Córdoba S, Balcells I, Castelló A, Ovilo C, Noguera J L, Timoneda O, Sánchez A
Departament de Genètica Animal, Centre de Recerca en Agrigenòmica (CRAG), Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain.
Departamento de Mejora Genética Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (SGIT-INIA), 28040 Madrid, Spain.
Sci Rep. 2015 Oct 5;5:14416. doi: 10.1038/srep14416.
Prolificacy can directly impact porcine profitability, but large genetic variation and low heritability have been found regarding litter size among porcine breeds. To identify key differences in gene expression associated to swine reproductive efficiency, we performed a transcriptome analysis of sows' endometrium from an Iberian x Meishan F2 population at day 30-32 of gestation, classified according to their estimated breeding value (EBV) as high (H, EBV > 0) and low (L, EBV < 0) prolificacy phenotypes. For each sample, mRNA and small RNA libraries were RNA-sequenced, identifying 141 genes and 10 miRNAs differentially expressed between H and L groups. We selected four miRNAs based on their role in reproduction, and five genes displaying the highest differences and a positive mapping into known reproductive QTLs for RT-qPCR validation on the whole extreme population. Significant differences were validated for genes: PTGS2 (p = 0.03; H/L ratio = 3.50), PTHLH (p = 0.03; H/L ratio = 3.69), MMP8 (p = 0.01; H/L ratio =4.41) and SCNN1G (p = 0.04; H/L ratio = 3.42). Although selected miRNAs showed similar expression levels between H and L groups, significant correlation was found between the expression level of ssc-miR-133a (p < 0.01) and ssc-miR-92a (p < 0.01) and validated genes. These results provide a better understanding of the genetic architecture of prolificacy-related traits and embryo implantation failure in pigs.
繁殖力可直接影响猪的养殖效益，但已发现猪品种间产仔数存在较大的遗传变异且遗传力较低。为了确定与猪繁殖效率相关的基因表达关键差异，我们对伊比利亚猪×梅山猪F2群体妊娠第30 - 32天母猪的子宫内膜进行了转录组分析，根据其估计育种值（EBV）分为高产（H，EBV > 0）和低产（L，EBV < 0）繁殖力表型。对每个样本进行mRNA和小RNA文库的RNA测序，鉴定出H组和L组之间差异表达的141个基因和10个miRNA。我们基于它们在繁殖中的作用选择了4个miRNA，以及5个差异最大且正向定位到已知繁殖数量性状位点的基因，用于在整个极端群体上进行RT-qPCR验证。验证了基因PTGS2（p = 0.03；H/L比值 = 3.50）、PTHLH（p = 0.03；H/L比值 = 3.69）、MMP8（p = 0.01；H/L比值 = 4.41）和SCNN1G（p = 0.04；H/L比值 = 3.42）存在显著差异。虽然所选miRNA在H组和L组之间显示出相似的表达水平，但发现ssc-miR-133a（p < 0.01）和ssc-miR-92a（p < 0.01）的表达水平与验证基因之间存在显著相关性。这些结果有助于更好地理解猪繁殖力相关性状和胚胎着床失败的遗传结构。
