绵羊基因组研究进展

过去几年中,家畜基因组计划取得了巨大进展。已经构建了猪、鸡、牛、绵羊和马的遗传图谱,其遗传标记间距在5-20cM。这些图谱对于家畜中与重要经济性状相关的基因或遗传标记的鉴定非常重要。文章从绵羊的遗传图谱、物理图谱、重要经济性状基因及QTL定位等方面对绵羊基因组的研究进展作了简要阐述。     

苜蓿遗传连锁图谱构建研究进展

高密度分子标记的连锁遗传图谱对分析植物遗传变异、目标性状的标记、数量性状的定位和分子标记辅助育种均具有重要价值.由于大多数苜蓿的多倍性和高度异质特点,苜蓿遗传连锁图谱的构建相对复杂,目前,已经产生了一定数量的苜蓿遗传连锁图谱.本文简要综述了苜蓿遗传图谱研究现状和常用策略,提出了构建高质量苜蓿遗传图谱的建议.     

畜禽遗传图谱及其在动物育种中的应用

自20世纪90年代欧美等国启动动物基因组计划以来,畜禽遗传图谱的构建取得了长足的进展,并对畜禽的育种改良正在和即将起着深远的影响。本文综述了用于畜禽遗传图谱构建研究的主要DNA分子标记,遗传图谱构建的基本程序,猪、牛、绵羊和鸡等主要畜禽遗传图谱研究的进展,并对遗传图谱在畜禽基因定位和标记辅助选择方面的应用进行了相应的讨论。     

牧草遗传连锁图谱构建研究概述

高密度分子连锁遗传图谱对分析植物遗传变异、标记目标性状、数量性状定位和分子辅助选择改良性状均具重要价值。由于大多数牧草的多倍性和高度异质特点,牧草遗传连锁图谱的构建相对复杂。目前,一定数量牧草的遗传连锁图谱已经产生。本文简要综述了牧草遗传图谱研究现状和常用策略,提出了构建高质量牧草遗传图谱的建议。     

基因图谱的构建及其在动物遗传育种中的应用

本文阐述了遗传图谱、物理图谱的概念，着重介绍了利用人这标记构建遗传图谱和物理图谱的方法，并阐述了基因图谱在家畜育种中的应用。     

基于SRAP分子标记构建的菊苣遗传连锁图谱

基于SRAP标记,以遗传关系和表型差异大的菊苣亲本PI 651947和PI 652007杂交获得的84个F₁单株为作图群体,进行连锁图谱的构建。采用Map Manager QTX b20软件进行连锁分析,分别构建了PI 651947和PI 652007的分子连锁框架图,共获得77个SRAP标记,其中父本遗传图谱涉及4个连锁群,包含19个标记,图谱总长为450.9 cM,标记间平均图距为23.7 cM。母本遗传图谱涉及13个连锁群,包含58个标记,图谱总长为1404.8 cM,标记间平均图距为24.2 cM。研究结果可为菊苣重要农艺性状QTL定位奠定基础,为菊苣分子育种研究提供了基础信息。     

苜蓿遗传图谱构建及其应用

苜蓿是世界上最重要的豆科牧草之一,苜蓿遗传图谱构建是解析重要农艺性状(QTL)遗传特性和基因连锁分析的前提条件。由于复杂的四体遗传特性,目前已构建成功的苜蓿遗传图谱大多数是二倍体苜蓿,四倍体栽培苜蓿遗传图谱较少。本研究就苜蓿遗传图谱构建研究已取得的成就、图谱绘制过程中的限制因素、解决策略和已有图谱的特征等问题进行了回顾和讨论;对苜蓿遗传图谱研究,特别是构建四倍体苜蓿遗传图谱,在揭示苜蓿遗传特性和定位重要农艺性状相关基因位点(QTL)方面的应用现状和重要意义进行了论述,就苜蓿遗传图谱在苜蓿分子标记辅助育种中的应用前景进行了展望,并就我国苜蓿育种现状和开展苜蓿遗传图谱构建研究提出了一些建议。     

