RESUMEN
With the rapid development of high-throughput SNP array and significant reduction of sequencing cost, the techniques of genome-resequencing and SNP chip arrays are widely applied in livestock genomic studies. Long runs of homozygosity (ROH) arose when identical haplotypes were inherited from each parent and thus a long tract of genotypes is homozygous. Nowadays, cumulative studies reported that ROH has progressively served as one of the important indexes to estimate the degree of inbreeding and genetic structure of livestock populations. However, the evaluating criteria of ROH in livestock is still inadequate. In this review, we introduce the history, theory and identification methods of ROH analysis. Meanwhile, we also systematically overview the applications and perspectives of ROH in population genetic structure analysis, genome functional assay, quality investigation and dynamic monitoring of livestock genetic resources.
Asunto(s)
Homocigoto , Endogamia , Ganado/genética , Polimorfismo de Nucleótido Simple , Animales , GenomaRESUMEN
The genetic variations and polymorphisms of six microsatellite loci were analyzed to determine the population structure and breeding progress of BMY and Brahman cattle. The range of polymorphic information content of six loci was 0.524-0.752. The unbiased expected and observed heterozygosity were similar and were 0.7376 and 0.7396, 0.6412 and 0.6537 for BMY and Brahman cattle, respectively. The expected heterozygosity was relatively high in the second generation of BMY in inter se breeding, which was congruent with the breeding progress. In addition, the value for Red Angus was 0.4609, which was lower and close to the Japanese Brown cattle (0.471), and may indicate its relative homogeneity.
Asunto(s)
Variación Genética/genética , Repeticiones de Microsatélite/genética , Animales , Bovinos , Genética de Población , Heterocigoto , Polimorfismo Genético/genéticaRESUMEN
In this study, random amplified polymorphic DNA (RAPD) analysis was used to estimate genetic diversity and relationship in 134 samples belonging to two native cattle breeds from the Yunnan province of China (DeHong cattle and DiQing cattle) and four introduced beef cattle breeds (Brahman, Simmental, MurryGrey, and ShortHorn). Ten primers were used, and a total of 84 bands were scored, of which 63 bands (75.0%) were polymorphic. The genetic distance matrix was obtained by proportions of shared fragment. The results indicate that the Yunnnan DeHong cattle breed is closely related to the Brahman (Bos indicus), and the Yunnan DiQing cattle breed is closely related to the Simmental, ShortHorn, and MurryGrey (Bos taurus) breeds. Our results imply that Bos indicus and Bos taurus were the two main origins of Yunnan native cattle. The results also provide the basic genetic materials for conservation of cattle resources and crossbreeding of beef cattle breeds in South China.
