Genetic effects of polymorphisms of candidate genes associated with ovary development and egg production traits in ducks.

ABSTRACT

Duck eggs are highly nutritious, and demand for consumption has markedly increased in the growing human population, resulting in the need to increase production. Egg production is dependent on the reproductive performance of animals, a trait that is not highly heritable. Improving reproductive performance, therefore, is an essential aim of breeders performing genetic selection to increase egg production. The ovary has received much attention by breeders because of its importance in the production and release of eggs. The ovary, therefore, has been intensely studied to identify the candidate genes and the polymorphisms associated with egg-laying traits. The expression of these genes in the ovary indicates the potential for involvement in ovarian follicular development. The expression of the growth hormone, follicle-stimulating hormone receptor, prolactin, ovoinhibitor, melatonin receptor, and insulin-like growth factor-2 genes in the ovary has been studied, and polymorphisms have been identified that are related to egg-laying traits. The single nucleotide polymorphisms of these genes help with the identification of novel genetic markers that assist in selecting the ducks with the most desirable genotypes for egg production. This approach to genetic selection is more effective than the traditional method used to select animals for egg production. With this review, therefore, there is a summarization of genetic effects of polymorphisms in candidate genes related to ovarian development and egg production traits in ducks.