Low salinity-induced alterations in epithelial ultrastructure, Na+/K+-ATPase immunolocalization and enzyme kinetic characteristics in the gills of the thinstripe hermit crab, Clibanarius vittatus (Anomura, Diogenidae)

Autor(es)

Antunes, Claudia Doi ^{[1, 2]} ; Lucena, Malson Neilson ^[3] ; Garcon, Daniela Pereira ^[4] ; Leone, Francisco Assis ^[3] ; McNamara, John Campbell ^{[1, 2]}

Afiliação do(s) autor(es)

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

^[2] Univ Sao Paulo, Ctr Biol Marinha, Sao Sebastiao, SP - Brazil

^[3] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, Ribeirao Preto, SP - Brazil

^[4] Univ Fed Triangulo Mineiro, Campus Univ Iturama, Iturama, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY; v. 327, n. 6, p. 380-397, JUL 2017.
• Citações Web of Science: 2

Resumo

Fresh caught Clibanarius vittatus {[}SW, 31 parts per thousand salinity (S)] were acclimated to a dilute medium (15 parts per thousand S) for 10 days, employing silver staining to locate gill ion transporting tissue, immunofluorescence to localize the Na+/K+-ATPase alpha-subunit in the lamellae, and electron microscopy to portray ultrastructural changes in the gill epithelia. Na+/K+-ATPase activity was characterized kinetically in a gill microsomal fraction, including synergistic stimulation by NH4+ plus K+. Silver staining revealed that all 26 phyllobranchiate arthro-and pleurobranchiae participate in ion transport. Na+/K+-ATPase alpha-subunit staining was weak in SW crabs and distributed exclusively and irregularly within the intralamellar septal cells, particularly at the septal-pillar cell body junctions, and septal cell cytoplasm facing the hemolymph space. In 15 parts per thousand S crabs, alpha-subunit localization was intense, occupying the entire thickened septum. Pillar cells and flanges did not stain. Mitochondria and membrane foldings increased in the pillar cell flanges and intralamellar septal cells, greatly amplifying surface area. Only a single ATP binding site (V-M = 130.8 +/- 10.5 nmol min(-1) mg protein(-1); K-0.5 = 55.3 +/- 1.7 mu mol l(-1)) obeying Michaelis-Menten kinetics was disclosed. Na+/K+-ATPase activity was modulated by Mg2+, Na+, and NH4+, exhibiting site-site interactions; K+ modulation showed Michaelis-Menten kinetics. K+ plus NH4+ synergistically stimulated activity approximate to 1.7-fold. Ouabain inhibited total ATPase activity by approximate to 70% (K-I = 220-300 mu mol l(-1)), revealing phosphohydrolytic activities other than the Na+/K+-ATPase. Despite ample phylogenetic separation, the phyllobranchiate lamellae of the Anomura and Caridea share many ultrastructural features, that is, an intralamellar septum and opposed abutting pillar cells, similar Na+/K+-ATPase distribution, and comparable kinetic characteristics. These findings suggest either convergent evolution at the structural and biochemical levels, or preservation of traits present in a remote common ancestor. (AU)

• Processo FAPESP: 10/50188-8 - Crustáceos decápodes: multidisciplinaridade na caracterização da biodiversidade marinha do estado de São Paulo (taxonomia, espermiotaxonomia, biologia molecular e dinâmica populacional) (Biodiversidade Marinha)
• Beneficiário: Fernando Luis Medina Mantelatto
• Linha de fomento: Auxílio à Pesquisa - Programa BIOTA - Temático
• Processo FAPESP: 13/24252-9 - O papel da (Na+,K+)-ATPase na capacidade osmorregulatória do caranguejo Ucides cordatus: uma abordagem bioquímica e molecular
• Beneficiário: Malson Neilson de Lucena
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/22605-1 - Caracterização cinética e molecular da (Na+,K+)-ATPase do tecido branquial do caranguejo Cardisoma guanhumi (Latreille)
• Beneficiário: Francisco de Assis Leone
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/17534-0 - Papel da (Na,K)-ATPase na osmorregulação e excreção de amônio em crustáceos eurialinos: identificação e efeitos do FXYD2 na regulação da (Na,K)-ATPase branquial do siri Callinectes danae
• Beneficiário: Francisco de Assis Leone
• Linha de fomento: Auxílio à Pesquisa - Regular