Genetic diversity of grasscutter (Thryonomys swinderianus, Rodentia, Hystricomorpha) in Ghana based on microsatellite markers

Grasscutter (Thryonomys swinderianus) is a fairly large rodent that inhabits sub-Saharan Africa. There are very limited ecological studies on the grasscutter despite its importance as a protein resource. The objective of this study was to apply novel microsatellite markers to determine the genetic structure and diversity of grasscutter populations in Ghana. A total of 66 hair samples were collected from grasscutters in three main agro-ecological zones of Ghana, namely Guinea Savanna (n = 19), Forest (n = 16) and Coastal Savanna (n = 16) as well as Volta Region (n = 15). Samples were genotyped at 12 polymorphic loci and the results showed relatively high diversity (MNA = 7.3, HE = 0.745) within populations. Phylogenetic analysis revealed that Forest population is closer to the Coastal Savanna population than the other populations whilst Volta Region population is closer to the Guinea Savanna population than the other populations. Pairwise FST values however indicated that all populations were significantly differentiated (p < 0.01). STRUCTURE clustering analysis showed that Volta population split from the Guinea Savanna population. Grasscutter populations in Ghana are genetically differentiated according to agro-ecological zones and the Volta Lake could be serving as a barrier to gene flow

Genetic diversity of some Ghanaian pigs based on microsatellite markers

A knowledge of the level of genetic diversity is very important in ensuring the sustainable utilisation of animal genetic resources. To this end, the genetic diversity of some local pigswas assessed by genotyping 86 unrelated pigs in four regions of Ghana namely Northern (Tingoli = 9), Upper West (Papu = 31 and Babile = 32) and Upper East (Gia = 14) using 12 microsatellite markers.The number of alleles (Na), number of effective alleles (Ne), observed heterozygosity (Ho), expected heterozygosity (He) and inbreeding coefficient (FIS) were used to assess the level of genetic differentiation among the five populations in this study. All loci studied were polymorphic and the mean number of alleles ranged from 4.58 (Yorkshire) to 10.58 (Papu) with an overall average of 7.65 alleles. At all the 12 loci studied, inbreeding coefficient (FIS) deviated significantly from zero with a mean of 0.32. When the Nei’s standard genetic distance based on the proportions of shared alleles was used to construct a neighbour joining tree, pigs from the different communities sampled in the Upper West region emerged with the highest bootstrap value of 90%. Generally, the sampled pigs represent distinct populations with a moderate amount (12%) of genetic differentiation but considerable amount of inbreeding (29%) has taken place within these populations over the years. This is the first report of the genetic diversity of Ghanaian local pigs using microsatellite markers