Various studies had shown that the FecB gene (also known as BMPRIB, BMPR1B or ALK-6) was the major gene influencing sheep litter size, for which its SNPs’ variations were reportedly linked. Yet, surprisingly, there was no published information on the insertion/deletion (indel) variation of this gene. Herein, using a population of Chinese Australian White sheep (n = 932), we identified five novel indels in the different introns of the FecB gene. Among them, the 12-bp indel was distinguished as a splicing region variation that was completely linked to the 17-bp indel. Analysis of variance revealed that only the 10-bp indel was significantly associated with sheep litter size (P = 0.010), for which the deletion/deletion (DD) genotype was the harmful one for fecundity. Nevertheless, the combined genotypes of these five indels were significantly (P = 0.033) correlated with the litter size. These findings would provide fresh insight into developing a sounder basis to accelerate molecular breeding in sheep via DNA markers in a marker-assisted selection strategy.

各种研究表明，FecB基因（也称为BMPRIB，BMPR1B或ALK-6）是影响绵羊垫料大小的主要基因，据报道其SNP的变异与之相关。然而，令人惊讶的是，没有关于该基因的插入/缺失（插入/缺失）变异的公开信息。在这里，我们使用澳大利亚华人白羊种群（n = 932），在FecB基因的不同内含子中鉴定出五个新的indel 。其中，12 bp插入缺失被认为是与17 bp插入缺失完全连锁的剪接区域变异。方差分析显示，只有10 bp插入缺失与绵羊产仔数显着相关（P = 0.010），因此删除/删除（DD）基因型是繁殖力的有害基因。然而，这五个插入缺失的组合基因型与产仔数显着相关（P  = 0.033）。这些发现将为在标记辅助选择策略中通过DNA标记加速绵羊分子育种的合理基础提供新的见识。