牛连锁图谱和比较基因图谱作图现状

一张覆盖全基因组的有足够信息量标记的遗传图谱 ,是检测经济性状QTL的一个前提条件 ;比较基因作图则是确定经济性状候选基因的有效工具。文章简述了牛的这两种图谱的作图现状。     

紫花苜蓿QTL与全基因组选择研究进展及其应用

四倍体紫花苜蓿是重要的豆科牧草之一,由于其复杂的遗传背景与二倍体作物相比遗传作图与重要性状数量性状位点(quantitative trait locus,QTL)定位研究相对滞后。然而,二倍体苜蓿的相关研究起步较早,已经建立了高密度遗传图谱和物理图谱,这些研究为四倍体苜蓿遗传作图与QTL定位奠定了基础。随着第三代分子标记与测序技术的快速发展,极大地促进了四倍体苜蓿的高密度遗传图谱构建与QTL定位研究,并借助分子标记辅助育种技术对提高苜蓿选育效率,加速育种进程具有重要意义。本文对苜蓿遗传图谱构建与QTL定位研究及发展趋势进行了总结,并对苜蓿关联作图与全基因组选择的研究进展及应用前景加以概述,旨在为读者就相关研究领域有较全面的了解。     

分子遗传标记技术及其在动物育种中的研究进展

遗传标记经历了从传统的标记即形态学标记、细胞学标记、生物化学标记到现代分子标记的发展,分子标记具有很多优势,也促进了动植物育种、人类医学、基因定位以及构建遗传图谱的改革。遗传标记能应用于畜禽的遗传多样性分析、种质资源的鉴定、亲缘关系的研究、遗传图谱的构建、分子标记辅助选择和QTL定位等领域,文章主要综述了分子标记在标记辅助选择的应用。     

A male bovine linkage map for the ADR granddaughter design

The aim of this paper is to present the construction of a male genetic linkage map as a result of the bovine genome mapping project, which is a common effort of the German cattle breeding federation (ADR), four animal breeding institutes, three blood group laboratories and two animal data and breeding value evaluation centres. In total 20 grandsires with 1074 sires were provided from the German cattle population as reference families, 16 of these paternal half‐sib groups are German Holstein families (DH), three are German Simmental (ST) families, and one is a Brown Swiss family (BS). Of 265 markers included in the linkage map, 248 were microsatellite markers, five were bovine blood group systems, eight SSCP markers and four proteins and enzymes. More than 239 000 genotypes resulted from typing the offspring for the respective markers and these were used for the construction of the map. On average 478 informative meioses were provided from each marker of the map. The summarized map length over all chromosomes was 3135.1 cM with an average interval size of 13.34 cM. About 17, 35.7 and 79.1% of the map intervals showed a maximum genetic distance between the adjacent markers of 5, 10 and 20 cM, respectively. The number of loci ranged from two (pseudoautosomal region of the sex chromosome, BTAY) to 15 (BTA23) with an average of 8.8 markers per chromosome. Comparing the length of the chromosomes shows variation from 49.6 cM for BTA26 to 190.5 cM for BTA1 with a mean of 107.7 cM for all autosomes of the genetic linkage map. It was possible to identify chromosomal discrepancies in locus order and map intervals by comparison with other published maps. The map provided sufficient marker density to serve as a useful tool for a scan of segregating quantitative trait loci.     

西门塔尔牛与我国地方黄牛的杂种优势预测分析

旨在利用覆盖全基因组和与性状相关的SNPs标记分析西门塔尔牛和地方黄牛两个亲本群体的遗传结构,通过亲本种群之间的遗传距离预测不同杂交组合在生长、胴体和肉质性状上的杂种优势.本研究选择来自内蒙古锡林郭勒盟乌拉盖管理区牧场的1 222头西门塔尔牛和8个地方黄牛品种190头共组成8个杂交组合,对亲本群体进行遗传结构分析.利用...     

