The ability of cysts of the brine shrimp, Artemia salina, to incorporate WO, into organic compounds soluble in cold-trichloroacetic acid was examined over a broad range of cellular water concentrations. Carbon dioxide was not incorporated by cysts containing less than about 0.3 g HzO/g dried cysts,
Interrelationships between water and cellular metabolism in Artemia cysts. VI. RNA and protein synthesis
β Scribed by James S. Clegg
- Publisher
- John Wiley and Sons
- Year
- 1977
- Tongue
- English
- Weight
- 828 KB
- Volume
- 91
- Category
- Article
- ISSN
- 0021-9541
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β¦ Synopsis
Abstract
Using ^14^CO~2~ as a labelled precursor the relationship between the initiation of protein and RNA synthesis, and water concentration, has been examined in cysts (encysted embryos) of the brine shrimp, Artemia salina. Although incorporation of radioactivity into amino acids and nucleotides occurred in cysts at hydrations as low as 0.3 g H~2~O/g dried cysts, incorporation into proteins and RNA was not measurable until the cysts had achieved a hydration in the range of 0.6β0.6 g/g. In no case was radioactivity detected in DNA of unemerged cysts. Fully hydrated cysts (about 1.3 g/g) that were actively synthesizing proteins and RNA, stopped doing so when dehydrated to levels below the same hydration range: thus, the hydration dependence does not involve appreciable hysteresis. The hydration range required to initiate synthesis of these macromolecules is essentially the same as that previously shown to initiate embryonic development.
π SIMILAR VOLUMES
## Abstract The concentration of total ninhydrinβpositive material (NPM) soluble in 5% trichloroacetic acid was measured in cysts of the brine shrimp, __Artemia salina__, as a function of hydration level. No net change in NPM was observed until the cysts had achieved a water content of about 0.65 g
## Abstract The concentration of ATP in cysts of the brine shrimp, __Artemia salina__, has been studied as a function of cyst hydration. Cysts dried over CaSO~4~ contain 0.02 gH~2~O/g cysts and 0.54 Β± 0.05 (S.D.) mΜmoles of ATP/g dried cysts. Addition of water up to 0.05 g/g cysts produced no net c