The Zebrafish in Toxicology/Granulosa cells

Reproduction - Ovary edit

Normal Histology edit

Granulosa cells edit

Oocytes are lined by two layers, an internal granulosa cell layer and an external theca layer.

The granulosa cell layer develops gradually with the growing oocyte. Early previtellogenic oocytes are accompanied by flat epithelial granulosa cells [red arrowhead], granulosa cells with larger oocytes [blue arrowheads] have a higher appearance.

The theca cell layer is composed of stroma cells [green arrowheads] and contains capillaries [c]. The theca layer is continuous [black arrowheads] over neighbouring oocytes.

Note radial striation in the zona radiata [zr] of large vitellogenic oocytes.


Adult female zebrafish, H&E staining