In-vitro maturation of round spermatids using co-culture on Vero cells

In an attempt to determine whether co-culture could promote sperm maturatio n, three patients with nonobstructive azoospermia, two with maturation arre st at the level of primary spermatocytes and one patient with <1% tubules s howing complete spermatogenesis, and one patient with total globozoospermia , gave consent to experimentally co-culture round spermatids retrieved from the testicle on Vero cell monolayers. In all azoospermic patients elongati ng spermatids could be obtained from round spermatids. In one case of matur ation arrest, of 37 round spermatids cocultured for up to 5 days, 30% devel oped flagella, 46% matured to elongating and 19% to elongated spermatids, w ith one mature spermatozoon also obtained (3%). In the same patient, primar y cultures of three round spermatids with flagella enabled development of o ne further mature spermatozoon. In the case with total globozoospermia, of six round spermatids co-cultured for up to 5 days, one mature spermatozoon was obtained, with a flagellum and normal head morphology. These preliminar y findings suggest that it may be possible to overcome the round spermatid block, and even the triggering of morphological abnormalities arising at th e spermiogenic level, by in-vitro maturation under special environmental co nditions.