A culture platform to reconstitute human foetal testes†

Human germ cells (hGCs) are specified early during development and migrate to the developing gonads. After sex determination, gonadogenesis and gametogenesis continue in a sex-specific manner, giving rise to testes in males and ovaries in females. In males, the relationship between hGCs and Sertoli cells in the seminiferous tubules remains largely unexplored. Here, we developed a culture platform using dissociated second trimester human fetal testes to reconstitute human testes (rhTestes). We investigated the effect of stress inhibitors and cell type ratio (Sertoli cells and testicular interstitial cells) during aggregation on the organisation of the rhTestes and the number of hGCs. Regardless of the organisation, we observed DDX4+ hGCs for at least two weeks in culture, concentrated at the periphery of rhTestes. This study established a 3D culture system for human fetal testes, contributing to ongoing efforts to investigate the interactions between different testicular cell types. Ultimately, this platform may contribute to gain insights in human male gametogenesis and to our understanding of male infertility.