Developmental exposure to a real-life environmental chemical mixture alters testicular transcription factor expression in neonatal and pre-pubertal rams, with morphological changes persisting into adulthood.

Environmental chemical (EC) exposure may be impacting male reproductive health. The translationally relevant biosolids treated pasture (BTP) sheep model was used to investigate gestational low-level EC mixture exposure on the testes of F1 male offspring. Adult rams from ewes exposed to BTP 1 month before and throughout pregnancy had more seminiferous tubules with degeneration and depletion of elongating spermatids, indicating possible "recovery" from previously reported testicular dysgenesis syndrome-like phenotype in neonatal and pre-pubertal BTP lambs. Expression of transcription factors CREB1 (neonatal) and BCL11A and FOXP2 (pre-pubertal) were significantly higher in the BTP exposed testes, with no changes seen in adults. Increased CREB1 , which is crucial for testes development and regulation of steroidogenic enzymes, could be an adaptive response to gestational EC exposure to facilitate the phenotypic recovery. Overall, this demonstrates that testicular effects from gestational exposure to low-level mixtures of ECs can last into adulthood, potentially impacting fertility and fecundity. • Testis development affected by gestational environmental chemical mixture exposure. • Adult phenotypic "recovery" from TDS-like phenotype in neonatal and pre-pubertal. • mTOR signalling a repeat finding in foetal, neonatal, pre-pubertal and adult testes. • HIF1α activation highest in neonatal, then pre-pubertal, but absent in adult testes. • Higher testes expression of CREB1 (neonatal) and BCL11A and FOXP2 (pre-pubertal). [ABSTRACT FROM AUTHOR]