Y Chromosome mosaicism in pouch young of the marsupial,greater glider (Marsupialia: Petauridae)

Y chromosome elimination was studied in three tissues from 13 pouch young greater gliders. There was no sex chromosome loss from the liver, spleen or bone marrow of female pouch young ranging in age from approximately 4 to 80 days. All liver cells in a 15 day old male were XY but only 75 to 80% of the cells were found to be XY in older pouch young. The Y chromosome was eliminated from a higher percentage of spleen cells, with 45 to 50% of the cells retaining the Y chromosome in 60-100 day old animals. — Y chromosome elimination in greater gliders appears to most closely resemble the X and Y chromosome elimination system of the marsupial bandicoots. There are no clear resemblances to the kinds of sex chromosome elimination which occur in eutherian mammals.