MEIOTIC MATURATION AND THE CORTICAL GRANULE REACTION IN STARFISH EGGS

¹ Department of Anatomy, University of Iowa, Iowa City, IA 52242., The Marine Biological Laboratory, Woods Hole, MA 02543
² Department of Population Dynamics, John Hopkins School of Hygiene, Baltimore MD 21205., The Marine Biological Laboratory, Woods Hole, MA 02543

Univ. of Iowa

Correlative light and electron microscopic studies of immature and maturing starfish (Asterias forbesi) eggs have been carried out demonstrating(l) morphological alterations attending meiotic maturation induced by 1-methyladenine and (2) the structure of the egg cortex and cortical granule reaction. Because cortical granule components, are structurally recognizable, their fate and relation to the development of the fertilization membrane could be determined. One and possibly more of the cortical granule components become an integral part of the fertilization membrane. Comparison of maturing and immature ova indicate that germinal vesicle-containing oocytes (immature) are capable of undergoing a cortical granule reaction morphologically similar to that of eggs having undergone germinal vesicle breakdown (maturing).