Abstract

Retinoid acid receptor related orphan receptor alpha (RORA) transcribes steroid-related genes to regulate estrogen synthesis. As an important reproductive trait, litter size relates to estrogen synthesis. Therefore, it is important to investigate the association between RORA gene and sheep litter size. In this study, one 23-bp nucleotide sequence mutation was identified in intron 1 of RORA gene in 532 female Australian White Sheep. Moreover, the polymorphic information content (PIC) values of this locus was 0.219. The litter size of ID genotype was significantly better than II genotype and DD genotype in the second born litter size (p < 0.05). This loci was related to third born litter size and the ID is the dominant genotype (p < 0.05). The association between combined genotypes and average litter size showed that sheep with heterozygote (ID) genotypes had larger lamb than homozygous (DD and II) genotypes. To sum, this study provided theoretical references for the comprehensively research of the function of RORA gene and the breeding of Australian White Sheep. The 23-bp indel variants could be considered as molecular markers for the second and third born litter size of sheep for MAS breeding.

摘要

维甲酸受体相关孤儿受体α ( RORA ) 转录类固醇相关基因以调节雌激素合成。作为一个重要的繁殖性状，产仔数与雌激素合成有关。因此，研究RORA基因与羊窝产仔数之间的关系非常重要。本研究在 532 只雌性澳大利亚白羊的RORA基因内含子 1 中鉴定出一个 23 bp 核苷酸序列突变。此外，该基因座的多态信息含量（PIC）值为0.219。二胎产仔数中ID基因型的产仔数显着优于II基因型和DD基因型（p  < 0.05）。该位点与第三胎产仔数有关，ID 是显性基因型（p  < 0.05)。组合基因型与平均产仔数之间的关联表明，杂合子 (ID) 基因型的绵羊比纯合子 (DD 和 II) 基因型的羔羊更大。综上所述，本研究为RORA基因功能的综合研究和澳大利亚白羊的选育提供了理论参考。23 bp indel 变体可被视为用于 MAS 育种的第二胎和第三胎羊的分子标记。