Short- and long-term salinity challenge, osmoregulatory ability, and (Na + , K + )-ATPase kinetics and α-subunit mRNA expression in the gills of the thinstripe hermit crab Clibanarius symmetricus (Anomura, Diogenidae).

Autor: Faleiros RO; Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, SP, Brazil; Unidade Acadêmica Especial de Ciências Biológicas, Universidade Federal de Jataí, Jataí 75801-615, GO, Brazil., Garçon DP; Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, SP, Brazil; Universidade Federal do Triângulo Mineiro, Iturama 38280-000, MG, Brazil., Lucena MN; Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, SP, Brazil; Instituto de Biociências, Universidade Federal do Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil., McNamara JC; Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, SP, Brazil; Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião 11000-600, SP, Brazil., Leone FA; Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, SP, Brazil. Electronic address: fdaleone@ffclrp.usp.br.
Jazyk: angličtina
Zdroj: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology [Comp Biochem Physiol A Mol Integr Physiol] 2018 Nov; Vol. 225, pp. 16-25. Date of Electronic Publication: 2018 Jun 19.
DOI: 10.1016/j.cbpa.2018.06.016
Abstrakt: The evolutionary history of the Crustacea reveals ample adaptive radiation and the subsequent occupation of many osmotic niches resulting from physiological plasticity in their osmoregulatory mechanisms. We evaluate osmoregulatory ability in the intertidal, thinstripe hermit crab Clibanarius symmetricus after short-term exposure (6 h) or long-term acclimation (10 days) to a wide salinity range, also analyzing kinetic behavior and α-subunit mRNA expression of the gill (Na + , K + )-ATPase. The crab strongly hyper-regulates its hemolymph at 5 and 15‰S (Salinity, g L -1 ) but weakly hyper-regulates up to ≈27‰S. After 6 h exposure to 35‰S and 45‰S, C. symmetricus slightly hypo-regulates its hemolymph, becoming isosmotic after 10 days acclimation to these salinities. (Na + , K + )-ATPase specific activity decreases with increasing salinity for both exposure periods, reflecting physiological adjustment to isosmoticity. At low salinities, the gill enzyme exhibits a single, low affinity ATP binding site. However, at elevated salinities, a second, high affinity, ATP binding site appears, independently of exposure time. (Na + , K + )-ATPase α-subunit mRNA expression increases only after 10 days acclimation to 5‰S. Our findings suggest that hemolymph hyper-regulation is effected by alterations in enzyme activity during short-term exposure, but is sustained by increased mRNA expression during long-term acclimation. The decrease in gill (Na + , K + )-ATPase activity seen as a consequence of increasing salinity appears to underlie biochemical adjustments to hemolymph isosmoticity as hypo-regulatory ability diminishes.
(Copyright © 2018 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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