分子标记及其在标记辅助选择中的应用

运用分子标记来进行标记辅助选择，已经成为当今家畜育种的一种趋势。笔者对目前常见的几种分子标记进行了简要介绍，并就分子标记在标记辅助选择中的应用，特别就分子标记在标记辅助选择中分子标记图谱的构建、分子标记的筛选、QTL定位和与分子标记的连锁分析3个方面的应用作了较详尽的综述。     

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。     

分子标记在家禽研究中的应用进展

分子标记是继形态标记、细胞标记和生化标记之后发展起来的一种比较理想的遗传标记技术.目前在动物遗传中广泛使用的分子标记主要有RFLP、DNA指纹、AFLP、SSR、mtDNA、SNP和EST标记,本文综述了这些DNA分子标记的原理、特点及其在家禽中的应用情况.随着分子标记手段的不断更新和完善,更为有效和便捷的分子标记技术将应用于家禽遗传育种的应用研究中.     

奶牛精液品质性状的分子标记技术研究进展

繁殖力下降是制约当代奶业发展的重要因素,选育高繁殖力种公牛是解决这一问题的关键。有报道称奶牛的产奶性能和繁殖力呈负相关,而传统选育方法对繁殖力这一低遗传力性状的选择效果较差。分子标记辅助选择是根据分子标记信息对动植物个体进行选择,对于一些低遗传力、早期难以测定表型值、测量费用昂贵和线性表现的性状的选择有明显的优势。分子标记主要包括DNA分子标记、蛋白质分子标记、RNA分子标记、表观遗传分子标记和代谢产物分子标记等。这些分子标记的开发和应用,极大地促进了遗传育种工作进程,并且随着分子生物学技术的发展,将会有越来越多的分子标记被开发和利用。     

分子遗传标记在奶牛标记辅助选择中的应用

分子标记是目前研究比较多的一类遗传标记,遗传标记主要包括有形态学标记、细胞学标记、生化标记和分子标记等.前3种是基因表达的结果,是对基因差异的间接反映,易受环境和其他因素的影响.而分子标记直接从DNA分子水平上反映差异,不受环境、发育阶段、组织等的影响,稳定可靠,多态性好,因而在家畜育种中被广泛利用,特别是在标记辅助选择中.标记辅助选择利用分子标记与QTL之间的连锁不平衡,通过对分子标记的选择来实现对QTL的选择达到家畜育种目的.     

一种新型的分子标记-SCARs验证王浆高产蜜蜂的 RAPD分子标记-W316bp的研究

为了验证王浆高产蜜蜂的RAPD分子标记-W316bp正确性，采用了新型分子标记-SCARs，研究结果获得的SCARs分子标记与原来RAPD分子标记有一致的显性行为，从而完成了RAPD分子标记转变成SCARs分子标记技术。     

分子标记在动物育种中的应用

遗传标记有着悠久的历史,经历了形态学标记、细胞学标记、生物化学标记和现代DNA分子标记(简称分子标记)。遗传标记是指一些等位基因或遗传物质,其表型易于识别,且遵循简单的孟德尔遗传规律。所谓分子遗传标记,必须能够证实它既涉及到一个可遗传的性状,又要能将它定位到基因组上的     

DNA分子标记技术在白僵菌上的应用研究进展

分子标记是继形态标记、细胞标记和生化标记之后发展起来的一种比较理想的遗传标记技术。分子标记技术大大促进了白僵菌有关研究的发展。本文介绍了4种常用的分子标记技术及其在白僵菌中的应用情况。     

蜜蜂分子标记研究进展

分子标记是指可遗传的、能被定位和识别的DNA序列,广义的分子标记还包括蛋白质等生物物质,是DNA水平遗传多态性的直观映射。目前分子标记已被运用在动植物及微生物的基因定位、物种起源和遗传育种等研究上,蜜蜂领域在种类鉴定和物种筛选等方面也有广泛研究。简要介绍分子标记的种类及其在蜜蜂上的应用现状,为进一步开展蜜蜂分子标记相关工作提供参考。     

猪分子育种研究进展

分子育种主要是一种利用DNA水平上的分子标记对生物群体进行遗传改良。动物分子育种方法主要包括标记辅助育种、转基因育种和体细胞克隆育种。本文主要从标记辅助育种和转基因育种两个方面综述猪分子育种的研究进展。     

猪育种中的选择性状

对特定性状的选择是最重要的育种措施之一。作者简要综述了猪的繁殖、生长肥育、胴体、肉质、次级性状和体形外貌等性状的具体选择策略及其研究进展。     

牛生长性状、肉质性状和胴体性状间典型相关分析

通过对牛生长性状、肉质性状和胴体性状指标的研究,分析3组性状组内及组间的相关性,揭示牛不同类型性状间的相互影响。测量记录327头牛3组性状的表型值,利用简单相关分析和典型相关分析对3组性状相关性进行深入研究。17个性状间共有74对存在极显著简单相关(P0.01),多数相关系数低于0.5。典型相关分析结果表明,3组性状间第一、第二和第三典型相关系数均达到极显著水平(P0.001),其中生长性状与肉质性状间、生长性状与胴体性状间、肉质性状与胴体性状间的第一和第二典型相关系数分别为0.525和0.350、0.993和0.623、0.698和0.394。结果显示,典型相关分析比简单相关能更准确、全面反映3组性状间的相关关系,为肉牛的选育提供科学依据。     

