A population of sperm progenitor cells, known as Asingle spermatogonia, has been described in mammalian testes, but these cells have not been studied in bat testes. Bats are a good model due to their human-like reproductive characteristics. The results show the existence of spermatogonial stem cells that constantly renew spermatogenesis in these chiropterans, similar to that described in other mammals such as humans. Image by Tania Porras-Gómez and Norma Moreno-Mendoza.

In recent years, the COVID-19 pandemic has been considered a threat to human health. The SARS-CoV-2 virus has caused various disorders in the body’s systems and the reproductive system is no exception. Based on the result of present study, COVID-19 infection increases the oxidative stress and reduces the semen quality, thus reducing the fertility potential. Illustration by Sareh Karimi.

Testicular organoids (TOs) represent a groundbreaking avenue captivating researchers seeking to understand and restore fertility. While TOs hold remarkable potential, their journey to replicate human spermatogenesis within a laboratory environment remains elusive. This review navigates the landscape of TOs, unveiling their unparalleled potential while dissecting the challenges hindering their success, helping refine these models for transformative clinical applications. Photograph by K. Coward..

This article belongs to the Collection Dedication to Jim Cummins.