Faculty of Agricultural Sciences, Research group in Animal Reproduction and Genetic Improvement, University of Sucre, Sucre, Colombia.
Trop Anim Health Prod. 2021 Mar 13;53(2):206. doi: 10.1007/s11250-021-02651-0.
Colombian-haired sheep (OPC) is a creole breed with very good adaptation to the tropical conditions of our country. In sheep, it has been shown that the litter size (LS) is associated with ovulation rate, the number of fertilized eggs, and embryo survival. Also, LS is determined by genetic and environmental effects. In this sense, the receptor 1B of bone morphogenetic protein (BMPR-1B) has been described as a genetic factor. Therefore, the aim of the present work was to characterize and associate the SNP C864T in the BMPR-1B gene with LS in the specific OPC biotypes Ethiopian and Sudan.
Reproductive history (LS, number of calving in the mother, identification of the father, conception year, and conception period) of 200 OPC sheep was assessed. Additionally, sheep were genotyped by sequencing for the SNP C864T. An association between LS, reproductive history, and C864T variation was performed using a GLM fixed-effect model.
The frequency of the T allele (0.75 ± 0.03) was higher than that of the C allele (P<0.05). The genotypic frequencies were 0.55 ± 0.06, 0.38 ± 0.04, and 0.07 ± 0.01, for TT, TC, and CC, respectively. An average value of He (0.37 ± 0.03) and HWE (P=0.97) was found. The LS found was 1.45 ± 0.15. This varied, between biotypes, with number of calving in the mother, with the father, and at the time of conception (P <0.05).
The LS varied between genotypes (P<0.05). The CC genotype was the most prolific (1.81 ± 0.4), followed by the heterozygous (1.45 ± 0.04) and the TT homozygous (1.09 ± 0.04). However, we did not find a variation between biotypes within the genotypes (P>0.05). In conclusion, the polymorphism target in the exon 9 of the BMPR-1B gene and non-genetic factors affected significantly the litter size in the OPC.
哥伦比亚羊毛羊（OPC）是一种具有很好的热带条件适应能力的克里奥尔品种。在绵羊中，已经表明产仔数（LS）与排卵率、受精卵子数量和胚胎存活率有关。此外，LS 由遗传和环境因素决定。在这方面，骨形态发生蛋白受体 1B（BMPR-1B）已被描述为一种遗传因素。因此，本工作的目的是表征和关联 BMPR-1B 基因中的 SNP C864T 与埃塞俄比亚和苏丹特定 OPC 生物型的 LS。
评估了 200 只 OPC 绵羊的繁殖史（LS、母亲的产仔数、父亲的鉴定、配种年份和配种期）。此外，通过测序对绵羊进行 SNP C864T 基因分型。使用固定效应模型的 GLM 对 LS、繁殖史和 C864T 变异之间的关联进行了分析。
T 等位基因的频率（0.75 ± 0.03）高于 C 等位基因（P<0.05）。基因型频率分别为 0.55 ± 0.06、0.38 ± 0.04 和 0.07 ± 0.01，分别为 TT、TC 和 CC。发现平均 He 值（0.37 ± 0.03）和 HWE（P=0.97）。发现的 LS 为 1.45 ± 0.15。这在生物型之间有所不同，与母亲的产仔数、父亲和配种时间有关（P<0.05）。
LS 在基因型之间存在差异（P<0.05）。CC 基因型的产仔数最多（1.81 ± 0.4），其次是杂合子（1.45 ± 0.04）和 TT 纯合子（1.09 ± 0.04）。然而，我们没有发现基因型内生物型之间的差异（P>0.05）。综上所述，BMPR-1B 基因外显子 9 的多态性靶标和非遗传因素显著影响 OPC 的产仔数。
