A comparison of oocyte organelles in Monodelphis domestica with those of other marsupials and eutherians.

This paper reviews the current knowledge of oocyte cytology in marsupials, particularly Monodelphis domestica, and eutherian mammals. Some of the conspicuous features will be described and their function discussed. Despite many fundamental similarities between the oocytes of eutherian mammals and marsupials, some aspects are different (e.g. growth pattern, final size, timetable of cytoplasmic maturation and utilization of storage material during early cleavage stages), when most of the vesicles are extruded into the perivitelline space in marsupials.