Phylogenetic Study of Philippine Pigs (Sus scrofa L.) from Ifugao and Kalinga Based on Mitochondrial DNA D-loop Analysis

Abstract

Conservation genetic studies for Philippine pigs are essential to sustain global biodiversity. To study the phylogenetic relationship of Philippine pigs, 79 samples were collected from Ifugao (n = 41) and Kalinga (n = 38) provinces located in the Cordillera Administrative Region, northern Philippines. Mitochondrial DNA control region analysis was undertaken to investigate the phylogenetic relationship between the pig populations from the two provinces and other Asian and European pig breeds. Fourteen (14) haplotypes (H1–H14) were detected in the Ifugao and Kalinga samples. Several haplotypes – specifically, H1, H4, H9, H12, and H14 – formed an independent clade with the Type I Lanyu haplotypes, which are known to be unique in Taiwan pigs. The remaining haplotypes (H2, H3, H5–H8, H10, H11, and H13) clustered with the haplotypes of other Asian pig breeds within the major Asian clade. These results suggest the close relationship between Kalinga and Ifugao pigs and Type I Lanyu pigs. The existence of duplicate motifs also revealed that the native pigs from Ifugao and Kalinga belong to a distinct genetic lineage that clustered with other Philippine pig samples and separate from other Asian pigs, whereas the other samples may represent a recent introgression of modern lineages.