In this study we test the theory that the presence of the conserved vertebrate telomeric sequence (T 2AG 3) n at the centromeres of Australian marsupial 2n = 14 complements is evidence that these karyotypes are recently derived, which is contrary to the generally held view that the 2n = 14 karyotype is ancestral for Australasian and American marsupials. Here we compare the distribution of the (T 2AG 3) n sequence and constitutive heterochromatin in the presumed ancestral 2n = 14 complement and in complements with known rearrangements. We found that where there were moderate to large amounts of constitutive heterochromatin, the distribution of the (T 2AG 3) n sequence reflected its presence as a native component of satellite DNA rather than its involvement in past rearrangements. The presence of centromeric heterochromatin in all Australian 2n = 14 complements therefore suggests that centromeric sites of the (T 2AG 3) n sequence do not represent evidence for recent rearrangements.
|Number of pages||10|
|Publication status||Published - 2004|
- fluorescence in-situ hybridization