MUS-SPRETUS LINE-1S IN THE MUS-MUSCULUS-DOMESTICUS INBRED STRAIN C57BL 6J ARE FROM 2 DIFFERENT MUS-SPRETUS LINE-1 SUBFAMILIES/

A LINE-1 element, L1C105, was found in the Mus musculus domesticus inb red strain, C57BL/6J. Upon sequencing, this element was found to belon g to a M. spretus LINE-1 subfamily originating within the last 0.2 mil lion years. This is the second spretus-specific LINE-1 subfamily found to be represented in C57BL/6J. Although it is unclear how these M. sp retus LINE-1s transferred from M. spretus to M. m. domesticus, it is n ow clear that at least two different spretus LINE-1 sequences have rec ently transferred. The limited divergence between the C57BL/6J spretus -like LINE-1s and their closest spretus ancestors suggests that the tr ansfer did not involve an exceptionally long lineage of sequential tra nspositions.