牛基因组研究进展

本文分牛基因组遗传图谱、物理图谱、全基因组序列图与转录组研究四个部分介绍了牛基因组学研究进展.最新的牛遗传连锁图谱由4 585个标记组成,平均图距精确到1.2 cM,是研究牛数量性状位点、定位克隆生产性状相关基因进行分子辅助育种的蓝图.基于限制性酶切指纹图与末端测序技术对294 651个BAC克隆分析拼接成的物理图谱,覆盖约15.8倍基因组,为牛全基因组测序和组装提供了框架.融合了全基因组鸟枪法和逐步克隆法绘制的牛基因组草图,包含了26 052 388个可用测序读长,覆盖约7.0倍基因组,拼接成2.87 Gb的基因组序列.牛各个组织器官的cDNA文库构建和EST测序以及基因芯片方面的基因转录和表达的研究,将阐释更多的泌乳、繁殖、产肉和疾病抵御力等重要性状相关功能基因,从而将更多的基因应用到牛的分子辅助育种上.     

我国家蚕基因组的最新研究——对家蚕基因组精细图和40个蚕类基因组遗传变异图的解读

2008年12月,西南大学家蚕基因组研究团队宣布了世界上第1张家蚕基因组精细图谱的诞生。家蚕基因组精细图和2003年发布的家蚕基因组框架图相比,具有基因覆盖度高、基因组组装更加完整、基因鉴定更加准确等特点。2009年,该研究团队在家蚕基因组精细图的基础上,选取具有代表性的29个家蚕突变品系和11个不同地理来源的中国野桑蚕品系进行了全基因组重测序与序列比较分析,共获得了29个家蚕突变品系和11个中国野桑蚕地理品系的全基因组序列,绘制完成了世界上第1张基因组水平上的蚕类单碱基遗传变异图谱,同时还发现了驯化对家蚕生物学性状影响的基因组印记,从全基因组水平上揭示了家蚕的起源进化。2009年8月,《Science》杂志发表了西南大学的研究论文"40个蚕类基因组的重测序揭示了家蚕的驯化事件及驯化相关基因",标志着家蚕基因组计划进入一个新的历史阶段。     

Development of genome engineering technologies in cattle: from random to specific

The production of transgenic farm animals(e.g., cattle) via genome engineering for the gain or loss of gene functions is an important undertaking. In the initial stages of genome engineering, DNA micro-injection into one-cell stage embryos(zygotes) followed by embryo transfer into a recipient was performed because of the ease of the procedure.However, as this approach resulted in severe mosaicism and has a low efficiency, it is not typically employed in the cattle as priority, unlike in mice. To overcome the above issue with micro-injection in cattle, somatic cell nuclear transfer(SCNT) was introduced and successfully used to produce cloned livestock. The application of SCNT for the production of transgenic livestock represents a significant advancement, but its development speed is relatively slow because of abnormal reprogramming and low gene targeting efficiency. Recent genome editing technologies(e.g.,ZFN, TALEN, and CRISPR-Cas9) have been rapidly adapted for applications in cattle and great results have been achieved in several fields such as disease models and bioreactors. In the future, genome engineering technologies wil accelerate our understanding of genetic traits in bovine and wil be readily adapted for bio-medical applications in cattle.     

Non-lactational traits of importance in dairy cows and applications for emerging biotechnologies

Dairy cattle have traditionally been selected for their ability to produce milk and milk components. The traditional single-minded approach to selection of dairy cattle has now changed and secondary traits are being included in selection indices by decreasing the emphasis on production. Greater emphasis on non-production traits reflects the industry's desire for functional dairy cattle. Six broad categories of non-lactational traits are discussed in this review. They are: type; growth, body size and composition; efficiency of feed utilisation; disease resistance, e.g. udder health as measured by somatic cell score; reproduction; and management. Most of these traits can be found within selection indices worldwide, although relative emphasis varies.

The non-lactational traits mentioned above are quantitative, meaning that the phenotype in the whole animal represents the sum of lesser traits that cannot be easily measured. The physiological mechanisms that underlie quantitative traits are extremely complex. Genetic selection can be applied to quantitative traits but it is difficult to link successful genetic selection with the underlying physiological mechanisms. The importance that the bovine genome sequence will play in the future of the genetics of dairy cattle cannot be understated. Completing the bovine genome sequence is the first step towards modernising our approach to the genetics of dairy cattle.

