Polymorphism and diversity studies of insulin-like growth factor I gene among indigenous and FUNAAB Alpha chicken breeds in Nigeria

Résumé

The Insulin-like growth factor gene (IGF-1) is an important candidate gene responsible for growth, body composition, metabolism, skeletal characteristics and fat deposition in chicken. Little or no work has been done on the sequence analysis of IGF1 gene in FUNAAB Alpha chicken breed. Therefore, this study was designed to examine the polymorphisms and genetic diversities of the IGF-1 gene among Nigerian indigenous and improved indigenous (FUNAAB Alpha) chicken breeds. A total of 120 chickens comprising of 20 each from Frizzle feathered, Normal Feathered, Naked neck, FUNAAB-Alpha 1 (DHR), FUNAAB-Alpha 2 (TRH) and Arbor Acre were used for the study. Approximately 2 ml of blood collected from each chicken was used for genomic DNA extraction following the protocol of Qiagen DNA extraction kits. PCR was carried out and the PCR amplicons were outsourced to Stabvida Laboratory, Portugal for sequencing. The results of the analysis indicated a total of 21 polymorphic sites and 12 haplotypes across all the sampled chickens. The number of haplotypes varied from five in DHR and four in Naked neck to three and one in Arbor Acre and Frizzle feathered, respectively. The naked neck was the most superior in terms of nucleotide diversity per site (0.00307), nucleotide difference (1.67974) and the number of variable sites, indicative of its evolutionary adaptability to the prevailing environmental conditions of the tropics and high potential as genetic resources for domestic chicken improvement.