Inspection the Linkage between Bovine GDF9 SNPs and Calving Rate (Superovulation) in Holstein Friesians Cows

Abstract

This study prepared to explore the relation between Growth Differentiation Factor 9 (GDF9) genotypes and calving rate, Follicle-stimulating hormone (FSH) and Estradiol (E2) in Iraqi Holstein Friesians breed. Fifteen blood samples collected from a mother of DZTB (with high calving rate records), another blood sample collected from 15 SB cows, the DNA extracted and six primers designed for PCR and sequencing analysis. The FSH and E2 level tested through estrus phase for the two groups (10 n for each group). The sequence evaluation revealed that presence 2 single nucleotide polymorphisms (SNPs) in exon II; A (1109) T and G (1133) A.\xa0The genotypic frequency for mutant genotypes was higher significantly (P<0.01) in DZTB cows (with calving rate) than wild at the same loci. On the other hand, the wild genotypes recorded higher significant increment (P<0.01) for SB cows when compared with mutant genotypes in the same loci. Moreover,\xa0a significant rise (P<0.05) was reported in E2 and FSH levels for DZTB cows and mutant genotypes\xa0(P<0.01) against SB cows and wild genotypes respectively\xa0in 0 and 24 h of estrus phase. Non-significant differences recorded in E2 concentration between the same genotypes at same period.\xa0In conclusion, the GDF9\xa0exon II SNPs increase the calving rate in Holstein Friesians cows. The blood FSH and E2 concentrations are higher in the mother of DZTB may control the superovulation. Finally, these SNPs can be considered as markers to accelerate the breeding programs and used in embryo transfer and in vitro embryo production for Iraqi Holstein Friesians cows breed.