An acute exposure to glyphosate-based herbicide alters aromatase levels in testis and sperm nuclear quality

•We investigated the effects of a glyphosate-based herbicide after an 8-day exposure of adult rats.•We have shown a significant and differential expression of aromatase in testis.•We have observed a diminution of mRNA expression of nuclear markers in spermatozoa.•These results suggest changes in androgen/estrogen balance and in sperm nuclear quality.•The repetition of exposures of this herbicide could alter the mammalian reproduction.

Roundup is the major pesticide used in agriculture worldwide; it is a glyphosate-based herbicide. Its molecular effects are studied following an acute exposure (0.5%) of fifteen 60-day-old male rats during an 8-day period. Endocrine (aromatase, estrogen and androgen receptors, Gper1 in testicular and sperm mRNAs) and testicular functions (organ weights, sperm parameters and expression of the blood–testis barrier markers) were monitored at days 68, 87, and 122 after treatment, spermiogenesis and spermatogenesis. The major disruption is an increase of aromatase mRNA levels at least by 50% in treated rats at all times, as well as the aromatase protein. We have also shown a similar increase of Gper1 expression at day 122 and a light modification of BTB markers. A rise of abnormal sperm morphology and a decrease of the expression of protamine 1 and histone 1 testicular in epididymal sperm are observed despite a normal sperm concentration and motility.