Embryos resulting from oosyGM47 germ-line clones or laid by oosyGM73/oosyGM47 mothers have reduced numbers of germ cells compared to wild-type embryos. In cleavage stage embryos laid by oosyGM47/oosyGM73 mothers, axial expansion and nuclear migration to the cortex are disrupted and the synchrony of the divisions is disturbed.