Figure (IMAGE) Osaka University Caption Epididymis (magenta) responding to the protein NICOL coming from the testis. Under the influence of NICOL, spermatozoa, which can be recognized by nuclear staining inside the lumen, become mature and fully fertile. Credit Daiji Kiyozumi Usage Restrictions Credit must be given to the creator. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.