Mitochondrial morphology during preimplantational human embryogenesis

Abstract

The structure, distribution, and function of mitochondria during human oogenesis and early development is reported. Oogonia show a sparse and even distribution of mitochondria, which are oval or elongated. Except around nuclei, growing oocytes from small antral follicles have more dense roun-ded or oval mitochondria, associated with the rough endoplastic reticulum. Mitochon-dria in fully grown, germinal vesicle (GV) oocytes present an inert appearance, with a dense matrix and a few arch-like or transverse cristae. At this stage mitochon-dria are usually absent from the cortical part of the cytoplasm. Mitochondria i