Mitochondrial DNA control region of the endangered Busok cat (Felis catus) from Ra’as Island, Indonesia

Abstract The domestic cat originated in the Near East and dispersed along human trade routes, and its mitochondrial control region is used to trace this spread. Island populations are informative as each founding event samples only a portion of the source gene pool. However, relatively few island populations have had genetic evaluations. The Busok cat, a blue-gray, short-tailed landrace from Ra’as Island, Indonesia, was recognized in 2022 with a defined phenotypic breed standard. It is now traded outside the island, but fewer than 100 phenotypically pure individuals are known, and no genetic data exist. We sequenced the mitochondrial control region of three Busok cats and one non-Busok blue-gray cat from West Java, analyzing a 349 bp segment on both strands, and compared them with 66 reference sequences from six countries, the A–L mitotype panel, and two wild felid outgroups. The three Busok cats carried two maternal haplotypes, mitotypes A and B, both common in domestic cats worldwide. The West Javan cat had mitotype B and was identical to one Busok cat. Two distinct lineages among the three cats suggest at least two founding dams, although the haplotype diversity cannot be accurately assessed due to the small sample size. Both lineages grouped within broad cosmopolitan clusters. Our data indicate that the Busok cat lacks a unique maternal lineage, consistent with human-assisted dispersal from a global gene pool. We present the first maternal DNA reference for this breed, and nuclear and phenotypic markers could further clarify its origin.