Integrins are transmembrane receptors expressed in all nucleated mammalian cells, critically involved in cell-matrix adhesion and cell-cell interactions that modulate many signalling cascades. It is assumed that integrins also provide essential functions of the reproductive system. In this study, we describe the detailed localization and distribution of αV integrin in the plasma membrane of bull sperm head and tail. Integrin αV was observed in the area of forming acrosome in developing sperm since the stage of round spermatids and persists in the acrosome during epididymal maturation and ejaculation till the acrosomal exocytosis. We detected CD9 and CD81 tetraspanins as the potential partners of αV integrin. Their similar staining pattern in testicular tissue suggested the involvement of these molecules in the tetraspanin web of "testisomes". Moreover, the complex of αV with β1 and β3 integrin subunits cannot be excluded at least in sperm. The presented findings contribute to understanding the mutual action of integrins and tetraspanins during sperm development and maturation.

Group of Reproductive Biology Institute of Biotechnology Czech Academy of Sciences v v i BIOCEV Průmyslová 595 252 50 Vestec Czech Republic; Department of Biochemistry Faculty of Science Charles University Hlavova 8 128 40 Prague 2 Czech Republic

Laboratory of Reproductive Physiology Institute of Animal Biochemistry and Genetics Centre of Biosciences Slovak Academy of Sciences v v i Dúbravská cesta 9 840 05 Bratislava Slovak Republic

References provided by Crossref.org