Development of sodium regulation and De Novo synthesis of NA + K-activated ATPase in larval brine shrimp, Artemia salina
The development of brine shrimp embryos, A. salina, incubated in media of increasing salinity is delayed as evidenced by decreased emergence and lengthening of the time for excystment. Prehydration of cysts at low temperature (3/sup 0/C) for four to ten hours in distilled water eliminates asynchrony of the population in regard to emergency and hatching times. Internal concentration glycerol, which controls the rate of hydration of the cyst stage, is markedly affected by external salinity. Water balance in the cyst stage is maintained via the trehalose-glycerol mechanism which generates a simple passive diffusional gradient across the chitinous shell allowing water to pass. Non-gaseous solutes, such as sodium and glycerol, do not pass through the chitin-membrane barrier. Rupturing the shell by emergence initiates the onset of the prenaupliar stage; it is accompanied by the appearance of large amounts of free glycerol in the external media, decreasing levels of internal glycerol, increased concentrations of internal sodium and the first detectable levels of the cationic transport enzyme, Na + K-ATPase. Continual loss of free glycerol through the cellular and hatching membranes causes the excysting embryo to convert from a trehalose-glycerol mechanism to a sodium-mediated transport system in order to maintain larval water balance. Ontogeny of the sodium regulating mechanism requires formation of Na + K-ATPase. The production of new Na + K-ATPase, as evidenced by incorporation of /sup 14/C-amino acids into polypeptide subunits and density-gradient centrifugation of radioactive membrane vesicles rich in Na + K-ATPase, may play an important role and, if so, it appears to be initiated between E-1 and E-2 stages.
- Research Organization:
- Oregon State Univ., Corvallis
- OSTI ID:
- 6857334
- Journal Information:
- J. Exp. Zool.; (United States), Vol. 202:3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Embryonic diapause in two species of brine shrimp: Artemia monica and Artemia franciscana
Large scale partial purification and molecular and kinetic properties of the (Na + K)-activated adenosine triphosphatase from Artemia salina nauplii
Related Subjects
ATP-ASE
BIOSYNTHESIS
CARBON 14 COMPOUNDS
TRACER TECHNIQUES
BIOCHEMISTRY
BIOLOGICAL PATHWAYS
LARVAE
METAMORPHOSIS
PHYSIOLOGY
POTASSIUM
SHRIMP
SODIUM
ACID ANHYDRASES
ALKALI METALS
ANIMALS
AQUATIC ORGANISMS
ARTHROPODS
CHEMISTRY
CRUSTACEANS
DECAPODS
ELEMENTS
ENZYMES
HYDROLASES
INVERTEBRATES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
METALS
PHOSPHOHYDROLASES
SYNTHESIS
550201* - Biochemistry- Tracer Techniques
551001 - Physiological Systems- Tracer Techniques