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1.
China is abundant of sheep genetic resources. A total of 55 sequences containing the Ovis aries mtDNA D-loop of three large-fat-tailed sheep breeds, named Lanzhou, Tong, and Han were retrieved from GenBank to investigate their genetic diversity, origin, and phylogenetic evolution. The results showed that the sheep breeds in our study proved to be extremely diverse, the average haplotype diversity and nucleotide diversity were 0.987 ± 0.006 and 0.03956 ± 0.00206, respectively. The 55 sequences gave 39 different haplotypes. Phylogenetic analyses revealed that there were three distinct mtDNA haplogroups: A, B, and C, in which haplogroup A was predominant and had experienced population expansion events. Clustering analysis showed that the large-fat-tailed sheep breeds clustered into one group and were closely related to the Mongolian sheep and then European mouflon sheep (Ovis musimon). The results contribute to the knowledge of Chinese sheep breeds and the plan of conservation programs on large-fat-tailed sheep.  相似文献   

2.
Yunnan as a frontier zone that connects China with South and Southeast Asia, has 11 well‐recognized goat breeds. However, the knowledge about maternal origins, population structure and demographic history of Chinese indigenous goats from Yunnan is limited. In this study, we analysed a 481‐bp fragment of first hypervariable segment (HVSI) of the mitochondrial DNA (mtDNA) control region sequences of 749 individuals from 10 Yunnan indigenous goat breeds, of which 556 sequences were newly determined. There were 110 polymorphic sites that defined 158 haplotypes among all sequences. The haplotype and nucleotide diversity of these breeds ranged from 0.782 ± 0.079 to 0.982 ± 0.015 and from 0.028 ± 0.003 to 0.043 ± 0.005, respectively. Phylogenetic analysis identified two lineages A and B, of which the lineage A had higher frequency (68.1%) and distributed in all Yunnan breeds. We combined previously reported sequences with our sequences belonging to the lineage B and detected two subclades B1 and B2, in which the B1 subclade shared individuals from Eastern Asia, Southeast Asia and Southern Asia. Given higher level of diversity and more unique haplotypes, the B2 subclade probably originated from Southwestern China. The haplotype network, analysis of molecular variance (AMOVA) and a Mantel test revealed no significant phylogeographic structuring among Yunnan goat breeds. This can be explained by high gene flow and genetic admixture among these breeds from different geographic regions in Yunnan. Additionally, both the lineages A and B reflected different demographic histories. This study will provide a scientific basis for the conservation and utilization of Yunnan indigenous goats.  相似文献   

3.
The aim of this study was to characterize the genetic diversity of domestic goat in China. For this purpose, we determined the sequence of the mitochondrial DNA (mtDNA) control region in 72 individuals of the Yangtze River delta white goat, and reanalysed 723 published samples from 31 breeds/populations across China. All goat haplotypes were classified into four haplogroups (A–D) previously described. The phylogenetic pattern that emerged from the mtDNA control region sequence was confirmed by the analysis of the entire cytochrome b sequence of eight goats representative of the four haplogroups. It appeared that in Chinese domestic goat, haplogroups A and B were dominant and distributed in nearly all breeds/populations, while haplogroups C and D were only found in seven breeds/populations. Four breeds/populations contained all four haplogroups. When grouping the breeds/populations into five geographic groups based on their geographic distributions and ecological conditions, the southern pasturing area had the highest diversity whereas the northern farming area had the lowest diversity. 84.29% and 11.37% of the genetic variation were distributed within breeds and among breeds within the ecologically geographical areas, respectively; only 4% of genetic variation was observed among the five geographic areas. We speculate that the traditional seasonal pastoralism, the annual long-distance migrations that occurred in the past, and the commercial trade would account for the observed pattern by having favoured gene flows.  相似文献   

4.
A total of 135 unrelated sheep from nine Turkish native sheep breeds (Dagl?c, Kivircik, Imroz, Chios, Morkaraman, Ivesi, Hemsin, Karayaka and Akkaraman) were investigated to determinate the maternal genetic diversity using a sequence of a 531-bp segment of the mtDNA control region. Analysis of the mtDNA control region sequence revealed 63 haplotypes and 53 polymorphic sites. Haplotype diversity, nucleotide diversity and the average number of nucleotide differences were estimated to be 0.9496?±?0.011, 0.01407?±?0.00060 and 7.456, respectively. The sequence analysis also revealed high level of genetic diversity among the native Turkish breeds. These breeds were grouped into three major maternal haplogroups: A, B and C, with one animal belonging from the Akkaraman breed to the rare haplogroup E. Irregular shape of mismatch distribution of haplogroup C could be an indicator that haplogroup C may represent different haplogroups. Contrarily to previous studies carried out on Turkish native breeds, majority of animals grouped in haplogroup A in the present study. This result and the irregular shape of mismatch curve of haplogroup C indicate that genetic structure of Turkish native sheep breeds could be more complicated than it is thought.  相似文献   

