Genetic diversity and differentiation of some Nigerian indigenous cattle breeds at IGF-1 gene locus

A study was conducted to determine the genetic diversity and differentiation in selected in digenous breeds of cattle in Nigeria at Insulin-Like Growth Factor 1 gene locus. Ninety-six (96) cattle (n = 24 per breed) were sampled purposively across Adamawa, Taraba, Gombe and Sokoto States. Blood samples were collected from the animals via jugular venipuncture. DNA was extracted using a DNA purification kit, and quality and quantity were assessed with a NanoDrop-1000 UV spectrophotometer. Genomic DNA was extracted from whole blood and genotyped for an IGF-1 fragment using PCR-RFLP with the SnaBI restriction enzyme using Zymo Quick DNA TMMini prep kit. Data collected were subjected to F Statistics analysis using GenAIEx software package. Analysis of Molecular Variance (AMOVA) of cattle revealed 61% of within population, 30% of the variance was attributed to among individuals and 9% was due to among population. The TT genotype appeared to be the highest, followed by CT genotype whereas the CC genotype was the least. Complete polymorphism was observed at the IGF-1 gene locus and the gene flow N (nm) over all populations for each locus was (2.595) and within population inbreeding coefficient (FIS) per population was (0.310). The expected heterozygosity (0.444) and unbiased expected heterozygosity (0.454) also appeared to be preponderant in Sokoto Gudali cattle breed compared to others breeds. Restriction Fragment Length Polymorphism (RFLP) marker revealed high level of genetic variations and diversity at IGF-1 gene locus among the population of cattle studied.