Voltage-dependent anion channels (VDACs1-3) are pore-forming proteins located in the outer mitochondrial membrane of various tissues and in human sperm flagella. VDACs are involved in metabolite fluxes between mitochondria and other cell compartments and play a role in the motility of mammalian spermatozoa. VDAC3-deficient male mice lacking exons 5-8 were reported to be healthy but infertile (Sampson , 2001). We analysed mutations in these exons of the human VDAC3 (hVDAC3) gene in spermatozoa of 32 asthenozoospermic patients. Previously, we reported on nucleotide substitution mutations in exon 6 (Asmarinah , 2005); now, we continue with the examination of exons 5, 7 and 8. Amplification of the exon fragments of the hVDAC3 gene was carried out by polymerase chain reaction (PCR) using specific primers for each exon followed by sequencing. We found various types of mutations in the examined exons of the hVDAC3 gene, such as deletion and nucleotide substitution in spermatozoa from seven of the 30 asthenozoospermic sperm samples (and unconfirmed insertions in two other ones) but none in spermatozoa from normozoospermic controls. Our preliminary data, although of small numbers investigated, suggest that genetic mutations in the hVDAC3 gene could be an explanation for the aetiology of infertility in these asthenozoospermic patients.
- Sperm motility