Short-term effects of estradiol and bisphenol A on gene expression associated with early head mineralization in the seabass Dicentrarchus labrax

Introduction Natural and synthetic estrogens are pollutants found in aquatic ecosystems at low concentrations reaching ng.L -1 to μg.L . At these concentrations, they able interfere with the fish endocrine system. When waterborne exposure occurs early life stages, when blood low, this may have significant consequences for estrogen-sensitive functions such as skeletal development. Methods To better understand how (xeno)estrogens affect head mineralization, 12 days post-hatch larvae of European seabass Dicentrarchus labrax were experimentally exposed 4 natural estrogen estradiol E2 xenoestrogen bisphenol A (BPA), both used either regulatory concentration water quality or a 100 times higher concentration. Head mineralization level was assessed using Alizarin red staining, together relative quantification mRNA expression levels several genes playing key roles skeletogenesis signaling pathways. Results We showed that (xeno)estrogen larval stage increases skeleton-associated genes: matrix proteins encoding ( col1a2 , col2a1a col2a1b bgp1a bgp1b sparc ), proteolytic enzyme ctsk ) transcription factors sox9a s ox9b ihha runx2 rankl ). Although transcriptional overexpression 40 1.6 160 BPA, increased detected only E2-exposed larvae, suggesting difference skeleton development remodeling BPA-treated larvae. Discussion Our results suggest phenotypic differences could be due implication other estrogenic pathways involving nuclear membrane-bound receptors (ERs GPERs), but also estrogen-related (ERRs). This study brings new insights into mechanisms by BPA effects on teleost fishes.