title: The role of ontogeny in physiological tolerance: decreasing hydrostatic pressure tolerance with development in the northern stone crab Lithodes maja.
abstract: Extant deep-sea invertebrate fauna represent both ancient and recent invasions from shallow-water habitats. Hydrostatic pressure may present a significant physiological challenge to organisms seeking to colonize deeper waters or migrate ontogenetically. Pressure may be a key factor contributing to bottlenecks in the radiation of taxa and potentially drive speciation. Here, we assess shifts in the tolerance of hydrostatic pressure through early ontogeny of the northern stone crab Lithodes maja, which occupies a depth range of 4-790 m in the North Atlantic. The zoea I, megalopa and crab I stages were exposed to hydrostatic pressures up to 30.0 MPa (equivalent of 3000 m depth), and the relative fold change of genes putatively coding for the N-methyl-D-aspartate receptor-regulated protein 1 (narg gene), two heat-shock protein 70 kDa (HSP70) isoforms and mitochondrial Citrate Synthase (CS gene) were measured. This study finds a significant increase in the relative expression of the CS and hsp70a genes with increased hydrostatic pressure in the zoea I stage, and an increase in the relative expression of all genes with increased hydrostatic pressure in the megalopa and crab I stages. Transcriptional responses are corroborated by patterns in respiratory rates in response to hydrostatic pressure in all stages. These results suggest a decrease in the acute high-pressure tolerance limit as ontogeny advances, as reflected by a shift in the hydrostatic pressure at which significant differences are observed.
authors.affiliation: Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, European Way, Southampton SO14 3ZH, UK.
authors.forename: Catriona
authors.initials: C
authors.lastname: Munro
authors.affiliation: Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, European Way, Southampton SO14 3ZH, UK.
authors.forename: James P
authors.initials: JP
authors.lastname: Morris
authors.affiliation: Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, European Way, Southampton SO14 3ZH, UK.
authors.forename: Alastair
authors.initials: A
authors.lastname: Brown
authors.affiliation: Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, European Way, Southampton SO14 3ZH, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Hauton
authors.affiliation: Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, European Way, Southampton SO14 3ZH, UK svth@noc.soton.ac.uk.
authors.forename: Sven
authors.initials: S
authors.lastname: Thatje
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003386:Brachyura / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D002950:Citrate (si)-Synthase / Q000235:genetics / Q000378:metabolism; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006874:Hydrostatic Pressure; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism; D012119:Respiration; D016415:Sequence Alignment; D014158:Transcription, Genetic
chemical_list: D060829:Arthropod Proteins; D018840:HSP70 Heat-Shock Proteins; D016194:Receptors, N-Methyl-D-Aspartate; D002950:Citrate (si)-Synthase
keywords: Lithodidae; deep sea; evolution; hydrostatic pressure; physiological bottleneck; species radiation