College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; and College of Animal Science and Technology, Shandong Agricultural University, Tai'an 271000, China.
College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
Reprod Fertil Dev. 2020 Feb;32(3):267-273. doi: 10.1071/RD19035.
Mitochondrial DNA (mtDNA) has been widely associated with complex traits in farm animals. The present study evaluated the effects of mtDNA on litter size in pigs. Mitogenome sequencing of 1017 sows distinguished 232 variations, including 229 single nucleotide polymorphisms and three indels, which constituted 11 haplotypes and further clustered into two haplogroups that differed significantly (P<0.05) in litter size. In order to explain the associations between the effect of haplogroup on litter size and different maternal origins, extant mitogenome sequences were used for phylogenetic or principal component analyses. The results of these analyses led to the identification of two groups, representing Chinese and European origins. The haplotypes corresponding to high litter size were all in the Chinese cluster, whereas haplotypes corresponding to low litter size were all in the European cluster. The results of this study suggest that the effect of haplogroup on litter size in the pig could be caused by diverse maternal origins, and that mtDNA haplogroup may be a marker for genetic selection for pig litter size.
线粒体 DNA（mtDNA）与农场动物的复杂特征广泛相关。本研究评估了 mtDNA 对猪产仔数的影响。对 1017 头母猪的线粒体基因组测序区分了 232 种变异，包括 229 个单核苷酸多态性和 3 个插入缺失，这些变异构成了 11 种单倍型，并进一步聚类为两个单倍群，在产仔数上存在显著差异（P<0.05）。为了解释单倍群对产仔数的影响与不同母系起源之间的关联，使用现存的线粒体基因组序列进行了系统发生或主成分分析。这些分析的结果导致了两个组的鉴定，代表中国和欧洲的起源。与高产仔数相对应的单倍型都在中国人群中，而与低产仔数相对应的单倍型都在欧洲人群中。本研究的结果表明，单倍群对猪产仔数的影响可能是由不同的母系起源引起的，并且 mtDNA 单倍群可能是猪产仔数遗传选择的一个标记。
