title: The expression of hypoxia-inducible factor-1α gene is not affected by low-oxygen conditions in yellow perch (Perca flavescens) juveniles.
abstract: Hypoxia can affect various fish populations, including yellow perch Perca flavescens, which is an economically and ecologically important species in Lake Erie, a freshwater system that often experiences hypoxia in the hypolimnetic part of the lake. Fish, similarly to mammals, possess molecular oxygen sensor-hypoxia-inducible factor-1 (HIF-1), a transcription factor that can affect expression of many downstream genes related to animal growth and locomotion, protein synthesis, as well as ATP and amino acid metabolism. HIF-1 is a heterodimer, which consists of two subunits: oxygen-sensitive and oxygen-insensitive subunits, α and β, respectively. In this study, we report first on the molecular cloning and sequencing of P. flavescens HIF-1α. The full-length complementary DNA (cDNA) was isolated and submitted to the GenBank with accession number KT783483. It consists of 3529 base pairs (bp) carrying a single open-reading frame that encompasses 2250 bp of the coding region, 247 bp of the 5' untranslated region (UTR), and 1032 bp of the 3' UTR. The "de novo" prediction of the 3D structure of HIF-1α protein, which consists of 749 amino acids, is presented, too. We then utilized One-Step Taqman® real-time RT-PCR technology to monitor changes in HIF-1α messenger RNA (mRNA) copies in response to chronic hypoxic stress. An experiment was conducted using 14-day post-swim-up stage yellow perch larvae with uninflated swim bladders. This experiment included three treatment groups: hypoxia, mid-hypoxia, and normoxia, in four replicates (four tanks per treatment) with the following dissolved oxygen levels: 3, 4, and >7 mg O2/L, respectively. At the end (2 weeks) and in the middle (1 week) of the experiment, fish from each tank were sampled for body measurements and molecular biology analysis. The results showed no differences in survival (∼90%) between treatment groups. Oxygen concentration was lowered to 3.02 ± 0.15 (mean ± SE) mg O2/L with no adverse effect on fish survival. The highest growth rate was observed in the normoxic group. A similar trend was observed with fish body length. The growth rate of fish declined with decreasing water-dissolved oxygen. The number of HIF-1α mRNA copies was not significantly different between hypoxic, mid-hypoxic, and normoxic conditions, and this was true for fish obtained in the middle and at the end of the experiment. Graphical abstract.
authors.affiliation: School of Environment and Natural Resources, Ohio State University, Columbus, OH, 43210, USA.|Department of Biotechnology and Life Sciences, University of Insubria, Via Dunant, 3, 21100, Varese, Italy.
authors.forename: Karolina
authors.initials: K
authors.lastname: Kwasek
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, Via Dunant, 3, 21100, Varese, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Rimoldi
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, Via Dunant, 3, 21100, Varese, Italy.
authors.forename: Anna Giulia
authors.initials: AG
authors.lastname: Cattaneo
authors.affiliation: School of Environment and Natural Resources, Ohio State University, Columbus, OH, 43210, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Parker
authors.affiliation: School of Environment and Natural Resources, Ohio State University, Columbus, OH, 43210, USA.
authors.forename: Konrad
authors.initials: K
authors.lastname: Dabrowski
authors.affiliation: Department of Biotechnology and Life Sciences, University of Insubria, Via Dunant, 3, 21100, Varese, Italy. genciana.terova@uninsubria.it.|Inter-University Centre for Research in Protein Biotechnologies "The Protein Factory", Polytechnic University of Milan and University of Insubria, Varese, Italy. genciana.terova@uninsubria.it.
authors.forename: Genciana
authors.identifier: http://orcid.org/0000-0002-7532-7951
authors.initials: G
authors.lastname: Terova
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D010100:Oxygen / Q000494:pharmacology*; D010471:Perches / Q000502:physiology*; D012313:RNA / Q000235:genetics / Q000378:metabolism; D014867:Water / Q000737:chemistry
chemical_list: D018076:DNA, Complementary; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D014867:Water; D012313:RNA; D010100:Oxygen
keywords: 3D protein structure; HIF-1α; Hypoxia; Lake Erie; Mid-hypoxia; Normoxia; Taqman real-time PCR; Yellow perch