Molecular studies on the colonization of the Madeiran archipelago by housemice

To study the colonization history of the house mouse (Mus musculus domestic us) on the Madeiran archipelago, complete mitochondrial D-loop sequences we re obtained for 44 individuals from Madeira, Porto Santo and Ilhas Desertas . Altogether, 19 D-loop haplotypes were identified which formed part of a s ingle clade in a phylogeny incorporating haplotypes from elsewhere in the r ange of M. m. domesticus, indicating that the Madeiras were colonized from a single source. Similarities between the sequences found in the Madeiras a nd those in Scandinavia and northern Germany suggest that northern Europe w as the source area, and there is the intriguing possibility that the Viking s may have accidentally brought house mice to the archipelago. However, the re is no record of Vikings visiting the Madeiras; on historical grounds, Po rtugal is the most likely source area for Madeiran mice and further molecul ar data from Portugal are needed to rule out that possibility.