Genetic diversity of ghrelin gene SNPs in Nigerian Indigenous chickens and its influence on growth traits

Abstract

Genetic diversity in functional genes, such as the ghrelin gene, plays a significant role in understanding growth and productivity traits in chickens. This study investigates the genetic variability of the ghrelin gene in Nigerian indigenous chickens (NICs) and evaluates its potential influence on growth traits. Nigerian indigenous chickens are renowned for their adaptability to harsh environments, disease resistance, and cultural significance, but they are characterized by low productivity compared to exotic breeds. Blood was collected from samples of three major ecotypes of NICs: Naked Neck, Normal Feather, and Frizzle Feather. DNA was extracted, and polymorphisms in the ghrelin gene were identified using PCR amplification and sequencing techniques. Bioinformatic analyses were conducted to assess nucleotide diversity, haplotype frequency, and evolutionary dynamics of the gene. Phenotypic data on growth traits, including body weight, body length, chest circumference, shank length, beak length, comb length, and comb height, were recorded at different growth stages and correlated with identified ghrelin gene variants using statistical models. Results revealed high genetic diversity within the ghrelin gene, with several novel single-nucleotide polymorphisms (SNPs) detected. The polymorphisms were unevenly distributed across the gene regions, with some variants significantly associated with growth traits. Specific alleles were linked to enhanced BDW, BDL, CC, SHKL, BKL, CL, and CH, suggesting their potential role as genetic markers for growth performance. This research contributes to the growing knowledge on the genetic basis of growth traits in NIC populations. It emphasizes the need for conservation and sustainable utilization of NICs' genetic resources.