Alpha % Indigenous chicken % Gene % Sequence
KR nema
The chicken Insulin-like growth factor 1 (IGF1) is a candidate gene for
growth, body composition and metabolism, skeletal characteristics and growth
of adipose tissue and fat deposition in chickens. It is mapped to 165.95 cM
on chromosome 1 and composed of four exons and three introns, spanning more
than 50 kb. Genomic DNA was extracted from blood samples collected from the
experimental birds using Qiagen DNA extraction kits. Polymersae chain
reaction (PCR) was carried out using established primers. The PCR amplicon
involving 5?untranslated region were sequenced. The sequences were analysed
to identify polymorphisms, their genetic diversities and evolutionary
relationships among three strains of Nigerian indigenous chickens [Frizzle
Feathered (7), Normal Feathered (19) and Naked Neck (19), and the Arbor Acre
broiler chicken (17)]. Nucleotide sequences generated were edited and
aligned using Codon Code Aligner. Diversity analysis was done using DnaSp
while MEGA6 software was used to plot phylogenetic tree using maximum
likelihood method. A total of nineteen single nucleotide polymorphisms
(SNPs) were detected from 560 bp portions of the 5?UTR among the four
chicken populations studied with none detected in the Frizzle feathered
chicken. The Naked neck chicken had the highest number of SNP?s (13),
haplotypes (6), haplotype diversity (0.778), nucleotide diversity (0.00487),
average number of nucleotide differences (2.725), highest number of
polymorphic (segregating) sites (13), parsimony informative site (5) and
singleton variable site (8). The Naked neck chicken therefore had the
highest rate of mutation and degree of allelic variation compared to other
chicken strains used in this study. The phylogenetic tree showed that small
genetic differentiation exists among the chicken populations studied. Some
of the SNPs are newly discovered; hence, association between these alleles
and productive traits in Nigerian native chickens is desirable in future
studies.