Distribution of α<inf>3</inf>, α<inf>5</inf> and α(v) integrin subunits in mature and immature human oocytes

The distribution of three integrin subunits, α3, α5 and α(v), in immature and mature human oocytes has been examined using immunofluorescence and confocal microscopy. The results demonstrate that both α5 and α(v) are present at the germinal vesicle stage, while α3 was only detected in oocytes after germinal vesicle breakdown, in metaphase I and II stage oocytes. The cortical concentration of integrin subunits α3 and α5 is consistent with their localization in the oolemma. In contrast, the homogeneous distribution of α(v) throughout the oocyte suggests the existence of cytoplasmic reservoirs of this protein in the oocyte.