中国地方鸡生态因子和经济性状的相关性分析

试验旨在研究中国地方鸡品种生长所在地的生态因子和鸡的经济性状（体尺性状和屠宰性状）的相关性,探讨生态因子、体尺性状和屠宰性状3组性状之间的相关关系,揭示其内在联系。对中国107个地方鸡品种生长所在地的6个生态因子及其8个体尺性状、8个屠宰性状进行了简单相关分析和典型相关分析（CCA）。结果表明,生态因子和屠宰性状两组性状间的第1个典型相关系数为0.536（P < 0.01）,贡献率55.046%,说明这两组性状间的相关性主要是由年平均气温和屠体重之间密切相关引起的,年平均气温越低,鸡的屠体重越高。生态因子和体尺性状两组性状间的第1个典型相关系数为0.679（P < 0.01）,贡献率54.118%,纬度和胫围相关性最大,纬度越高,胫围越小;第2个典型相关系数为0.556（P < 0.05）,贡献率28.251%,无霜期和龙骨长相关性最大,无霜期越长,龙骨长越长。体尺性状和屠宰性状两组性状间的第1个典型相关系数为0.901（P < 0.01）,贡献率81.063%,说明这两组性状间的相关性主要是由龙骨长和屠体重之间密切相关引起的,龙骨长越长,鸡的屠体重越大。     

Genetic correlations between competition traits and traits scored at breeding field-tests in Icelandic horses

Relationships between breeding field-test traits and competition traits were studied to investigate whether the latter could be usefully included in the genetic evaluation of Icelandic horses. The current method of genetic evaluation is based on records from breeding field-tests only. The breeding field-test data included 16 401 individual records of Icelandic horses evaluated in 11 countries during 1990–2005. Competition results included 18 982 records of 3790 horses competing in sport and gæðinga competitions in Iceland and Sweden during 1998–2004. In the breeding field-tests, eight conformation traits and eight riding ability traits were scored; height of withers was also recorded. These traits were analysed together with the competition traits tölt(comp), 4-gait, 5-gait and pace test, in bivariate analyses. Animal models were used; the fixed effects for breeding field-test traits included sex by age interaction and country by year interaction. For the competition traits the model included fixed effects of sex, age and event, and a random permanent environmental effect. Estimated heritabilities and genetic correlations for breeding field-test traits were consistent with earlier results; heritabilities ranged from 0.20 to 0.67, and moderate to high genetic correlations were estimated between many of the riding ability traits, and between riding ability traits and some conformation traits. The estimated heritabilities for competition traits were about 0.20, and genetic correlations between competition traits varied from − 0.12 to 1.00. In general, high genetic correlations were estimated between breeding field-test riding ability traits and competition traits. Moderately positive genetic correlations were found between some breeding field-test conformation traits and competition traits. Competition traits add information relating to the breeding goal of the Icelandic horse; they should therefore be added to genetic evaluation in future.     

Correlation Analysis of Ecological Traits and Economic Traits for Chinese Native Chicken Breeds

The objective of this study was to investigate the correlation of ecological traits on body size traits and economic traits (body size traits and slaughter traits) in Chinese native chicken breeds and reveal the essential connection of three group traits.In this study,simple correlation analysis and canonical correlation analysis (CCA) were applied to estimate the relationship between local 6 ecological traits and 8 body size traits,6 ecological traits and 8 slaughter traits,8 body size traits and 8 slaughter traits of Chinese native chicken breeds.The result of ecological traits and slaughter traits suggested that the first canonical correlation coefficient was 0.536 (P < 0.01),the value of pct was 55.046% for the total correlation information.It showed that the correlation between two sets of traits mainly by mean annual temperature and dressed weight closely related to the cause,the lower mean annual temperature,the heavier dressed weight.The result of ecological traits and body size traits suggested that the first canonical correlation coefficient was 0.679 (P < 0.01),the value of pct was 54.118%,for the total correlation information.It showed that the correlation between two sets of traits mainly by latitude and shank girth closely related to the cause,the higher latitude,the smaller shank girth.The second canonical correlation coefficient was 0.556 (P < 0.05),the value of pct was 28.251% for the total correlation information.It showed that the correlation between two sets of traits mainly by forst free period and chest bone length closely related to the cause,the longer forst free period,the longer chest bone length.The result of body size traits and slaughter traits suggested that the first canonical correlation coefficient was 0.901 (P < 0.01),the value of pct was 81.063% for the total correlation information.It showed that the correlation between two sets of traits mainly by chest bone length and dressed weight closely related to the cause,the longer chest bone length,the greater dressed weight.     

