家养动物的起源与驯化研究进展

动物的驯化是新石器时代农业革命的主要内容之一, 导致了人类生活方式从狩猎向畜牧的转变。开展家养动物起源与驯化的研究, 不仅有助于了解人类社会的发展史和人工选择下动物的进化过程, 而且有助于开展家养动物的良种选育和遗传多样性保护, 因此该研究领域受到了人们的长期关注。近年来, 随着更多考古证据的发现与分子遗传学的发展, 人们对于家养动物的起源与驯化有了更深入的认识。本文对家养动物起源与驯化研究中一些基本问题的研究方法和进展进行了综述。文章第一部分介绍了家养动物的野生祖先、起源地、起源时间、建群者大小和扩散路线等问题; 第二部分则涉及家养动物驯化的条件、过程、性状改变及其遗传机制等方面。最后指出了家养动物起源与驯化研究中依然存在的问题, 并对未来研究发展的趋势进行了讨论。     

设施黄瓜育成品种果实外观品质的遗传多样性分析

对我国新育成的不同生态类型的138个设施黄瓜品种的19个果实外观性状进行了调查分析,研究其遗传多样性。结果表明,参试品种质量性状的遗传多样性指数都小于数量性状,不同生态类型黄瓜品种果实外观性状的遗传多样性指数为华北型(1.33)>华南型(1.25)>欧洲温室型(1.0)。质量性状的遗传多样性指数为华南型(0.91)>华北型(0.65)>欧洲温室型(0.48);数量性状的遗传多样性指数为华北型(1.94)>华南型(1.56)>欧洲温室型(1.47)。华南型品种果实数量性状的变异系数均高于华北型和欧洲温室型品种。主坐标轴分析(PCO)将所有种质划分为3个区组,即1区为华北型种质优势区、2区为华北型华南型和欧洲温室型种质混合分布区、3区为华南型种质区。PCO结果表明,1区和2区发生了基因渗透。对交流区域中华北型品种自交分离,后代中出现的稀刺瘤和光皮种质的情况进一步验证了基因渗透的结果。参照育成品种的果实性状信息对黄瓜以后的育种工作提出了建议。     

本土绵羊品种GH与IGF-1基因多态性分析

生长性状是绵羊育种中关注的重要性状.GH和IGF-1基因已被证明是影响动物生长发育的重要候选基因.因此,了解中国本土绵羊GH和IGF-1基因的遗传多样性,将为提高本土绵羊的生产效率、制定遗传育种和品种改良措施奠定基础.本研究以本土绵羊品种呼伦贝尔羊、藏羊、湖羊、阿勒泰羊、小尾寒羊和滩羊为主要研究对象,以澳白羊为参考,通...     

SNaPshot技术检测滩羊双羔群体中与多胎性状相关SNP研究

对我国地方品种滩羊双羔群体进行SNP检测和多胎性状相关性研究,促进SNPs在双羔家系分子育种中的应用。从实验前期SNP筛选的基础上,利用候选基因飞行质谱法最终确定3种基因13个SNP位点作为候选位点,对滩羊双羔群体的多胎位点进行多态性检测,分析群体差异性,筛选多羔候选基因。关联分析表明:13个位点中有5个位点与多胎性能有关,3种遗传模型也被证实,但BMPR1B基因构建的单倍型却与多胎性能无关。本研究旨在为滩羊双羔分子标记本品种选种选配等分子辅助育种技术提供参考,保护与可持续利用地方家养动物稀有种质遗传资源,加快优质多胎肉羊的发展。     

甘、青两省春小麦遗传多样性演变

对甘、青两省自20世纪40年代以来生产上曾大面积应用的200多个春小麦地方品种和育成品种资料进行了分析,结果表明,19个形态性状,5个农艺性状和2个品质性状都存在着广泛的遗传多样性,虽然育成品种农艺性状和品质性状的遗传多样性总体上大于地方品种,但是从20世纪60年代开展春小麦杂交育种工作之后,育成品种形态性状,农艺性状和品质性状遗传多样性呈下降趋势,评价育种对小麦遗传多样性的影响,不能足将地方品种和育成品种的遗传多样性作一简单比较就得出结论,而是应该在遗传多样性演变的动态过程中去研究。     

