A field and laboratory study of the responses of cytoprotection and osmoregulation to salinity stress in mosquitofish (Gambusia affinis).
Fish Physiol Biochem
; 44(2): 489-502, 2018 Apr.
Article
em En
| MEDLINE
| ID: mdl-29192359
ABSTRACT
The mosquitofish (Gambusia affinis) naturally inhabits freshwater (FW; 1-3) and seawater (SW; 28-33) ponds in constructed wetland. To explore the physiological status and molecular mechanisms for salinity adaptation of the mosquitofish, cytoprotective responses and osmoregulation were examined. In the field study, activation of protein quality control (PQC) mechanism through upregulation of the abundance of heat shock protein (HSP) 90 and 70 and ubiquitin-conjugated proteins was found in the mosquitofish gills from SW pond compared to the individuals of FW pond. The levels of aggregated proteins in mosquitofish gills had no significant difference between FW and SW ponds. Furthermore, the osmoregulatory responses revealed that the body fluid osmolality and muscle water contents of the mosquitofish from two ponds were maintained within a physiological range while branchial Na+/K+-ATPase (NKA) expression was higher in the individuals from SW than FW ponds. Subsequently, to further clarify whether the cellular stress responses and osmoregulation were mainly induced by hypertonicity, a laboratory salinity acclimation experiment was conducted. The results from the laboratory experiment were similar to the field study. Branchial PQC as well as NKA responses were induced by SW acclimation compared to FW-acclimated individuals. Taken together, induction of gill PQC and NKA responses implied that SW represents an osmotic stress for mosquitofish. Activation of PQC was suggested to provide an osmoprotection to prevent the accumulation of aggregated proteins. Moreover, an increase in branchial NKA responses for osmoregulatory adjustment was required for the physiological homeostasis of body fluid osmolality and muscle water content.
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MEDLINE
Assunto principal:
Ciprinodontiformes
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Regulação da Expressão Gênica
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ATPase Trocadora de Sódio-Potássio
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Citoproteção
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Salinidade
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Osmorregulação
Limite:
Animals
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article