Ultrastructural studies on the morula in cattle.

Abstract

Embryos at morula stage were ultrastructurally examined. Blastomeres of normal embryos are characterized by the presence of ribosomes, short single and branched cisterns of endoplasmic reticulum, small spherical mitochondria and vacuolar-granular structures. An enhanced autophagy and the presence of numerous and large lipid droplets are signs of the beginning degeneration.