家养动物驯化起源的研究方法与进展

驯化动物伴随了人类上万年的进化历程。在驯化过程中, 家养动物表型和行为特征发生巨大改变, 并与人类生产生活的进步相适应。研究动物驯化问题对于了解遗传多样性及适应性进化, 解析复杂性状的遗传机制等具有重要的意义, 成为生物学领域的重点研究内容之一。本文专注于动物驯化的初始阶段, 首先介绍了驯化起源的时间与地点、驯化途径和驱动因、驯化后的扩散和品种选育; 其次从驯化对象的角度着重介绍了考古学、分子和群体遗传学两方面的家养动物驯化起源的研究策略、优势与不足, 以及未来的发展方向; 最后, 我们综合多方面的证据, 介绍了在中国驯化的家猪(Sus domesticus)和家鸡(Gallus gallus domesticus)以及其他主要家养动物考古和分子水平上驯化起源的研究进展。本文整合多种证据为家养动物驯化起源的研究提供了相对完整的视角和新的思路。     

DNA分子标记技术及其在水产动物遗传上的应用研究

随着DNA分子标记技术的发展,其在动物遗传上发挥了重大作用,使用DNA分子标记可以观察到整个基因组的遗传多样性。目前,在水产养殖种类中使用的遗传标记主要包括线粒体DNA、RFLP、RAPD、AFLP、微卫星、SNP和EST标记。DNA分子标记的应用使得人们对水产养殖动物的遗传多样性、近亲繁殖、种类和品系鉴定以及遗传连锁图谱建立的研究都取得了很大进展,也加快了数量性状位点(QTL)基因的鉴定作为分子标记辅助选择(MAS)的研究。将这些标记技术在水产动物上的应用进行了论述,以及如何从人类基因组工程和斑马鱼这种模式鱼的研究中得到启发,更好的应用于水产动物基因组学和遗传学研究做一讨论。     

浙江省薄皮甜瓜地方品种的表型遗传多样性

利用表型性状探讨了浙江省沿海地区27份薄皮甜瓜地方品种资源的遗传多样性。结果表明48个质量性状遗传多样性指数在0.17–1.98之间;33个数量性状的变异系数在4.56%–83.50%,表明其丰富的遗传多样性。形态学聚类分析表明,在相似系数0.30处可以将27个资源分成两大类,这与按生育期长短分类结果完全一致;亚类的划分与果实形状、种子形状、叶片颜色、果皮颜色、覆纹颜色等质量性状具有一定的相关性,但其划分依据相对独立。本研究结果进一步丰富了甜瓜的评价体系,并为今后优异基因资源的挖掘与利用提供重要依据。     

浙江省沿海地区南瓜地方品种的表型遗传多样性

利用表型性状探讨了浙江省沿海地区20份南瓜地方品种资源的遗传多样性。结果表明,36个数量性状的变异系数在7.33%~59.11%之间,46个质量性状Shannon-wiener遗传多样性指数在0~1.99之间,表明其丰富的遗传多样性。农艺性状聚类分析表明,20份资源分为2大类,其中19份资源归为一大类;在欧氏距离15.0处把这一大类又分成5个小类,小类的划分与花萼片大小、花梗刺毛、瓜形、老瓜皮色等质量性状具有一定的相关性,但划分依据相对独立。本研究结果进一步丰富了南瓜的评价体系,并为今后优异基因资源的挖掘与利用提供了重要依据。     

