Phylogenetic studies of marsupials based on phosphoglycerate kinase DNA sequences

Phosphoglycerate kinase sequences were obtained for 313 aligned bases of 41 individuals from 39 marsupial species. In contrast to previous molecular a nalyses, the relationships suggested by these data show a high level of con gruence with morphologically defined orders and families. Four main monophy letic lineages are recognizable. These are the monogeneric orders Microbiot heria (Dromiciops australis) and Notoryctemorphia (Notoryctes typhlops), a grouping of the American orders Didelphimorphia and Paucituberculata, and t he Australasian species other than N. typhlops. Within the Australasian lin eage, there are again four main monophyletic groups; the Dasyuridae, two pe ramelemorph (bandicoot) lineages (one comprised of pseudogene sequences) an d the Diprotodontia. This topology is not greatly affected by the exclusion of pseudogenes except that a clade of syndactylous species (Peramelemorphi a plus Diprotodontia) is recovered. Two other peramelemorph pseudogenes hav e inserts of about 1 kb with high levels of similarity to LINE 1 elements. The Diprotodontia is notable for its relative lack of intersequence variati on in comparison to the Dasyuromorphia. (C) 1999 Academic Press.