Genetic variation and phylogenetic relationships of Nigerian indigenous and commercial pigs in southwestern Nigeria

This work presents an initial observation in a continuing study of genetic diversity and relationships
of Nigerian Indigenous Pig (NIP) in southwestern Nigeria with commercial pigs using microsatellite
markers. Sixty individuals including Nigerian indigenous pigs (NIP) (n=25), exotic (n=25), and
crosses between the exotic pigs (n=10) were genotyped based on eight microsatellite markers. The
mean number of alleles observed in the overall population of the three populations was 3.63±0.36.
Allele frequency ranged from 0.00 to 1.00 from the 39 alleles obtained within the population. These
allele frequencies obtained from the interpretation for the microsatellite loci across the three
populations were polymorphic except for S0101 which was monomorphic. The mean number of the
effective allele was 2.22±0.17. The means obtained in this study for observed and
expected heterozygosities were 0.53 and 0.50 respectively. The F-statistics showed a reduction in
heterozygosity at various loci across the population. The low mean level of gene flow among the
population was estimated to be 9.18±3.59. The very low genetic differentiation between NIP
and commercial pigs reflects high gene flow. The phylogenetic tree separated the NIP from the two
populations while the exotic and the crosses clustered closely. These results show that there is low
genetic variation among the populations studied.