小粒野生稻优异基因的挖掘与利用研究进展

小粒野生稻拥有丰富的遗传多样性,含有大量的优异基因,是进行栽培稻遗传改良和基因组研究的宝贵资源。本文总结了国内外研究利用小粒野生稻种质取得的系列进展,主要包括:小粒野生稻优异性状的鉴定和遗传群体的构建,小粒野生稻有利基因的定位、克隆与育种利用,还对小粒野生稻优异基因利用的困难和应对策略进行了讨论。这些结果必将有利于进一步挖掘和利用小粒野生稻的有利基因。     

Utilization of DNA marker-assisted selection in Korean native animals

The recent progress of DNA technologies including DNA fingerprinting (DFP) and random amplified DNA polymorphism (RAPD) analysis make it possible to identify the specific genetic traits of animals and to analyze the genetic diversity and relatedness between or within species or populations. Using those techniques, some efforts to identify and develop the specific DNA markers based on DNA polymorphism, which are related with economic traits for Korean native animals, Hanwoo (Korean native cattle), Korean native pig and Korean native chicken, have been made in Korea for recent a few years. The developed specific DNA markers successfully characterize the Korean native animals as the unique Korean genetic sources, distinctively from other imported breeds. Some of these DNA markers have been related to some important economic traits for domestic animals, for example, growth rate and marbling for Hanwoo, growth rate and back fat thickness for native pig, and growth rate, egg weight and egg productivity for native chicken. This means that those markers can be used in important marker-assisted selection (MAS) of Korean native domestic animals and further contribute to genetically improve and breed them.     

Molecular identification of livestock breeds: a tool for modern conservation biology

Global livestock genetic diversity includes all of the species, breeds and strains of domestic animals, and their variations. Although a recent census indicated that there were 40 species and over 8000 breeds of domestic animals; for the purpose of conservation biology the diversity between and within breeds rather than species is regarded to be of crucial importance. This domestic animal genetic diversity has developed through three main evolutionary events, from speciation (about 3 million years ago) through domestication (about 12000 years ago) to specialised breeding (starting about 200 years ago). These events and their impacts on global animal genetic resources have been well documented in the literature. The key importance of global domestic animal resources in terms of economic, scientific and cultural heritage has also been addressed. In spite of their importance, there is a growing number of reports on the alarming erosion of domestic animal genetic resources. This erosion of is happening in spite of several global conservation initiatives designed to mitigate it. Herein we discuss these conservation interventions and highlight their strengths and weaknesses. However, pivotal to the success of these conservation initiatives is the reliability of the genetic assignment of individual members to a target breed. Finally, we discuss the prospect of using improved breed identification methodologies to develop a reliable breed‐specific molecular identification tool that is easily applicable to populations of livestock breeds in various ecosystems. These identification tools, when developed, will not only facilitate the regular monitoring of threatened or endangered breed populations, but also enhance the development of more efficient and sustainable livestock production systems.     

福建家鸭品种的分子遗传多样性

通过筛选的28个多态性较好的微卫星标记检测了福建省金定鸭、莆田黑鸭、连城白鸭、山麻鸭4个家鸭品种的遗传多样性.利用等位基因频率计算了各群体的遗传参数、群体间的Nei氏标准遗传距离D_S和D_A遗传距离,并采用邻近法（NJ）和类平均法（UPGMA）进行聚类分析和比较.结果表明,福建省4个家鸭品种全部群体的平均杂合度为0.5353,遗传一致性较好,应加强各保种场（区）多样性的保护;各品种间的遗传距离远近顺序在两种遗传距离D_S和D_A的结果中完全一致,以D_A和D_S为基础分别得到的UPGMA和NJ的聚类结果完全相同,表明在应用微卫星标记分析品种的遗传多样性时,使用更多的微卫星位点,才可以获得更准确更具普遍性的结论.4个家鸭品种的聚类与各品种的经济类型、生态地域分布关系密切.     