5.
The origin of domestic horses in China was a controversial issue and several hypotheses including autochthonous domestication, introduction from other areas, and multiple‐origins from both introduction and local wild horse introgression have been proposed, but none of them have been fully supported by DNA data. In the present study, mitochondrial DNA (mtDNA) sequences of 714 Chinese indigenous horses were analyzed. The results showed that Chinese domestic horses harbor some novel mtDNA haplogroups and suggested that local domestication events may have occurred, but they are not the dominant haplogroups and the geographical distributions of the novel mtDNA haplogroups were rather restricted. Conclusively, our results support the hypothesis that the domestic horses in China originated from both the introduced horses from outside of China and the local wild horses' introgression into the domestic populations. Results of genetic diversity analysis suggested a possibility that the introduced horses entered China through northern regions from the Eurasian steppe.  相似文献   

6.
用12种限制性内切酶分析了6个地方绵羊品种线粒体DNA（mtDNA）细胞色素b（cytb）基因的RFLP。结果表明，在71只绵羊个体中，检出的14种限制性态型可归结成4种单倍型，其间的差异主要来源于几个限制性位点的点突变；4种单倍型间和6个绵羊群体间的平均遗传距离（D）分别为0．412％和0．041％，遗传多态程度（π）为0．028％，说明遗传多样性较为贫乏；单倍型聚类结果和群体聚类结果提示，我国地方绵羊品种的起源可能是单一的。  相似文献   

7.
为从分子水平上探究中国地方猪种遗传多样性和分类地位,本试验采用生物信息学方法比较了6个类型共22个中国地方猪种的线粒体基因组全序列,分析了其多态性,并构建了6个类型猪种线粒体D-loop区单倍型的网络中介图以及基于线粒体D-loop序列、Cytb基因、完整编码区序列的系统进化树。结果表明,6个类型22个猪种中共检测到了144个多态位点,22种单倍型,说明地方猪种具有丰富的遗传多样性;地方猪线粒体基因组序列中核苷酸变异以转换为主,且Ti/Tv大于转换/颠换比临界值（2.0）,变异位点均符合中性突变。6个类型猪种间遗传距离均较小,且有共享单倍型。系统进化树结果表明,6种类型地方猪种主要聚为两个支系。表明线粒体D-loop序列及Cytb基因均可作为研究种内系统发育、起源进化的分子标记。  相似文献   

8.
In order to explore the genetic diversity and the classification status of the Chinese domestic pigs at the molecular level, the complete mitochondrial DNA (mtDNA) genomic sequences of 22 Chinese indigenous pig breeds from 6 types were downloaded from GenBank for the analysis using the bioinformatics method. The polymorphism of nucleic acid sequences was analyzed,the molecular phylogenetic tree based on D-loop sequences, Cytb gene, complete coding region mtDNA sequences and the Median-Joining network of the mtDNA D-loop haplotypes were constructed for 22 pig breeds from 6 types. The results showed that a total of 144 mutation sites among 22 pig breeds were detected, 22 haplotypes were discovered, which indicated that Chinese indigenous pig breeds had abundant genetic diversity. According to the complete mtDNA genomic sequences analysis, which suggested that the main mutations was transition, the transition/transversion ratio was greater than 2.0 and all mutations were in line with the neutral mutation. Our findings clearly demonstrated that there was a near genetic distance among 6 types, meanwhile, the shared haplotypes were found. The phylogenetic tree showed that Chinese indigenous pigs from 6 types were diverged from two ancestors.The results indicated that mtDNA D-loop and Cytb gene might serve as molecular markers for phylogenesis, origin and evolution.  相似文献   

9.

