Marsupial Chromosome Evolution

Abstract

Marsupial chromosomes were among the first mammalian chromosomes to be studied in the early twentieth century and have since been exten- sively characterised by multiple approaches. With relatively few and large chromosomes, marsupi- als have proven to be ideal subjects for studying how chromosomes have changed during marsupial evolution from a predicted ancestral marsupial karyotype consisting of just seven pairs of chromo- somes. In this article, the current understanding of marsupial chromosome evolution is reviewed and the way two families of marsupials with different rates of chromosome evolution help to decipher the mechanisms involved in chromosome evolution is discussed. The family Dasyuridae is characterised by remarkable chromosome stability, whereas the family Macropodidae has experienced extensive chromosome shuffling. Comparisons of the differ- ences in chromosome features between these two families may hold the key to understanding the role of chromosome rearrangements in speciation.