Distribution of α3, α5 and αv integrin subunits in mature and immature human oocytes

The distribution of three integrin subunits, alpha(3) alpha(5) and alpha(v) in immature and mature human oocytes has been examined using immunofluorescence and confocal microscopy. The results demonstrate that both alpha(5) and alpha(v) are present at the germinal vesicle stage, while alpha(3) was only detected in oocytes after germinal vesicle breakdown, in metaphase I and II stage oocytes. The cortical concentration of integrin subunits alpha(3) and alpha(5) is consistent with their localization in the oolemma. In contrast, the homogeneous distribution of alpha(v) hroughout the oocyte suggests the existence of cytoplasmic reservoirs of this protein in the oocyte.