Analysis of chromosomal equipment and DNA fragmentation in spermatozoa of infertile men
Among 10 to 15% of couples with infertility problems, etiology is masculine in half of the cases. The presence of a constitutional chromosomal abnormality, or a genetic abnormality (microdeletions of chromosome Y, mutations in Aurora Kinase c -AURKc-) or DNA sperm fragmentation could be one of the causes of infertility. This work has consisted in studying, by FISH (Fluorescent in situ Hybridization), the chromosomal equipment of gametes of infertile men having a normal lymphocytic karyotype or not and the rate of sperm DNA fragmentation in these patients, by TUNEL (Terminal Uridine Nick-end Labeling). Otherwise, we have developed techniques to detect the presence of microdeletions on chromosome Y and mutations of AURKc. In patients with teratozoospermia, the rate of unbalanced gametes ranges from 0.47% to 100%. Moreover, they have a fragmentation rate 12 times higher than controls (14.6% versus 1.2%). In patients with a constitutional structural abnormality, the analysis of meiotic segregation indicates that the rate of chromosomal unbalanced gametes varies from 0% to 65.60% in function of the structural abnormality (balanced reciprocal translocation, robertsonian translocation or pericentric inversion). Their percentage of fragmentation DNA sperm is between 1% and 27%. The unbalanced gametes have more fragmented DNA than normal/balanced gametes. The studies of meiotic segregation and DNA fragmentation are complementary in exploration of male infertility.