Genetic analysis of Croatian autochthonous pig breeds based on microsatellite markers

Black Slavonian pig (BS) and Turopolje pig (TP) are two Croatian autochthonous pig breeds. At the beginning of this century attempts were made to preserve and re-establish them, which included also employment of the genetic methods for studying genetic characteristics of both breeds. The number of Black Slavonian breed sows was increased from 237 in 2001 to 1305 last year, while the number of Turopolje breed sows rose from 45 to 132 in the same period. A set of 18 microsatellite markers was used to genotype 20 BS pigs, 20 TP pigs and 20 wild boars. The basic statistical analysis included number of samples, number of alleles for each locus, expected and observed heterozygosity, FIS and their statistical significance FISsign. In observed populations, a relatively high variety of loci was present. Average heterozygosity was between 0.35 and 0.64. The average fixation index (FST) was 0.24. Multilocus FST values indicated that around 24% of the total genetic variation was explained by population differences, with the remaining 78% corresponding to differences among individuals within population. Genetic distances between populations were made with PCA method and it was noticed that studied populations are clearly defined. The analysis of population structure indicates no admixture among analysed breeds. However, some substructuring in the Black Slavonian pig population was observed. Results confirmed usefulness of microsatellites for studying genetic diversity among Croatian autochthonous pig breeds, but for obtaining more accurate results, a study involving larger number of animals and other related breeds would be required.