Polymorphism of BMP4 gene in Indian goat breeds differing in prolificacy

Bone morphogenetic proteins (BMPs) are members of the TGF-β (transforming growth factor-beta) superfamily, of which BMP4 is the most important due to its crucial role in follicular growth and differentiation, cumulus expansion and ovulation. Reproduction is a crucial trait in goat breeding and based on the important role of BMP4 gene in reproduction it was considered as a possible candidate gene for the prolificacy of goats. The objective of the present study was to detect polymorphism in intronic, exonic and 3' un-translated regions of BMP4 gene in Indian goats. Nine different goat breeds (Barbari, Beetal, Black Bengal, Malabari, Jakhrana (Twinning>40%), Osmanabadi, Sangamneri (Twinning 20-30%), Sirohi and Ganjam (Twinning<10%)) differing in prolificacy and geographic distribution were employed for polymorphism scanning. Cattle sequence (AC_000167.1) was used to design primers for the amplification of a targeted region followed by direct DNA sequencing to identify the genetic variations. Single nucleotide polymorphisms (SNPs) were not detected in exon 3, the intronic region and the 3' flanking region. A SNP (G1534A) was identified in exon 2. It was a non-synonymous mutation resulting in an arginine to lysine change in a corresponding protein sequence. G to A transition at the 1534 locus revealed two genotypes GG and GA in the nine investigated goat breeds. The GG genotype was predominant with a genotype frequency of 0.98. The GA genotype was present in the Black Bengal as well as Jakhrana breed with a genotype frequency of 0.02. A microsatellite was identified in the 3' flanking region, only 20 nucleotides downstream from the termination site of the coding region, as a short sequence with more than nineteen continuous and repeated CA dinucleotides. Since the gene is highly evolutionarily conserved, identification of a non-synonymous SNP (G1534A) in the coding region gains further importance. To our knowledge, this is the first report of a mutation in the coding region of the caprine BMP4 gene. But whether the reproduction trait of goat is associated with the BMP4 polymorphism, needs to be further defined by association studies in more populations so as to delineate an effect on it.

Altered Expression of GDF9 and BMP15 Genes in Granulosa Cells of Diminished Ovarian Reserve Patients: A Case-Control Study

OBJECTIVE

Diminished ovarian reserve (DOR) is a challenging issue encountered during assisted reproductive technology. Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) belong to the transforming growth factor-beta (TGF-β) superfamily which are essential for folliculogenesis. We aimed to the evaluation of the GDF9 and BMP15 expression in the granulosa cells (GCs) of DOR patients.

MATERIALS AND METHODS

This case-control study included 14 women with DOR and 12 controls, who were between 28- 40 years of age undergoing controlled ovarian stimulation with a gonadotropin releasing hormone (GnRH) antagonist protocol. DOR patients were selected by the Bologna criteria. The GCs were extracted from the aspirated follicular fluids and RNA isolated from this. The fold change of gene expressions was assessed by real-time polymerase chain reaction (PCR).

RESULTS

GDF9 expression in patients was 0.23 times lower than the control group, which was significant (P<0.0001). BMP15 expression in patients was 0.32 times lower than the control group, which was significant (P<0.0001). The number of archived oocytes, MII, and two pronuclei (PN) embryos was higher in the control group and these differences were statistically significant (P<0.05).

CONCLUSION

Given that GDF9 and BMP15 are specifically involved during follicular recruitmen., we expect expression of these two genes in DOR patients which is greatly reduced by reducing follicular reserve.