牛血液蛋白多态性与数量性状的关系

血液蛋白多态性在选种中可视为一类附加性状。数量性状是由许多彼此独立的基因作用的结果 ,每个基因对性状的作用甚微 ,但遗传作用的机制仍服从孟德尔规律。牛的生产性能如产奶性能、生长性能和繁殖性能是通过有关生理活动来实现的 ,这涉及到酶、蛋白质等一系列生物活性物质的功能发挥 ,由于蛋白质 (酶 )多态性等生化性状与生同来 ,终生保持相对稳定 ,对外界环境保持相对独立性 ,如能找到生化性状对生产性能的预示物 ,就可提早选种 ,加快育种进度。本文综述了血液中血红蛋白、运铁蛋白、血清白蛋白位点的不同基因型多态性与产奶性能、繁殖性能、生长性能、疾病发生的研究进展情况     

奶牛生长性状研究进展与展望

近年来,生长性状在奶牛育种中备受关注,随着对奶牛生长性状研究的日益深入,其与重要经济性状间的相关性逐渐凸显出来,对奶牛的育种工作也变得越来越重要。本文就奶牛生长性状定义、遗传参数、与经济性状的关联、生长性状QTL定位、GWAS分析等方面进行了综述,并明确了生长性状在奶牛未来育种中的地位。     

中国肉用西门塔尔牛育种目标性状的选择及其经济权重的测算

为了选育中国西门塔尔牛肉用品系,本研究从中国肉用西门塔尔牛育种实践出发,确定了适应当前中国肉用西门塔尔牛的育种目标性状和选择性状。采用差额法计算出各目标性状的边际效益,并通过各目标性状表型值的遗传标准差校正边际效益,得到相应育种目标性状的经济权重。结果表明,中国肉用西门塔尔牛近期的育种目标性状主要包括生长发育性状（断奶重、育肥期日增重、18月龄体重）、胴体性状（胴体品质、屠宰率、净肉率）及繁殖性状（初产年龄、产犊间隔和留群时间）。在现有市场和生产条件下,上述育种目标性状的边际效益分别为17.93元/kg、16.2元/kg、7.17元/kg、297.99元/级、497.82元/%、594.46元/%、-3.62元/d、-26.55元/d、232.75元/y,3类性状中生长发育性状、胴体性状及繁殖性状的经济权重之比为31.49%：15.86%：52.65%,约为2：1：3,繁殖性状占总经济权重最高,其次是生长发育性状和胴体性状。综上所述,在中国肉用西门塔尔牛育种过程中,繁殖性状具有最重要的地位,需加强繁殖性状的选择力度。     

Genetic correlations for foal and studbook traits with racing traits and implications for selection strategies in the Finnhorse and Standardbred trotter

Genetic correlations for body measurements and conformation and functional traits in foals and studbook horses with racing traits were estimated in the Finnhorse and Standardbred. Genetic response and accuracy were estimated using records of animal, half‐sibs and parents in selection scenarios for racing traits, for foal and racing traits, for studbook and racing traits, and using records of animal, half‐sibs and parents for foal traits and racing traits of parents. Racing time and earnings were the breeding objective. Low‐to‐moderate genetic correlations for body measurements and racing traits indicated that selection favours bigger horses at all ages. Being mainly favourable for the breeding objective, genetic correlations for conformation and functional traits with racing traits were highest for the foal traits of type, trot and overall grade and for the studbook traits of character and movements. Genetic correlations for foal and studbook conformation with racing traits were low in the Finnhorse and moderate to high in the Standardbred. In foals, the highest genetic correlations were for trot with racing time (?0.54) and with earnings (0.52) in the Finnhorse, and for overall grade with racing time (?0.54) and with earnings (0.54) in the Standardbred. In studbook horses, genetic correlations were high for character with racing time and earnings in the Finnhorse (?0.68, 0.61) and in the Standardbred (?0.63, 0.70), and for movements with racing time and earnings in the Finnhorse (?0.70, 0.69) and in the Standardbred (?0.90, 0.88). To increase accuracy of conformation and functional traits, foal traits would be more useful in the index with racing traits, as being less preselected than studbook traits. The foal traits (type, trot, overall grade) having moderate heritability and genetic correlations with racing traits would be useful in multi‐trait index before a racing career, where the greatest gain is because of a shorter generation interval. It would be feasible to implement for AI stallions.     

鲁西斗鸡体尺、体重及屠宰性状间的典型性相关分析

对鲁西斗鸡的体尺、体重和屠宰3组14个性状进行测定,并对这些变量进行了典型性相关分析。结果表明,体尺指标(胸深、胸宽、胫长、体斜长、龙骨长)间的相关系数为0.682~0.767;体重性状(初生重、180日龄重、日增重)间的相关系数为0.306~0.935,屠宰性能(胴体重、屠宰率、半净膛重、半净膛率、全净膛重,全净膛率)各项指标间高度相关,相关系数为0.945~0.986。体重性状和体尺性状间、体重性状与屠宰性状间及体尺性状与屠宰性状间的第一个典型相关系数差异极显著,其典型相关系数分别为0.705、0.560和0.878,贡献率分别为0.979、0.984和0.820。