Life Without Tails

Men with azoospermia – the absence (or extremely low levels) of sperm in semen – are considered infertile. And those wanting a baby are recommended to use a sperm donor during fertility treatments. However, some men with this condition do have round spermatids – cells arrested at a stage that normally would undergo further events to become mature sperm. Researchers were able to identify these round spermatids and injected them using a procedure called round spermatid injection (ROSI) into an egg cell from the man’s partner, which had been stimulated with an electric current. Pictured is the sequence of development of the fertilised egg before implantation in the partner’s uterus (from top left to bottom right). Twelve women involved in the study gave birth to a total of 14 healthy babies, showing that ROSI could enable men whose sperm don’t develop past a certain stage to have their biological child.

Written by Katie Panteli

Katie Panteli

Writer

Katie, a Warwick Biomed graduate, works for a science-publishing house in London with some of the world's most respected scientific minds. She's most interested in human biology, anything and everything that makes us tick.

• Image from work by Atsushi Tanaka and colleagues
• Saint Mother Obstetrics and Gynecology Clinic, Japan and Department of Anatomy, Physiology, and Biochemistry, University of Hawaii Medical School, Honolulu
• Image copyright held by original authors; image reproduction permitted by PNAS
• Published in PNAS, November 2015