Detection of Polymorphism in Insulin-Like Growth Factor I Gene in Fulani and Yoruba Ecotype Chickens

Abstract

This research examined polymorphism in the insulin-like growth factor I (IGF-1) gene of native Nigerian chickens
(Fulani and Yoruba ecotypes) using polymerase chain reaction-restriction fragment length polymorphism (PCRRFLP)
analysis. This study examined 98 chickens (50 Fulani and 48 Yoruba ecotypes) with approximately 2 mL
of blood collected from the wing vein for DNA extraction. Genetic variation was tested by digesting PCR products
with PstI. Two alleles (C and T) and three genotypes (CC, CT, and TT) were identified in both ecotypes,
confirming that the IGF-1 locus was polymorphic. Frequencies of the T allele and TT genotype were higher in the
populations. Chi-square test revealed a departure from the Hardy- Weinberg equilibrium in the Fulani ecotype,
but not in the Yoruba ecotype. Observed heterozygosity was significantly lower than the expected, implying
inbreeding. The genetic diversity was fairly high while the genetic distance was low, suggesting high genetic
similarity between the two ecotypes. Additional studies are needed to determine the relationship between IGF-1
polymorphism and productivity traits.