The Anatomy and Ultrastructure of the Rete System in the Fetal Mouse Ovary

Abstract

The rete system of the 12.5-day-old fetal mouse ovary has been described. The rete system is divided into three parts: 1) the extraovarian rete lying in the periovarian tissue, which consists of mesonephric tubules and cords; 2) the connecting rete at the cranial basal area of the ovary, which is composed of a labyrinth of cell cords, which connects the extraovarian rete to the ovary; 3) the intraovarian rete within the ovary, which develops cell cords which are associated with the connecting rete. The ultrastructural similarities of all rete cells indicate their common origin. A unique cytoplasmic component, the “dense rete bodies,” was present only in rete cells and was therefore used as a marker for these cells. Cytoplasmic protrusions of the intraovarian rete cells containing “dense rete bodies” are often in contact with germ cells. The fact that the majority of the somatic cells in the cranial basal part of the ovary are rete cells supports the idea of previous studies that