Relationship between SNPs of POU1F1 Gene and Litter Size and Growth Traits in Shaanbei White Cashmere Goats

SIMPLE SUMMARY: POU (Pit-Oct-Unc) class 1 homeobox 1 (POU1F1, or Pit-1) is a key transcription factor that directly regulates pituitary hormone-related genes and was considered as a candidate gene for reproduction and growth traits in goat breeding. Three important single nucleotide polymorphisms (SNPs), c.682G > T, c.723T > G and c.837T > C, were found in Shaanbei white cashmere (SBWC) goats by direct DNA sequencing, and c.876 + 110T > C was monomorphic. Further analyses showed that the c.682G > T and c.837T > C loci were associated with litter size, and c.682G > T, c.723T > G and c.837T > C strongly affected growth traits (p < 0.05). It is an interesting phenomenon for this population that individuals with the same genotypes had more offspring and that their body status was also better. Thus, we speculated that there was a positive correlation between growth and lambing ability. Besides this, female goats with H3H7 (combined from haplotype 3 and 7) diplotype (GTTT-TTTT), which was consistent with the combination of the optimal genotype of four SNPs, had a better litter size and growth status than other diplotypes. This study provides the first association analyses between the SNPs of POU1F1 and economic traits in SBWC goats, which could be considered as effective SNP markers for genomic selection in goat breeding. ABSTRACT: POU (Pit-Oct-Unc) class 1 homeobox 1 (POU1F1, or Pit-1) is a transcription factor that directly regulates pituitary hormone-related genes, as well as affects the reproduction and growth in mammals. Thus, POU1F1 gene was investigated as a candidate gene for litter size and growth performance in goats. In the current study, using direct DNA sequencing, c.682G > T, c.723T > G and c.837T > C loci were genotyped in Shaanbei white cashmere (SBWC) goats (n = 609), but c.876 + 110T > C was monomorphic. Besides, the c.682G > T locus was first identified by HinfI (Haemophilus influenzae Rf) restriction endonuclease. Association analysis results showed that the c.682G > T, c.837T > C loci and diplotypes were significantly associated with goat litter size (p < 0.05). The positive genotypes were GT and TT for the two SNPs, respectively, and the optimal diplotype was H3H7 (GTTT-TTTT). On the other hand, the c.682G > T, c.723T > G and c.837T > C strongly affected growth traits and body measurement indexes in SBWC goats (p < 0.05). The positive genotypes or allele of these SNPs were GT, G and TT, respectively. Additionally, the goats with H3H7 diplotype also had a greater growth status than others (p < 0.05). Here, individuals with same genotype had both a better litter size and growth traits, showing a positive correlation between these economic traits. Meanwhile, the positive genotypes of four SNPs were combined to obtain the optimal diplotype, which was also H3H7. These SNPs, especially the diplotype, could be used for the genomic selection of excellent individuals with a greater litter size and better growth status in goat breeding.