Association of PRLR, IGF1, and LEP genes polymorphism with milk production and litter size in Egyptian Zaraibi goat

Studying variation in genes responsible for physiological characters is important to enhance goat productive and reproductive efficiency. This study aimed to detect specific nucleotide polymorphisms in prolactin receptor (PRLR), insulin-like growth factor (IGF1), and leptin (LEP) genes and their correlation with milk production (MP) and litter size (LS) traits in Zaraibi goat. PCR-SSCP products of different patterns of each gene were sequenced and aligned to reveal two mutations (T > C) and (G > A) in 3′UTR of PRLR gene and registered on NCBI with accession numbers OM418863 for TT and OM418864 for CT, while (G > A) variation was registered as OM418861 for GG and OM418862 for AG in exon 10. TT, CT, AG, and GG genotypes were distributed in the studied animals with frequencies 0.43, 0.57, 0.65, and 0.35, respectively. While alleles C, T, A, and G frequencies were 0.28, 0.72, 0.32, and 0.68, respectively. CT and AG genotypes associated significantly (P < 0.05) with higher MP and LS, respectively. By studying the haplotypes of PRLR, C-A and T-A were associated with the highest and the lowest level of MP, respectively. For LS, T-A and C-G showed significant correlation with the highest and the lowest rate, respectively. Regarding IGF1 gene, two polymorphisms were detected; T74C at exon 4 which registered on NCBI as OM418860, and combined mutations as ins. G470, A531G, and T534C (PP genotype) at 5′ flanking region that registered as OM418859. For LEP, only one polymorphism was found in intron 2 (G281A) which submitted to NCBI as OM418855. All detected polymorphisms have shown to be involved in regulating the MP or LS as reproductive traits in goat.