New genetic data suggest ancient colonization of southern Italian islands by the western European house mouse Mus musculus domesticus

This study investigates the colonization patterns of the western European house mouse (Mus musculus domesticus) across five Italian islands using the mitochondrial D-loop marker. Samples from Sicily, Pantelleria, Ventotene, San Domino, and San Nicola were analyzed and assigned to one of 11 previously identified D-loop haplogroups, with seven found in the study area. Sicily, with five haplogroups, appears to be the centre of mitochondrial genetic diversity, likely due to various civilizations introducing mice since the Iron Age. In contrast, smaller islands like Pantelleria, San Domino, and San Nicola each have a single haplogroup, suggesting recent single founder events. Ventotene, despite its small size, hosts two haplogroups not found on mainland Italy, implying two separate ancient colonization waves. The results highlight a complex pattern of human-mediated colonizations from diverse source areas.