Impact of bisphenol A (BPA) on early embryo development in the marine mussel Mytilus galloprovincialis: Effects on gene transcription

Abstract

Bisphenol A (BPA), a monomer used in plastic manufacturing, is weakly estrogenic and a potential endocrine disruptor in mammals. Although it degrades quickly, it is pseudo-persistent in the environment because of continual inputs, with reported concentrations in aquatic environments between 0.0005 and 12 μg/L. BPA represents a potential concern for aquatic ecosystems, as shown by its reproductive and developmental effects in aquatic vertebrates. In invertebrates, endocrine-related effects of BPA were observed in different species and experimental conditions, with often conflicting results, indicating that the sensitivity to this compound can vary considerably among related taxa. In the marine mussel Mytilus galloprovincialis BPA was recently shown to affect early development at environmental concentrations. In this work, the possible effects of BPA on mussel embryos were investigated at the molecular level by evaluating transcription of 13 genes, selected on the basis of their biological functions in adult mussels. Gene expression was first evaluated in trocophorae and D-veligers (24 and 48 h post fertilization) grown in physiological conditions, in comparison with unfertilized eggs. Basal expressions showed a general up-regulation during development, with distinct transcript levels in trocophorae and D-veligers. Exposure of fertilized eggs to BPA (10 μg/L) induced a general upregulation at 24 h pf, followed by down regulation at 48 h pf. Mytilus Estrogen Receptors, serotonin receptor and genes involved in biomineralization (Carbonic Anydrase and Extrapallial Protein) were the most affected by BPA exposure. At 48 h pf, changes in gene expression were associated with irregularities in shell formation, as shown by scanning electron microscopy (SEM), indicating that the formation of the first shelled embryo, a key step in mussel development, represents a sensitive target for BPA. Similar results were obtained with the natural estrogen 17β-estradiol. The results demonstrate that BPA and E can affect Mytilus early development through dysregulation of gene transcription.

Autophagic processes in Mytilus galloprovincialis hemocytes: Effects of Vibrio tapetis

“…The results show that in mussel hemocytes V. tapetis induced a time dependent decrease in the immunoreactive band corresponding to p-mTor. Transcripts for mTor have been identified in the tissues Mytilus edulis [30]; moreover, we have recently shown that the level of mRNA for mTor are significantly modulated during early embryo development in M. galloprovincialis [31]. However, in the present work, Western blot with antibodies to total, unphosphorylated mTor showed a high variability of the signal in control hemocytes (not shown); therefore, the level of p-mTor was evaluated by densitometric analysis of the mTor/actin ratio.…”

Shift in Immune Parameters After Repeated Exposure to Nanoplastics in the Marine Bivalve Mytilus

“…EPp, the most abundant serum protein in M. galloprovincialis, is an acidic, histidine-rich, cation binding glycoprotein; it has a complex and anomalous N-glycan structure and contains a conserved C1q complement domain. Due to its peculiar composition, EPp is involved in multiple functions, from shell formation to immune response (42)(43)(44). This protein has been shown to play a key role in specific recognition of both selected bacterial strains and NP types.…”

Transgenerational effects on development following microplastic exposure in Drosophila melanogaster

“…Our study showed no effect of the plastic treatments in the capacity to fight viral infections in D. melanogaster . Previous studies had reported effects in the immune system of several models by increase of immune cell numbers, physiological changes or protein or gene overexpression ( Canesi et al, 2015 ; Balbi et al, 2016 ; Greven et al, 2016 ; Sadler, Brunner & Plaistow, 2019 ; Hirt & Body-Malapel, 2020 ). Other studies found injection of latex beads (composed of polystyrene) used to block phagocytosis ( Elrod-Erickson, Mishra & Schneider, 2000 ) can increase susceptibility to some pathogens ( Costa et al, 2009 ; Lamiable et al, 2016 ).…”