Gene mapping in marsupials and monotremes

Abstract
Somatic cell hybrids have been obtained between HPRT Chinese hamster cells and cells from several dasyurid marsupial species. These hybrids show the extensive loss of marsupial chromosomes characteristic of the majority of marsupial-eutherian somatic cell hybrids. Although all of the hybrids expressed the selected marsupial marker, HPRT, the only other markers observed were PGK, GLA, and G6PD, consistent with the conservation of X-linked genes extending to this major group of marsupials. Counterselection confirmed the synteny of PGK and GLA with HPRT, whereas G6PD showed decreased concordance.