RESUMO
INTRODUCTION: Neonatal testicular germ cells/gonocytes, transform into stem cells for spermatogenesis during 'minipuberty', driving change in timing of surgery. This study examined gonocyte transformation in cryptorchid testes in children ≤18â¯months of age with unilateral, bilateral undescended testes (UDT), complete or partial androgen insensitivity syndrome (CAIS, PAIS) [3,4]. MATERIAL AND METHODS: Testicular biopsies were taken from patients with unilateral or bilateral UDT, PAIS or CAIS, aged 10â¯days-18â¯months. These testicular sections underwent immunohistochemistry with antibodies (Oct4, Ki67, C-Kit, Sox9) followed by confocal imaging, cell counting and statistical analysis. RESULTS: Both Sertoli cells/tubule and germ cells (GC)/tubule decreased with age, and % empty tubules (no GC) increased with age but with no significant differences between patient groups. Oct4+ germ cells/tubule decreased with age. There are some GCs and Sertoli cells proliferating during the first year and most proliferating Oct4+ germ cells (Oct4+/Ki67+) were located off tubular basement membrane. CONCLUSION: Our study showed that Oct4 expression gradually decreased after minipuberty and transformation into spermatogonia. Germ cells and Sertoli cells undergo mitosis during the first 12â¯months although not abundantly. We propose that Oct4+ gonocyte transformation into spermatogonia via proliferation and migration to the basement membrane may be delayed in UDT.