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

Abstract 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 single nucleotide polymorphisms (SNPs) (T>C) and (G>A) in 3’UTR of PRLR gene and registered with accession numbers OM418863 for TT and OM418864 for CT, while (G>A) SNP 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 SNPs were detected; T74C at exon 4 which registered as (OM418860), and combined SNPs as ins. G470, A531G and T534C (PP genotype) at 5’ flanking region that registered as (OM418859). For LEP, only one SNP was found in intron 2 (G281A) which submitted to GenBank as (OM418855). All detected SNPs have shown to be involved in regulating the MP or LS as reproductive traits in goat.