A COMPARISON OF OOCYTE ORGANELLES IN MONODELPHIS-DOMESTICA WITH THOSEOF OTHER MARSUPIALS AND EUTHERIANS

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