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

Author(s)

Faleiros, Rogerio O. ^{[1, 2]} ; Garcon, Daniela P. ^{[1, 3]} ; Lucena, Malson N. ^{[1, 4]} ; McNamara, John C. ^{[5, 6]} ; Leone, Francisco A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, Ave Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Fed Jatai, Unidade Acad Especial Ciencias Biol, BR-75801615 Jatai, Go - Brazil

^[3] Univ Fed Triangulo Mineiro, BR-38280000 Iturama, MG - Brazil

^[4] Univ Fed Mato Grosso do Sul, Inst Biociencias, BR-79070900 Campo Grande, MS - Brazil

^[5] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Biol, BR-14040901 Ribeirao Preto, SP - Brazil

^[6] Univ Sao Paulo, Ctr Biol Marinha, BR-11000600 Sao Sebastiao, SP - Brazil

• Document type: Journal article
• Source: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY; v. 225, p. 16-25, NOV 2018.
• Web of Science Citations: 4

Abstract

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 alpha-subunit mRNA expression of the gill (Na+, K+)-ATPase. The crab strongly hyper-regulates its hemolymph at 5 and 15 parts per thousand S (Salinity, g L-1) but weakly hyper-regulates up to 27 parts per thousand S. After 6h exposure to 359 , 60S and 45 parts per thousand 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 alpha-subunit mRNA expression increases only after 10 days acclimation to 5 parts per thousand S. Our findings suggest that hemolymph hyper-regulation is effected by alterations in enzyme activity during shortterm 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. (AU)

• FAPESP's process: 13/24252-9 - The (Na+,K+)-ATPase in osmoregulatory capacity in crab Ucides cordatus: biochemical and molecular view
• Grantee: Malson Neilson de Lucena
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 10/17534-0 - Role of (Na,K)-ATPase in osmoregulation and excretion of ammonium ions in euryhaline crustaceans: identification and influence of FXYD2 on the regulation of gill (Na,K)-ATPase of the crab Callinectes danae
• Grantee: Francisco de Assis Leone
• Support type: Regular Research Grants
• FAPESP's process: 16/25336-0 - Comparative biochemical study of gill (Na+, K +)- ATPase of Macrobrachium amazonicum (Heller, 1862) inhabitant of coastal and continental regions
• Grantee: Francisco de Assis Leone
• Support type: Regular Research Grants