Theca cell : The flattened stroma cells forming a sheath or theca outside the basal lamina lining the mature ovarian follicle. Thecal interstitial or stromal cells are steroidogenic, and produce primarily androgens which serve as precursors of estrogens in the granulosa cells.

Alkaline phosphatase (AP)

• used as a marker of theca-derived lutein cells. PMID: 8452642

BMP-4

• bovine theca interna cells in primary culture express several type-I and type-II receptors for bone morphogenetic proteins (BMPs). PMID: 15625241

CYP17

• a theca cell marker. PMID: 11014238

NR5A1 (steroidogenic factor-1, SF-1)

• a master regulator of tissue-specific gene expression in reproductive and steroidogenic tissues. The role of the NR5A1 activating functions AF-1 and AF-2 was studied in primary bovine theca cells. PMID: 17176485