Comparison of cadherin and integrin localization in bovine cystic and healthy follicles

As stage progresses in the cystic follicle, granulosa cells are lost. We hypothesized that the granulosa and theca interna layers are detached in association with weakened expression of cell adhesion molecules such as cadherin (cellcell adhesion) and integrin (cellextracellular matrix adhesion) in cystic follicles. To elucidate this hypothesis, we immunolocalized these molecules in the granulosa and theca interna and compared them between cystic and small healthy follicles. Sections were immunostained with cadherin and integrin 1 antibodies and their localizations were compared. Cadherin-positive reaction was seen in the cytoplasma of all granulosa cells. No increase in the frequency of cadherin-positive area in the granulosa layers and the intensity of cadherin immunoreaction in the theca interna was detected in cystic follicles compared with healthy ones. A dense immunoreaction product of integrin 1 was detected in the theca interna in both cystic and healthy follicles. Intensity of integrin 1-immuno reaction in the granulosa layers and integrin 1-positive area in the theca interna was significantly lower in the cystic follicle than in the healthy follicles. These results suggest that granulosa and theca interna cells are detached while maintaining the cellcell adhesion, resulting in the consequent loss of these layers from the cystic follicle.