Research On Genetic Recombination Through Meiosis In Spermatocytes Of The Non-obstructive Azoospermic Patients

Aim: To Investigate the genetic mechanism of meiosis in male spermatocytes of NOA patients.To discuss the pathogenesis of infertility patients with a special chromosome phenotype.To provide new theoretical basis for clinical diagnosis,treatment and genetic counseling of this type of patients.Method: We selected three groups of patients: the normal-karyotype group,the translocation carriers group and the pericentric inversion group.After the testicular sperm extraction,store the removed testicular samples in PBS at zero degrees Celsius.The removed testicular samples were sent to the laboratory within 30 minutes.The spermatocyte synaptonemal complex was prepared by spreading method and visualized by immunofluorescente staining that used SCP3 antibody,MLH1 antibody and CREST antiserum to mark the lateral elements of synaptonemal complex,the recombination sites and the centromere protein.In the normal-karyotype group,105 pachytene spermatocytes were obtained.In the translocation carriers group,86 pachytene spermatocytes were obtained.And in the pericentric inversion group,89 pachytene spermatocytes were obtained.Then we do some statistical analysis on the data related to the MLH1.Result: The average number of recombination sites in the cells of the normal-karyotype group was 48.88±6.287.The average number of recombination sites in the cells of the translocation carriers group was 43.45±6.916.The average number of recombination sites in the cells of the pericentric inversion group was 40.72±7.431.The average number of recombination sites in the cells of the translocation carriers group and the pericentric inversion group was significantly less than the recombination sites in the cells of the normal-karyotype group(p<0.05).The XY chromosome of the translocation carriers group and the pericentric inversion group had a lower frequency of recombination sites than the XY chromosome of the normal-karyotype group(p<0.05).Meanwhile,a higher frequency of SCs without recombination sites was found in these patients compared with the control group(p<0.05).Conclusion: The decline of recombination frequency and the reduction of synopsis during meiotic prophase is an important factor in spermatogenesis obstruction.