Now in our 13th year of bringing you beautiful imagery from biomedical science every day

Search the archive of over 4000 images

Fertile Discussion

How testis-epididymis communication leads to fertile sperm

21 July 2020

Fertile Discussion

Made in the testes, sperm have a long journey ahead before emerging with the ability to fertilise an egg. From each testis’ seminiferous tubules, they travel to the epididymis, a long tightly-coiled tube where they continue to mature, before exiting through the vas deferens towards the ejaculatory ducts. A functional epididymis is critical to male fertility, and researchers recently discovered that this depends on communication with the testes during development. They identified a testicular protein, NELL2, which binds to a specific receptor in the developing epididymis, eventually unlocking production of the enzyme OVCH2 (in magenta in this slice through the epididymis), whose later interactions with a sperm surface protein, ADAM3, are essential for sperm maturation. Male mice lacking NELL2 are infertile, suffering from defects in sperm motility, suggesting that these complex interactions between testis and epididymis, known as lumicrine signalling, have major implications for research into male infertility.

Written by Emmanuelle Briolat

Search The Archive

Submit An Image

Follow on Tumblr

Follow on Instagram

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.