The phrase "seminiferous tubules" refers to tiny tubes found in the testicles of males. These tubules are responsible for producing and carrying sperm cells. Full definition
Males from extinct lines had high variability in reproductive organ size, low sperm counts, low sperm motility, and a high rate of vacuolization of seminiferous tubules. (genetics.org)
After 20 years developing their method, they say they can turn the progenitor cells that are inside seminiferous tubules, called spermatogonia, into mature sperm. (newscientist.com)
Philippe Durand and Marie - Hélène Perrard at the biotechnology company Kallistem in Lyon, France, say that their method coaxes seminiferous tubules — tissue that produces sperm in the testes — taken from humans, rats or monkeys into producing mature sperm cells. (newscientist.com)