title: Stickleback embryos use ATP-binding cassette transporters as a buffer against exposure to maternally derived cortisol.
abstract: Offspring from females that experience stressful conditions during reproduction often exhibit altered phenotypes and many of these effects are thought to arise owing to increased exposure to maternal glucocorticoids. While embryos of placental vertebrates are known to regulate exposure to maternal glucocorticoids via placental steroid metabolism, much less is known about how and whether egg-laying vertebrates can control their steroid environment during embryonic development. We tested the hypothesis that threespine stickleback (Gasterosteus aculeatus) embryos can regulate exposure to maternal steroids via active efflux of maternal steroids from the egg. Embryos rapidly (within 72 h) cleared intact steroids, but blocking ATP-binding cassette (ABC) transporters inhibited cortisol clearance. Remarkably, this efflux of cortisol was sufficient to prevent a transcriptional response of embryos to exogenous cortisol. Taken together, these findings suggest that, much like their placental counterparts, developing fish embryos can actively regulate their exposure to maternal cortisol. These findings highlight the fact that even in egg-laying vertebrates, the realized exposure to maternal steroids is mediated by both maternal and embryonic processes and this has important implications for understanding how maternal stress influences offspring development.
authors.affiliation: School of Integrative Biology, University of Illinois, Urbana, IL 61801, USA School of Biological Sciences, Illinois State University, Campus Box 4120, Normal, IL 61790, USA rpaitz@ilstu.edu.
authors.forename: Ryan T
authors.identifier: http://orcid.org/0000-0003-4609-4359
authors.initials: RT
authors.lastname: Paitz
authors.affiliation: Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA Illinois Informatics Institute, University of Illinois, Urbana, IL 61801, USA.
authors.forename: Syed Abbas
authors.initials: SA
authors.lastname: Bukhari
authors.affiliation: School of Integrative Biology, University of Illinois, Urbana, IL 61801, USA Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA.
authors.forename: Alison M
authors.initials: AM
authors.lastname: Bell
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D002140:California; D004625:Embryo, Nonmammalian / Q000378:metabolism; D047108:Embryonic Development / Q000187:drug effects; D005260:Female; D029941:Fish Proteins / Q000378:metabolism*; D006854:Hydrocortisone / Q000378:metabolism* / Q000494:pharmacology; D010063:Ovum / Q000187:drug effects / Q000378:metabolism; D023701:Smegmamorpha / Q000254:growth & development / Q000378:metabolism*
chemical_list: D018528:ATP-Binding Cassette Transporters; D029941:Fish Proteins; D006854:Hydrocortisone
keywords: ABC transporter; embryo; fish; glucocorticoid; maternal effect; stress