Wrapped up and protected with just their tails protruding, nearly-mature sperm or spermatids complete their final stages of development. Deep within the testis, in seminiferous tubules, the developing spermatids remain embedded within the lining of Sertoli cells which ‘nurse’ them through to maturity. The Sertoli cells (foreground) secrete a variety of hormones and other signalling molecules that direct and regulate sperm development. And they consume excess cell debris generated during the division and maturation of sperm. Concerned about decreasing fertility rates, researchers are studying this close interaction between Sertoli cells and spermatids to understand the complexities of sperm production and why it sometimes goes wrong – like it did for the mutant two-tailed specimen in green.
Written by Edwin Colyer
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