Graft Efficiency of Co-Cliitured Spermatogonial Cells Using Sperm Assay in Epididymal Lumen of Recipient Mice

Introduction: transplantation of germ cells restores the male fertility.nevertheless, a lot of questions remain incompletely resolved. the aim ofthis study was to evaluate in vitro colonization efficiency of germ cells andsperm production capacity of spermatogonial cells before and after cultureby sperm number assay in epididymis of recipient mice.material and methods: we developed a sertoli cell feeder in a co-culturesystem with spermatogonial cells and the cells were co-cultured for 2 months.the cells were isolated from mouse neonates. colony assay was performedduring culture using light microscopy. the transplanted cells were tracedusing brdu incorporation. sperm parameters were assessed 2 months aftertransplantation.results: our findings showed that spermatogonial cells created coloniesduring culture. transplantation of fresh spermatogonial cells at aconcentration of 2x10^5 cells/ml did not show significant differences.however, after transplantation of 2x10^5 cells/ml cultured for 2 weeks, thenumber of epididymal sperms in recipients increased significantly in groupswith more fresh cells.conclusion: epididymal sperm number in recipient mice can be increasedbyenrichment of type a spermatogonial cells using an in vitro co-culturesystem. other important factors include the source of donor cells and thenumber of transplanted cells.