Comparison of chromosomal distribution of a retroposon (LINE) and a retrovirus-like element mys in Peromyscus maniculatus and P. leucopus.

Chromosomal distribution for two interspersed elements (LINEs and mys) that are thought to have established their chromosomal position primarily by transposition was compared between two species of deer mice (Peromyscus leucopus and P. maniculatus). Both LINEs and mys generally produced an autosomal banding pattern reflective of G-bands and both hybridized preferentially to the sex chromosomes. The pattern on the long arm of the X was unique for each, with mys reflecting the G-bands (four bands with the telomeric most prominent) and LINE producing five equally spaced bands of equal intensity. LINE also preferentially hybridized to the short arm of the longest autosomal pair. Some aspects of these patterns are explained adequately with proposed mechanisms that would produce a non-random pattern of chromosomal distribution (i.e. both reflect autosomal G-bands and both preferentially insert into AT-rich regions characteristic of G-bands). However, other aspects such as the differences observed on the long arm of the X do not appear to fit any predictions of proposed mechanisms.