A novel 12 bp deletion within goat <i>LHX4</i> gene significantly affected litter size

The LIM homeobox transcription factor 4 (LHX4) gene plays a critical role in regulating the development of the pituitary and the secretion of growth hormone (GH) and prolactin (PRL) associated with reproduction. Thus this gene may affect litter size. Herein, the aim of this study is to detect the novel insertion/deletion (indel) within the LHX4 gene as well as to test its association with litter size in 1149 Shaanbei white cashmere goats. Herein, a novel 12 bp indel (NC_030823.1:g.60001011_60001022delGGGGAGGAGGGG) was firstly found, which was located in the first intron. Meanwhile, three genotypes were detected in Shaanbei white cashmere goats, and the allelic frequencies of I and D were 0.593 and 0.407, respectively. Interestingly, the genotype distributions between mothers of single-lamb (n = 895) and multi-lamb (n = 254) groups within Shaanbei white cashmere goats were significantly different, implying that the 12 bp indel might affect the litter size. Furthermore, the association analysis was carried out to find out that the 12 bp indel was significantly associated with litter size in the analyzed goat population (P &lt; 0.05). The litter sizes of genotype DD and ID individuals were superior to those of genotype II (P &lt; 0.05). These findings suggest that this locus could be considered as a genetic marker for goat breeding, enriching the research category of functional genome of goats