Depression of protein synthesis during diapause in embryos of the annual killifish Austrofundulus limnaeus.
Physiol Biochem Zool
; 73(6): 799-808, 2000.
Article
en En
| MEDLINE
| ID: mdl-11121353
ABSTRACT
Rates of protein synthesis are substantially depressed in diapause II embryos of Austrofundulus limnaeus. Inhibition of oxygen consumption and heat dissipation with cycloheximide indicates that 36% of the adenosine triphosphate (ATP) turnover in prediapausing embryos (8 d postfertilization [dpf]) is caused by protein synthesis; the contribution of protein synthesis to ATP turnover in diapause II embryos is negligible. In agreement with the metabolic data, incorporation of amino acids (radiolabeled via (14)CO(2)) into perchloric acid-precipitable protein decreases by over 93% in diapause II embryos compared with embryos at 8 dpf. This result represents a 36% reduction in energy demand because of depression of protein synthesis during diapause. Adjusting for changes in the specific radioactivity of the free amino acid pool at the whole-embryo level yields rates of protein synthesis that are artifactually high and not supportable by the observed rates of oxygen consumption and heat dissipation during diapause. This result indicates a regionalized distribution of labeled amino acids likely dictated by a pattern of anterior to posterior cell cycle arrest. AMP/ATP ratios are strongly correlated with the decrease in rates of protein synthesis, which suggests a role for adenosine monophosphate (AMP) in the control of anabolic processes. The major depression of protein synthesis during diapause II affords a considerable reduction in energy demand and extends the duration of dormancy attainable in these embryos.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Biosíntesis de Proteínas
/
Peces Killi
Límite:
Animals
Idioma:
En
Revista:
Physiol Biochem Zool
Asunto de la revista:
BIOLOGIA
/
FISIOLOGIA
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos