Restriction fragment length variants in the marsupial Sminthopsis crassicaudata

A fully pedigreed colony of the dasyurid marsupial Sminthopsis crassicaudata has provided material for establishing two panels of DNA samples: a broadbased test panel and a two-generation family panel. These have been used to search for genetic markers in the form of restriction fragment length variants. The molecular probes--pSG-2H, a region of the S. crassicaudata embryonic beta-globin gene; pB8.BS, a region of the human ubiquitin gene, and p3-21a1:1, a region of the processed pseudogene of phosphoglycerate kinase-1 of the macropodid marsupial Macropus robustus--were hybridized to Southern blots of EcoR1-digested DNA from the panels. Analysis of these blots when probed with pSG-2H provided evidence of two alleles segregating at a single EcoR1 site. Analysis of the same blots when probed with pB8.BS suggested allelic variation at two closely linked EcoR1 sites. Probing the blots with p3-21a1:1 produced a complex pattern of bands resembling DNA fingerprints. The presence of a 12.3-kb band was found to conform to a simple autosomal dominant mode of inheritance. Analysis of the family data, for each probe, revealed no significant departure from Mendelian inheritance. This work has provided additional genetic markers that will enhance the use of S. crassicaudata as a model marsupial species and has demonstrated that a high level of genetic variability has been maintained in the marsupial colony.