Ethiopia is home to a diverse gene pool of indigenous sheep populations. Therefore, a better understanding of genetic variation holds the key to future utilization through conservation. Three of these breeds, Afar, Blackhead Somali, and Hararghe Highland, are found in eastern Ethiopia where they contribute significantly to the livelihood of most pastoralist, agro-pastoralist, and smallholder farmers. These indigenous sheep are recognized on the basis of morphotype and their genetic distinction remains unknown. Here, to assess genetic variation, and matrilineal genetic origin and relationship of fat-rumed sheep found in eastern Ethiopia, 300 individuals from the three breeds were genotyped for 22 microsatellite markers and sequenced for the mitochondrial DNA displacement loop (mtDNA d-loop) region. The overall HO and HE were 0.57 and 0.75, respectively. Differentiation statistics revealed that a high proportion (97%) of the total genetic variation was explained by differences between individuals within populations. Genotype assignment independent of the population of origin showed K?=?2 to be the optimum number of genetic backgrounds present in the dataset. This result was further confirmed by mtDNA D-loop sequences comparison in which the matrilineal genetic origin of eastern Ethiopia sheep is from two haplotype groups (types A and B) among the five haplotypes globally observed. Taken together, our findings suggest that the sheep populations from three breeds originated from two ancestral genetic backgrounds that may have diverged prior to their introduction to Ethiopia. However, to obtain a complete picture of the evolutionary dynamics of Ethiopian indigenous sheep, more samples and populations from within and outside of the country will need to be analyzed.

  相似文献   

10.
1. To explore the genetic diversity of Chinese indigenous chicken breeds, a 585 bp fragment of the mitochondrial DNA (mtDNA) region was sequenced in 102 birds from the Xichuan black-bone chicken, Yunyang black-bone chicken and Lushi chicken. In addition, 30 mtDNA D-loop sequences of Silkie fowls were downloaded from NCBI. The mtDNA D-loop sequence polymorphism and maternal origin of 4 chicken breeds were analysed in this study.

2. The results showed that a total of 33 mutation sites and 28 haplotypes were detected in the 4 chicken breeds. The haplotype diversity and nucleotide diversity of these 4 native breeds were 0.916 ± 0.014 and 0.012 ± 0.002, respectively. Three clusters were formed in 4 Chinese native chickens and 12 reference breeds. Both the Xichuan black-bone chicken and Yunyang black-bone chicken were grouped into one cluster. Four haplogroups (A, B, C and E) emerged in the median-joining network in these breeds.

3. It was concluded that these 4 Chinese chicken breeds had high genetic diversity. The phylogenetic tree and median network profiles showed that Chinese native chickens and its neighbouring countries had at least two maternal origins, one from Yunnan, China and another from Southeast Asia or its surrounding area.  相似文献   


11.
采用PCR—SSCP技术及mtDNA D-loop序列分析相结合的方法，对我国云南昭通绵羊、腾冲绵羊、宁蒗绵羊及西藏的多玛绵羊、江孜绵羊5个地方绵羊群体共232个个体进行遗传多样性及系统进化分析。PCR-SSCP分析显示，在西藏的多玛绵羊和江孜绵羊中均检测到线粒体编码区的Cytb和ND2基因的3种单倍型A、B和C，且在西藏的多玛绵羊、江孜绵羊中C单倍型比例高于B型；而在云南的昭通绵羊、腾冲绵羊和宁蒗绵羊中只检测到单倍型A和B。根据不同的单倍型从5个群体中筛选出39个样品进行mtDNAD-loop区克隆测序，经过系统进化分析揭示西藏绵羊存在A、B、C3种mtDNA单倍型；而云南绵羊只存在A、B2种mtDNA单倍型。以上基于PCR-SSCP和D-loop区序列的分析结果一致提示西藏绵羊有3个母系来源，云南绵羊有2个母系来源。基于mtDNAD-loop序列的多态性分析结果显示西藏多玛绵羊和江孜绵羊的单倍型多样度（Hd）、核苷酸多样度（Pi）及平均核苷酸差异数（k）均高于云南3个地方绵羊品种，提示西藏绵羊遗传多样性较丰富，云南绵羊遗传多样性相对贫乏。  相似文献   

12.
China is one of the most diverse countries, which have developed 88 indigenous pig breeds. Several studies showed that pigs were independently domesticated in multiple regions of the world. The purpose of this study was to investigate the origin and evolution of Chinese pigs using complete mitochondrial genomic sequences (mtDNA) from Asian and European domestic pigs and wild boars. Thirty primer pairs were designed to determine the mtDNA sequences of Xiang pig, Large White, Lantang, Jinhua and Pietrain. The phylogenetic status of Chinese native pigs was investigated by comparing the mtDNA sequences of complete coding regions and D-loop regions respectively amongst Asian breeds, European breeds and wild boars. The analyzed results by two cluster methods contributed to the same conclusion that all pigs were classified into two major groups, European clade and Asian clade. It revealed that Chinese pigs were only recently diverged from each other and distinctly different from European pigs. Berkshire was clustered with Asian pigs and Chinese pigs were involved in the development of Berkshire breeding. The Malaysian wild boar had distant genetic relationship with European and Asian pigs. Jinhua and Lanyu pigs had more nucleotide diversity with Chinese pigs although they all belonged to the Asian major clade. Chinese domestic pigs were clustered with wild boars in Yangtze River region and South China.  相似文献   

