Abstract

Lysine demethylase 3B (KDM3B) gene is a histone demethylase, demonstrating specific demethylation of the histone H3 lysine 9. It was detected as a sheep reproductive candidate gene by genome-wide scans, and related studies also showed its significance in female reproductive process. However, rare study researched its polymorphism. Herein, we hypothesized that the polymorphisms of KDM3B gene were associated with sheep reproduction traits. A 7-nt nucleotide sequence variant (rs1088697156) within KDM3B gene was identified in a total of 888 individuals, including the Australian White (AUW) sheep and Lanzhou Fat-tailed (LFT) sheep. II (insertion/insertion) and ID (insertion/deletion) genotypes of 7-nt variant were detected, which were at Hardy-Weinberg equilibrium (HWE) in detected breeds. Association analysis illustrated the 7-nt variant was significantly associated with the litter size, duration of pregnancy, live lamb number, live lamb rate, stillbirth number, stillbirth rate of average and different parity (P < 0.05) in AUW sheep. Moreover, ‘ID’ was the dominant genotype with excellent consistency in reproductive traits. It is instrumental to select individuals with ID genotype for improving the sheep reproduction traits. These findings suggest that the 7-nt variant within KDM3B gene can be used as a candidate marker of reproduction traits for sheep breeding improvement by marker-assisted selection.

摘要

赖氨酸去甲基化酶3B（KDM3B）基因是一种组蛋白去甲基化酶，表现出组蛋白H3赖氨酸9的特异性去甲基化作用。通过全基因组扫描被检测为绵羊繁殖候选基因，相关研究也表明其在雌性繁殖过程中的意义。然而，很少有研究对其多态性进行研究。在此，我们假设KDM3B基因多态性与绵羊繁殖性状相关。KDM3B内的 7-nt 核苷酸序列变体 (rs1088697156)基因在总共 888 个个体中被鉴定，包括澳大利亚白 (AUW) 羊和兰州肥尾 (LFT) 羊。检测到 7-nt 变体的 II（插入/插入）和 ID（插入/缺失）基因型，它们在检测到的品种中处于 Hardy-Weinberg 平衡（HWE）。关联分析显示7-nt变异与AUW绵羊产仔数、妊娠期、活羔数、活羔率、死胎数、平均胎次和不同胎次死胎率显着相关（P  < 0.05）。此外，'ID'是显性基因型，在繁殖性状上具有极好的一致性。选择具有ID基因型的个体对改良绵羊繁殖性状具有重要意义。这些发现表明KDM3B中的 7-nt 变体基因可作为繁殖性状的候选标记，通过标记辅助选择进行绵羊育种改良。