News Releases & Research Results Discovery of a key molecule regulating sperm maturation: A new perspective on the etiology and treatment of infertility

The results of a collaborative research conducted by Assistant Professor Daiji Kiyozumi and Professor Masahito Ikawa (concurrently serving as Specially Appointed Professor of the University of Tokyo Institute of Medical Science) of Osaka University Research Institute for Microbial Diseases and others.

• The research group succeeded in the world-first elucidation of the mechanism through which the testicular protein “NELL2” stimulates and induces the differentiation of the epididymis* and switches on sperm maturation in the process of sexual maturation.
  *An organ which encloses a single, tightly coiled tube of the epithelial tissue extending from the testis. The tube, which is thin in childhood, thickens associated with aging around the time when spermatogenesis occurs.
• In addition, they discovered that the “NELL2” protein plays a role in an inter-organ signaling system called “lumicrine” postulated more than 40 years ago.
• The results of this research should be applied to the development of a diagnostic/therapeutic drug for male infertility or a contraceptive, and to various studies in the field of life science as a new mechanism underlying inter-organ signaling.

This research project was conducted with the support of the Project for Elucidating and Controlling Mechanisms of Aging and Longevity by AMED.

The results of research were published in Science, an American scientific journal, on June 5.

Kiyozumi D., et al. NELL2-mediated lumicrine signaling through OVCH2 is required for male fertility Science
DOI：10.1126/science.aay5134