis in livestock production include enhanced prolificacy and reproductive performance, increased feed utilization and growth rate, improved carcass composition, improved milk production and/or composition, and increased disease resistance. One practical application of transgenics in swine production is to improve milk production and/or composition. To address the problem of low milk production, transgenic swine over-expressing the milk protein bovine alpha-lactalbumin were developed and characterized. The outcomes assessed were milk composition, milk yield, and piglet growth. Our results indicate that transgenic overexpression of milk proteins may provide a means to improve swine lactation performance.     

The Main Research Fields and Progress of Livestock Epigenetics

Epigenetics means that there are heritable changes in gene expression while without a change in DNA sequence.In the recent years,the researches of epigenetic regulation on livestock field have developed rapidly.The main studied domestic animals include poultry,swine,bovine,sheep and goat,thus a new subject——livestock epigenetics is developing.Livestock epigenetics mainly uses various kinds of epigenetic modifications involved in DNA methylation,histone modification and non-coding RNAs regulation to study livestock growth and development,disease resistance,reproduction and economic traits,and so on.Here,we reviewed the mainly research fields and progress on livestock epigenetics,the trends of livestock epigenetics studies were also discussed to comprehensively understand the molecular basis of the complex traits formation of livestock and poultry,which greatly broadened the research and strategy to improve the economic traits of livestock and poultry.     

CRISPR/Cas9基因编辑技术在家畜育种新材料创制中的研究进展

规律性成簇间隔的短回文重复序列/CRISPR相关蛋白（clustered regularly interspaced short palindromic repeats/CRISPR-associated,CRISPR/Cas）系统是最新一代能对细胞或生物体基因组进行精准编辑的基因工程技术,与前两代基因编辑技术ZFN和TALEN相比,CRISPR/Cas具有应用成本低、适用编辑范围广、打靶效率高、操作简单、可支持多位点操作等诸多优点。近年来,CRISPR/Cas系统尤其是Type II类、A型的CRISPR/Cas9系统已经作为最新一代基因编辑技术被广泛应用于提高家畜繁殖效率、生产性能、抗病性以及动物模型构建等研究中,并创制了一批基因编辑牛羊育种新材料。本文就其发展历程、技术改造和优化最新进展以及在家畜繁殖性状、生产性状和抗病性状等方面的研究应用进行综述,重点介绍了该系统在家畜育种学研究中已取得的最新进展,并就CRISPR/Cas9基因编辑技术在家畜育种应用中现存的问题及其应用前景进行简要论述。     

牛羊多胎性状的分子遗传基础研究

本研究采用了RAPD、PCR RFLP、微卫星、PCR SSCP、序列分析等方法对2个牛品种(秦川牛和荷斯坦奶牛共60头)、6个中国固有绵羊品种(多胎品种小尾寒羊,双胎品种大尾寒羊,单胎品种兰州大尾羊、蒙古羊、同羊和哈萨克羊共197余只`进行了分子遗传基础研究,旨在寻找牛羊多胎性状合适的分子标记,为进一步对牛双胎基因、绵羊多胎基因的探索和高繁殖率牛羊的选育提供科学依据.     

Genetic evaluation of carcass yield using ultrasound measures on young replacement beef cattle

Live weight and ultrasound measures of fat thickness and longissimus muscle area were available on 404 yearling bulls and 514 heifers, and carcass measures of weight, longissimus muscle area, and fat thickness were available on 235 steers. Breeding values were initially estimated for carcass weight, longissimus muscle area, and fat thickness using only steer carcass data. Breeding values were also estimated for weight and ultrasound muscle area and fat thickness using live animal data from bulls and heifers, with traits considered sex-specific. The combination of live animal and carcass data were also used to estimate breeding values in a full animal model. Breeding values from the carcass model were less accurate and distributed more closely around zero than those from the live data model, which could at least partially be explained by differences in relative amounts of data and in phenotypic mean and heritability. Adding live animal data to evaluation models increased the average accuracy of carcass trait breeding values 91, 75, and 51% for carcass weight, longissimus muscle area, and fat thickness, respectively. Rank correlations between breeding values estimated with carcass vs live animal data were low to moderate, ranging from 0.16 to 0.43. Significant rank changes were noted when breeding values for similar traits were estimated exclusively with live animal vs carcass data. Carcass trait breeding values estimated with both live animal and carcass data were most accurate, and rank correlations reflected the relative contribution of carcass data and their live animal indicators. The addition of live animal data to genetic evaluation of carcass traits resulted in the most significant carcass trait breeding value accuracy increases for young replacements that had not yet produced progeny with carcass data.     

The evidence of associations between prion protein genotype and production, reproduction, and health traits in sheep

The EU Commission issued a regulation in 2003, which requires all member states to implement a breeding programme for resistance to transmissible spongiform encephalopathies in sheep by selecting for specific alleles of the prion protein (PrP) gene. A key concern with regard to this regulation was that the intensive selection programmes, designed to increase resistance to scrapie, may have a negative impact on a range of other economically important production, reproduction, and disease traits in sheep. Such problems could arise for a number of reasons. Firstly, a number of breeds have a low frequency of the resistant PrP allele. Secondly, there may be a negative association between the resistant allele and animal performance. Thirdly, selection for scrapie resistance may reduce the rate of improvement towards current breeding goals. The evidence concerning the relationship between PrP genotype and reproduction, production, and disease traits is the subject of this review. We conclude that there is no evidence for a negative association between PrP genotype and reproduction traits (e.g. litter size), lamb performance traits (e.g. growth rate, conformation, carcass composition) or milk production. There is, however, a distinct paucity of information on the relationship between the PrP gene and disease traits. In this context it is noted that there are a number of genes located on chromosome 13, in close proximity to the PrP gene, that are involved in intracellular cell signalling, apoptosis, phagocytosis, and immune function. Thus further direct studies of key disease traits associated with sheep production systems are warranted.     

Application of ultrasound for genetic improvement.

Genetic improvement programs for livestock would be enhanced by the ability to accurately and easily measure body composition of live animals or to make measurements at anatomical reference points that can be used to accurately predict body composition. Advances in ultrasonic technology, such as real-time imagery and portable ultrasound units, have renewed interest among animal scientists working with genetic improvement programs and the livestock industry groups they serve. Ultrasound has been used for more than 30 yr and, for swine, has been demonstrated to improve significantly the accuracy of predicting body composition. However, many studies have shown less success in improving prediction of body composition from the use of ultrasonics to measure live beef cattle and sheep. The swine industry probably will be the first to benefit measurably from use of ultrasound technology in large-scale genetic improvement programs for carcass merit. Considerable research and development is needed before ultrasound technology can be effectively used in similar large-scale programs in the beef cattle and sheep industries.