实验用巴马小型猪的遗传多样性研究

Study on the genetic diversity of experimental Bama miniature pigs

为了研究屏障环境下小规模保存实验用巴马小型猪的遗传学背景,试验运用19个微卫星基因座,对长期在屏障环境下封闭饲养的同世代、同父本但不同母本的3窝巴马小型猪(BM/HVRI猪)进行分子群体遗传学检测,计算平均等位基因数(Na)、平均观察杂合度(Ho)和平均期望杂合度(He),检验Hardy-Weinberg平衡并进行遗传分化分析。结果表明:该群体的Na、Ho和He分别为3.05±0.71,0.703 7±0.019 2和0.574 6±0.023 1,3窝仔猪的He分别为0.558 3±0.029 3,0.552 0±0.037 3和0.549 2±0.030 8,且差异不显著(P>0.05);经完全枚举法检验,A窝和C窝分别有3个和5个基因座偏离Hardy-Weinberg平衡;经U检验,A窝和C窝分别有4个和6个基因座存在杂合子过剩,仅C窝1个基因座表现出杂合子缺失现象。说明该猪群遗传多样性较低,处于低度杂合状态,窝系之间不存在遗传分化。

To research genetic background of Bama miniature pigs used in the small- scale preservation test under a barrier environment, the genetic diversity and structure of three litters of the piglets produced by three sows each mated by a same boar in the first generation of experi- mental Bama miniature pigs （BM/HVRI） which have been raised in barrier environment were analyzed using 19 microsatellite loci. The number of alleles （Na）, observed heterozygosity （Ho）, expected heterozygosity （He）, Hardy -Weinberg equilibrium tests and population genetic structure were calculated or estimated using relevant formulas or models. The results showed that the average Na, Ho, and He in the population were 3.05 ± 0.71,0. 703 7 ± 0. 019 2 and 0. 574 6± 0. 023 1, respectively. Meanwhile, the expected heterozygosities of the three litters of piglets were 0. 558 3±0. 029 3,0. 552 0 ± 0. 037 3 and 0. 549 2 ± 0. 030 8, respectively, showing no difference from each other （ P 〉 0.05 ）. The test results for the complete enumeration method showed that there were three and five loci being deviated from Hardy - Weinberg equilibri- um from the piglets in the litter A and C, respectively. And the results of the U tests showed that there were four loci in the litter A and six loci in the litter C, which had heterozygote excess, but only one locus in litter C had heterezygosity deficit. The results indicate that there is low ge- netic diversity in the population with the low heterozygous state ; there is no genetic differentiation between the litters.