Levels and Patterns of Genetic Diversity and Population Structure in Domestic Rabbits

Over thousands of years humans changed the genetic and phenotypic composition of several organisms and in the process transformed wild species into domesticated forms. From this close association, domestic animals emerged as important models in biomedical and fundamental research, in addition to their intrinsic economical and cultural value. The domestic rabbit is no exception but few studies have investigated the impact of domestication on its genetic variability. In order to study patterns of genetic structure in domestic rabbits and to quantify the genetic diversity lost with the domestication process, we genotyped 45 microsatellites for 471 individuals belonging to 16 breeds and 13 wild localities. We found that both the initial domestication and the subsequent process of breed formation, when averaged across breeds, culminated in losses of ~20% of genetic diversity present in the ancestral wild population and domestic rabbits as a whole, respectively. Despite the short time elapsed since breed diversification we uncovered a well-defined structure in domestic rabbits where the F_ST between breeds was 22%. However, we failed to detect deeper levels of structure, probably consequence of a recent and single geographic origin of domestication together with a non-bifurcating process of breed formation, which were often derived from crosses between two or more breeds. Finally, we found evidence for intrabreed stratification that is associated with demographic and selective causes such as formation of strains, colour morphs within the same breed, or country/breeder of origin. These additional layers of population structure within breeds should be taken into account in future mapping studies.     

Localization of Canine Brachycephaly Using an Across Breed Mapping Approach

The domestic dog, Canis familiaris, exhibits profound phenotypic diversity and is an ideal model organism for the genetic dissection of simple and complex traits. However, some of the most interesting phenotypes are fixed in particular breeds and are therefore less tractable to genetic analysis using classical segregation-based mapping approaches. We implemented an across breed mapping approach using a moderately dense SNP array, a low number of animals and breeds carefully selected for the phenotypes of interest to identify genetic variants responsible for breed-defining characteristics. Using a modest number of affected (10–30) and control (20–60) samples from multiple breeds, the correct chromosomal assignment was identified in a proof of concept experiment using three previously defined loci; hyperuricosuria, white spotting and chondrodysplasia. Genome-wide association was performed in a similar manner for one of the most striking morphological traits in dogs: brachycephalic head type. Although candidate gene approaches based on comparable phenotypes in mice and humans have been utilized for this trait, the causative gene has remained elusive using this method. Samples from nine affected breeds and thirteen control breeds identified strong genome-wide associations for brachycephalic head type on Cfa 1. Two independent datasets identified the same genomic region. Levels of relative heterozygosity in the associated region indicate that it has been subjected to a selective sweep, consistent with it being a breed defining morphological characteristic. Genotyping additional dogs in the region confirmed the association. To date, the genetic structure of dog breeds has primarily been exploited for genome wide association for segregating traits. These results demonstrate that non-segregating traits under strong selection are equally tractable to genetic analysis using small sample numbers.     

The genetic contribution to canine personality

The domestic dog may be exceptionally well suited for behavioral genetic studies owing to its population history and the striking behavior differences among breeds. To explore to what extent and how behavioral traits are transmitted between generations, heritabilities and genetic correlations for behavioral traits were estimated in a cohort containing over 10,000 behaviorally tested German shepherd and Rottweiler dogs. In both breeds, the pattern of co-inheritance was found to be similar for the 16 examined behavioral traits. Furthermore, over 50% of the additive genetic variation of the behavioral traits could be explained by one underlying principal component, indicating a shared genetic component behind most of the examined behavioral traits. Only aggression appears to be inherited independently of the other traits. The results support a genetic basis for a broad personality trait previously named shyness-boldness dimension, and heritability was estimated to be 0.25 in the two breeds. Therefore, breeds of dogs appear to constitute a valuable resource for behavioral genetic research on the normal behavioral differences in broad personality traits.     