Finding genes in the genome is difficult and scanning billions of base pairs of DNA is an imperfect task. The function of most genes is either unknown or incompletely understood. Combining all of the information into a useable format is known as bioinformatics. At the present time, our capacity to generate information is great but our capacity to understand the information is small. The important information resides within subtle changes in gene expression and within the cumulative effect that these have.

Traditional methods of genetic selection in dairy cattle will be used for the foreseeable future. Most non-lactational traits are heritable and will be included in selection indices if the traits have value. The long-term prognosis for genome science is good but advances will take time. Genetic selection in the genome era will be different because DNA sequence analysis may replace traditional methods of genetic selection.     

隆林牛与郏县红牛线粒体DNA全基因组遗传多样性比较研究

摘　要：［目的］本研究旨在从基因组水平探究隆林牛和郏县红牛的线粒体DNA（mtDNA）全基因组遗传多样性与母系起源,并对2个黄牛品种的mtDNA全基因组遗传多样性进行比较分析。［方法］采用全基因组重测序及生物信息学方法。［结果］在15头隆林牛和28头郏县红牛mtDNA全基因组序列中,共检测到36种单倍型,其中郏县红牛有26种单倍型,隆林牛仅有8种单倍型,2个黄牛品种共享2种单倍型。郏县红牛和隆林牛的平均单倍型多样度（Hd）分别为1.000和0.943,平均核苷酸多样度（Pi）分别为0.0080和0.0053,表明其遗传多样性丰富。构建的系统发育树表明,隆林牛和郏县红牛具有瘤牛和普通牛两个母系支系。［结论］隆林牛以瘤牛起源为主,郏县红牛为普通牛与瘤牛的混合起源,这2个地方黄牛品种具有独特的母系遗传信息,表现出明显的母系遗传差异。     

Non-lactational traits of importance in dairy cows and applications for emerging biotechnologies

Dairy cattle have traditionally been selected for their ability to produce milk and milk components. The traditional single-minded approach to selection of dairy cattle has now changed and secondary traits are being included in selection indices by decreasing the emphasis on production. Greater emphasis on non-production traits reflects the industry's desire for functional dairy cattle. Six broad categories of non-lactational traits are discussed in this review. They are: type; growth, body size and composition; efficiency of feed utilisation; disease resistance, e.g. udder health as measured by somatic cell score; reproduction; and management. Most of these traits can be found within selection indices worldwide, although relative emphasis varies. The non-lactational traits mentioned above are quantitative, meaning that the phenotype in the whole animal represents the sum of lesser traits that cannot be easily measured. The physiological mechanisms that underlie quantitative traits are extremely complex. Genetic selection can be applied to quantitative traits but it is difficult to link successful genetic selection with the underlying physiological mechanisms. The importance that the bovine genome sequence will play in the future of the genetics of dairy cattle cannot be understated. Completing the bovine genome sequence is the first step towards modernising our approach to the genetics of dairy cattle. Finding genes in the genome is difficult and scanning billions of base pairs of DNA is an imperfect task. The function of most genes is either unknown or incompletely understood. Combining all of the information into a useable format is known as bioinformatics. At the present time, our capacity to generate information is great but our capacity to understand the information is small. The important information resides within subtle changes in gene expression and within the cumulative effect that these have. Traditional methods of genetic selection in dairy cattle will be used for the foreseeable future. Most non-lactational traits are heritable and will be included in selection indices if the traits have value. The long-term prognosis for genome science is good but advances will take time. Genetic selection in the genome era will be different because DNA sequence analysis may replace traditional methods of genetic selection.     

Confirmation of assignment of the bovine K-casein locus by PCR.

The provision of a bovine gene map will allow the ready identification of genetic disease in cattle and will lead to the identification of the genetic loci responsible for quantitative traits of economic importance. An extension of the polymerase chain reaction to the identification of linkage in bovine-Chinese hamster cell hybrids has improved the speed and facility of the assignment of genes to linkage groups and thus makes it easier to achieve a bovine linkage map.     

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。