13.
Myanmar indigenous chickens play important roles in food, entertainment, and farm business for the people of Myanmar. In this study, complete mitochondrial D-loop sequences (1232 bp) were analyzed using 176 chickens, including three indigenous breeds, two fighting cock populations, and three indigenous populations to elucidate genetic diversity and accomplish a phylogenetic analysis of Myanmar indigenous chickens. The average haplotype and nucleotide diversities were 0.948 ± 0.009 and 0.00814 ± 0.00024, respectively, exhibiting high genetic diversity of Myanmar indigenous chickens. Sixty-four haplotypes were classified as seven haplogroups, with the majority being haplogroup F. The breeds and populations except Inbinwa had multiple maternal haplogroups, suggesting that they experienced no recent purifying selection and bottleneck events. All breeds and populations examined shared haplogroup F. When 232 sequences belonging to haplogroup F (79 from Myanmar and 153 deposited sequences from other Asian countries/region) were analyzed together, the highest genetic diversity was observed in Myanmar indigenous chickens. Furthermore, Myanmar indigenous chickens and red junglefowls were observed in the center of the star-like median-joining network of 37 F-haplotypes, suggesting that Myanmar is one of the origins of haplogroup F. These findings revealed the unique genetic characteristic of Myanmar indigenous chickens as important genetic resources.  相似文献   

14.
我国主要地方绵羊品种遗传亲缘关系   总被引：12，自引：0，他引：12  
利用 10种 10碱基的随机引物 ,分析了我国 8个地方绵羊品种计 88只绵羊的随机扩增多态 DNA。结果表明 ,我国地方绵羊品种基因组 DNA多态位点百分率为 81.36 % ,群体平均遗传多样性指数为 1.3370 ,具有丰富的群体遗传多样性。但滩羊、小尾寒羊、藏绵羊和蒙古羊群体遗传多样性程度较低 ,应加强保种措施。群体遗传分化指数为0 .9172 ,说明遗传变异主要存在于群体间。品种间的分子聚类关系基本上反映了品种间的遗传亲缘关系 ,与品种的形成历史及我国地方绵羊的起源进化学说基本一致 ,具有相同来源的蒙古羊、乌珠穆沁羊、小尾寒羊和湖羊的分子聚类关系表明 ,4个地方绵羊品种间已经有了明显的遗传分化 ,小尾寒羊、乌珠穆沁羊间遗传分化较低 ,湖羊与蒙古羊之间相对较高 ,而小尾寒羊和乌珠穆沁羊与湖羊和蒙古羊之间的遗传分化最高  相似文献   

15.
本研究旨在了解酪氨酸酶相关蛋白1（tyrosinase related protein 1，TYRP1）基因在中国地方绵羊群体内的遗传变异，以及TYRP1基因突变与不同毛色表型绵羊群体的相关性。通过直接测序法和PCR-RFLP技术对10个中国地方绵羊群体进行单核苷酸多态性（SNP）检测，利用Beagle、PLINK和POPGENE等软件对突变位点数据进行单倍型构建、连锁不平衡分析和遗传变异研究。突变位点检测结果表明，在绵羊TYRP1基因内识别了13个SNPs，其中位于TYRP1基因外显子上的10个SNPs位点，除个别位点在大尾寒羊、中国美利奴羊和岷县黑裘皮羊中没有发生突变外，其他突变位点在所有绵羊品种中均出现不同程度变异，说明中国地方绵羊群体具有较高的遗传多样性。单倍型分析结果表明，所有样本中共有42个单倍型，优势单倍型0000000000（245/918）、0100000001（91/918）在所有绵羊群体中均存在，除单倍型0101100000（93/918）在中国美利奴羊中没有出现，单倍型0001000001（69/918）在岷县黑裘皮羊、哈萨克羊群体中没有出现外，在其他群体中均存在。连锁分析结果表明，10个SNPs在所有样本中均存在2个连锁模块。群体遗传变异分析表明，中国地方绵羊群体具有较高水平的群体内遗传变异，各绵羊品种间存在明显的遗传分化模式，且各品种遗传关系与其品种传统分类结果基本一致。本研究为进一步研究TYRP1基因对绵羊毛色遗传性状的影响提供了参考依据。  相似文献   

