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Previous literature on prenatal phenol exposure and thyroid hormone (TH) alteration is conflicting, and the possible mechanisms of action involved remain unclear. We aimed to examine the association between prenatal phenol exposure and levels of maternal and neonatal THs, as well as the possible role of iodothyronine deiodinase (DIO) gene polymorphisms in this relation.We studied 387 Spanish mother-neonate pairs with measurements of maternal phenols, total triiodothyronine (TT3) and free thyroxine (FT4), maternal and neonatal thyroid-stimulating hormone (TSH), and maternal ge-notypes for single nucleotide polymorphisms in the DIO1(rs2235544) and DIO2(rs12885300) genes. We implemented multivariate linear and weighted quantile sum (WQS) regressions to examine the association be-tween phenols and THs (including sex-stratified models for neonatal TSH) and investigated effect modification of genotypes in the maternal phenol-TH associations.In single exposure models, we found negative associations between maternal triclosan (TCS) and neonatal TSH (% change [95%CI]:-2.95 [-5.70,-0.11], per twofold phenol increase) - stronger for girls - and less clearly for maternal ethylparaben (EPB) and TSH (-2.27 [-4.55, 0.07]). In phenol mixture models, we found no association with THs. In the genetic interaction models, we found some evidence of effect modification of DIO gene poly-morphisms with stronger negative associations between methylparaben (MPB), propylparaben (PPB), butyl-paraben (BPB) and TT3 as well as bisphenol A (BPA) and FT4 for DIO1(rs2235544)-CC. Stronger inverse associations for genotypes DIO2(rs12885300)-CC and DIO2(rs12885300)-CT and positive ones for DIO2 (rs12885300)-TT were also reported for BPA and FT4.In conclusion, we found some evidence of an association between phenols and TSH during pregnancy and at birth in single exposure models, the latter being stronger for girls. Since no association was observed between maternal levels of phenols and TT3 or FT4, the possible role of the genetic background in these associations warrants further investigation.

The cultivation of oyster presents some problems related with the identification and differentiation of species as Ostrea edulis (European flat oyster) with respect to Ostrea stentina (Provence oyster) or Crassostrea angulata (portuguese oyster). Crossostrea gigas (Pacific oyster). We have characterized a satellite DNA family and used it as a molecular marker for genetic differentiation between commercial and non-commercial oyster species present in Europe. This marker clearly supports a high degree of differentiation between O. edulis and O. stentina and conversely upholds the contention that C. gigas and C. angulata are the same species.