Rees Bernard B.

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Bernard B.

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  • Preprint
    Sequence and functional characterization of hypoxia inducible factors, HIF1α, HIF2αa, and HIF3α, from the estuarine fish, Fundulus heteroclitus
    ( 2016-11) Townley, Ian K. ; Karchner, Sibel I. ; Skripnikova, Elena ; Wiese, Thomas E. ; Hahn, Mark E. ; Rees, Bernard B.
    The hypoxia inducible factor (HIF) family of transcription factors plays central roles in the development, physiology, pathology, and environmental adaptation of animals. Because many aquatic habitats are characterized by episodes of low dissolved oxygen, fish represent ideal models to study the roles of HIF in the response to aquatic hypoxia. The estuarine fish Fundulus heteroclitus occurs in habitats prone to hypoxia, it responds to low oxygen via behavioral, physiological, and molecular changes, and one member of the HIF family, HIF2α, has been previously described. Herein, cDNA sequencing, phylogenetic analyses, and genomic approaches were used to determine other members of the HIFα family from F. heteroclitus and their relationships to HIFα subunits from other vertebrates. In vitro and cellular approaches demonstrated that full-length forms of HIF1α, 2α, and 3α independently formed complexes with the β subunit (ARNT) to bind to hypoxia response elements and activate reporter gene expression. Quantitative PCR showed that HIFα mRNA abundance varied among organs of normoxic fish in an isoform-specific fashion. Analysis of the F. heteroclitus genome revealed a locus encoding a second HIF2α, HIF2αb, a predicted protein lacking oxygen sensing and transactivation domains. Finally, sequence analyses demonstrated polymorphism in the coding sequence of each F. heteroclitus HIFα subunit, suggesting that genetic variation in these transcription factors may play a role in the variation in hypoxia responses among individuals or populations.
  • Preprint
    Fundulus as the premier teleost model in environmental biology : opportunities for new insights using genomics
    ( 2007-09-01) Burnett, Karen G. ; Bain, Lisa J. ; Baldwin, William S. ; Callard, Gloria V. ; Cohen, Sarah ; Di Giulio, Richard T. ; Evans, David H. ; Gomez-Chiarri, Marta ; Hahn, Mark E. ; Hoover, Cindi A. ; Karchner, Sibel I. ; Katoh, Fumi ; MacLatchy, Deborah L. ; Marshall, William S. ; Meyer, Joel N. ; Nacci, Diane E. ; Oleksiak, Marjorie F. ; Rees, Bernard B. ; Singer, Thomas D. ; Stegeman, John J. ; Towle, David W. ; Van Veld, Peter A. ; Vogelbein, Wolfgang K. ; Whitehead, Andrew ; Winn, Richard N. ; Crawford, Douglas L.
    A strong foundation of basic and applied research documents that the estuarine fish Fundulus heteroclitus and related species are unique laboratory and field models for understanding how individuals and populations interact with their environment. In this paper we summarize an extensive body of work examining the adaptive responses of Fundulus species to environmental conditions, and describe how this research has contributed importantly to our understanding of physiology, gene regulation, toxicology, and ecological and evolutionary genetics of teleosts and other vertebrates. These explorations have reached a critical juncture at which advancement is hindered by the lack of genomic resources for these species. We suggest that a more complete genomics toolbox for F. heteroclitus and related species will permit researchers to exploit the power of this model organism to rapidly advance our understanding of fundamental biological and pathological mechanisms among vertebrates, as well as ecological strategies and evolutionary processes common to all living organisms.