16.
As the fast pace of genomic research continues to identify mitochondrial lineages in animals, it has become apparent that many independent studies are needed to support a robust phylogenetic inference. The aim of this study was thus to further characterize the maternal lineage, proposed to originate in southwestern region of China, using a wider survey of diverse goat breeds in China. To this end, we sequenced the mitochondrial hypervariable region 1 (HVR1) of the mtDNA control region in 145 goats of 12 Chinese breeds. Phylogenetic analysis revealed that Chinese goats were classified into four distinct lineages (A, B, C and D) as previously reported. A Mantel test and the analysis of Analysis of Molecular Variance (ANOVA) indicated that there was not an obvious geographic structure among Chinese goat breeds. Population expansion analysis based on mismatch distribution and Fu's Fs statistic indicate that two expansion events in Chinese goats occurred respectively at about 11 and 29 mutational time units ago, revealing two star-like subclades in lineage B corresponding to two population expansion events. Moreover, lineage B sequences were presented only in the breeds of southwestern or surrounding regions of China. Multiple lines of evidence from this study and previous studies indicate that for Chinese goats mtDNA lineage B originated from the southwestern region of China.  相似文献   

17.
To understand the origin and genetic phylogeography of Chinese black goats, variations of mitochondrial DNA were characterised with 394 goats from 18 breeds, including 91 new individuals from regions poorly studied until now. Comparison of a 481-bp segment revealed a total of 192 haplotypes with 141 variable sites. The haplotype and nucleotide diversities ranged from 0.782?±?0.079 to 1.000?±?0.020 and from 0.009?±?0.001 to 0.045?±?0.006, respectively, indicating a relatively high genetic diversity in Chinese black goats. Phylogenetic analyses identified five haplogroups (A, B1, B2, C and D). The dominant haplogroups A, B1 and B2 were distributed in most of breeds, while the haplogroups C and D were only presented in the breeds located in north or northwest of China. Analysis of molecular variance and multidimensional scaling plot of F ST analyses indicated no obvious geographic structure among breeds. Furthermore, the migration rates revealed that a wide range of gene flow or gene exchange occurred among breeds, which may result in the weak geographic structure of Chinese black goats. Population expansion analysis based on mismatch distribution indicated that two expansion events in Chinese black goats occurred at 10 and 28 mutational time units. Finally, our findings indicate the multiple maternal origins of Chinese black goats and more gene flow (female-mediated) which occurred during their domestic and breeding histories.  相似文献   

18.
Eighteen microsatellites were used to investigate the genetic diversity and differentiation of eight Chinese indigenous goat breeds. The results indicated that there is a significant difference of genetic diversity between different loci. Chinese indigenous goat breeds have similar genetic diversity to other Asian goats, but with lower Fst. The clustering of individuals and populations showed that Chinese indigenous goat breeds might have originated from two ancestral populations. The genetic differentiation between populations is consistent with the results of archaeology, mtDNA and RAPD.  相似文献   

19.
Spermatogenesis in bulls (Bos indicus) indigenous to Nigeria, and the significance of Sertoli cell index (SCI) as a measure of testicular degeneration were studied. The mean testicular weights and dimensions were lower than reported forBos taurus breeds. The diameters of the seminiferous tubules were lower than reported forBos taurus, although within the same range. Inter-month and intra-month variations were highly significant (P<0.01). A mean annual spermatogenesis of 77.60% was reported. Active spermatogenesis was observed throughout the year, with a peak during the rainy season and extending toward the predry season. This was consistent with previous reports. Severe testicular degeneration was found to influence spermatogenesis. This was reflected in the decrease in SCI. Mild degeneration had no significant effect on spermatogenesis, and did not significantly change the SCI. The SCI was defined as the ratio of the number of germinal cells to the number of Sertoli cells in the same cross sections of tubules.  相似文献   

20.
Phylogenetic relationships among and genetic variability within 60 goats from two different indigenous breeds in Narok and Isiolo counties in Kenya and 22 published goat samples were analysed using mitochondrial control region sequences. The results showed that there were 54 polymorphic sites in a 481‐bp sequence and 29 haplotypes were determined. The mean haplotype diversity and nucleotide diversity were 0.981 ± 0.006 and 0.019 ± 0.001, respectively. The phylogenetic analysis in combination with goat haplogroup reference sequences from GenBank showed that all goat sequences were clustered into two haplogroups (A and G), of which haplogroup A was the commonest in the two populations. A very high percentage (99.90%) of the genetic variation was distributed within the regions, and a smaller percentage (0.10%) distributed among regions as revealed by the analysis of molecular variance (amova ). This amova results showed that the divergence between regions was not statistically significant. We concluded that the high levels of intrapopulation diversity in Isiolo and Narok goats and the weak phylogeographic structuring suggested that there existed strong gene flow among goat populations probably caused by extensive transportation of goats in history.  相似文献   

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