Current status of molecular genetics research of goat fecundity

- Reproductive traits are extremely important to the goat industry.
- Molecular genetics has led to the discovery of candidate genes with substantial effects on the fecundity trait.
- The identified candidate genes for fecundity might contribute towards molecular breeding to enhance productivity of goats.

Reproductive traits are extremely important to the goat industry because moderate increase in litter size can lead to large profit. Traditional selection for improving litter size is difficult due to sex-limited nature and low heritability of the trait (5-10%). In addition, the lack of knowledge on the number of the genes controlling this trait and the possible gene interactions are the other limitations for this trait. Molecular genetics can overcome these limitations offering new opportunities for the improvement of reproductive traits, as it supplies tools to analyze genetic variability directly at the DNA level with the possibility of detecting the individual genes influencing the reproductive capability. For the last decade, molecular genetics has led to the discovery of individual genes or candidate genes with substantial effects on the reproductive trait viz. BMPR1B, GDF9, BMP15, FSHβ, FSHR, POU1F1, PRLR, KiSS-1, GPR54, GH, INH, CART, GnRH, GnRHR, LHβ, BMP4, KITLG, MT2, CYP21 and AA-NAT. Despite the progress made in goat fecundity studies, it's hard to satisfy the actual application because the reproductive traits are complex quantitative traits involving multiple genes, loci and interactions. So it is important to analyze the combined effect of multiple genes or loci on reproductive traits. Little progress has been made on understanding interaction between genes, gene and environment, and genetic effect analysis. Thus the need of the hour is to identify more functional genes, clarify molecular mechanism of action and regulatory network and to resort to more holistic approaches like genomic selection which can tremendously accelerate the goat improvement.