Mitochondrial DNA diversity and origins of domestic goats in Southwest China (excluding Tibet)

Southwest China contains about one third Chinese indigenous goat breeds representing special economic and ecological characteristics. Mitochondrial DNA (mtDNA) D-loop sequences of 312 individuals (including 109 new individuals, 203 individuals retrieved from GenBank) from 18 Chinese domestic goat breeds were used to investigate breed genetic diversity, origin and phylogeography. All goat breeds in this study proved to be extremely diverse, average haplotype diversity and nucleotide diversity being 0.9829 ± 0.0027 and 0.03615 ± 0.03257, respectively. The 312 sequences gave 148 different haplotypes. Phylogenetic analyses revealed that there were two mtDNA haplogroups identified in domestic goats in Southwest China, in which haplogroup A was predominant. Mismatch analysis showed haplogroup A had experienced population expansion events, whereas haplogroup B did not. Amova analysis showed there was no significant geographical structuring. Almost 86.23% of genetic variation was included in the within-breed variance component and only 3.5% was observed among the four geographic provinces. The results of this study contribute to the knowledge of the genetic structure and origin of domestic goats in Southwest China.     

Chicken domestication: from archeology to genomics

Current knowledge on chicken domestication is reviewed on the basis of archaeological, historical and molecular data. Several domestication centres have been identified in South and South-East Asia. Gallus?gallus is the major ancestor species, but Gallus?sonneratii has also contributed to the genetic make-up of the domestic chicken. Genetic diversity is now distributed among traditional populations, standardized breeds and highly selected lines. Knowing the genome sequence has accelerated the identification of causal mutations determining major morphological differences between wild Gallus and domestic breeds. Comparative genome resequencing between Gallus and domestic chickens has identified 21 selective sweeps, one involving a non-synonymous mutation in the TSHR gene, which functional consequences remain to be explored. The resequencing approach could also identify candidate genes responsible of quantitative traits loci (QTL) effects in selected lines. Genomics is opening new ways to understand major switches that took place during domestication and subsequent selection.     

Genetic relationships between Japanese native and commercial breeds using 70 chicken autosomal SNP genotypes by the DigiTag2 assay

Recently, single nucleotide polymorphisms (SNPs) have been used to identify genes or genomic regions responsible for economic traits, including genetic diseases in domestic animals, and to examine genetic diversity of populations. In this study, we genotyped 70 chicken autosomal SNPs using DigiTag2 assay to understand the genetic structure of the Japanese native chicken breeds Satsumadori and Ingie, and the relationship of these breeds with other established breeds, Rhode Island Red (RIR), commercial broiler and layer. Five breeds, each consisting of approximately 20 chickens, were subjected to the assay, revealing the following: Average expected heterozygosities of broiler, Satsumadori, RIR, layer and Ingie were 0.265, 0.254, 0.244, 0.179 and 0.176, respectively. Phylogenetic analysis using the concatenated 70 autosomal SNP genotypes distinguished all chickens and formed clusters of chickens belonging to the respective breeds. In addition, the 2-D scatter plot of the first two principal components was consistent with the phylogenic tree. Taken together with the pairwise F(st) distances, broiler and RIR were closely positioned near each other, while Ingie was positioned far from the other breeds. Structure analysis revealed that the probable number of genetic clusters (K) was six and four with maximum likelihood and ΔK values, respectively. The clustering with maximum likelihood revealed that, in addition to the clustering of the other five breeds, the Satsumadori was subdivided into two genetic clusters. The clustering with ΔK value indicated that the broiler and Rhode Island Red were assigned to the same genetic cluster.     

中国绵羊起源、进化和遗传多样性研究进展

中国地方绵羊品种资源丰富,部分品种具有繁殖力高、毛皮品质好、多角、多乳头、大尾脂、抗逆性强等独特性状,这些遗传资源引起了学者们对其进行深入研究的兴趣,但目前仍然存在绵羊起源问题的争议,缺乏对我国绵羊的遗传多样性进行全面系统研究等问题。本文综述了绵羊起源、品种分化等方面的研究进展,并从父系、母系、常染色体分子标记等不同层面介绍了中国绵羊遗传多样性的研究概况,为中国绵羊遗传资源的保护和利用、绵羊新品种(系)的培育以及我国绵羊产业良性发展提供参考。