When the chlorophyte alga Dunaliella tertiolecta Butcher is placed in darkness, a form of programmed cell death with many similarities to apoptosis is induced, including the induction of caspase-like proteases. Many uncertainties about the regulation and mediators that participate in the process remain. To examine the relationship between caspase-like activities and different apoptotic events (...

Dunaliella tertiolecta was disrupted mechanically and resolved by centrifugation into chloro­ plast* and cytosol-enriched fractions. Intact chloroplasts could not be isolated because peripheral extensions of the single large chloroplast reached almost to the flagellar pole o f the cell. The chloroplast envelope was closely appressed to the plasmalemma and, because o f this and its dimensions, w...

Two isoforms of dihydroxyacetone phosphate reductase were present in Dunaliella tertiolecta. The major form was located in the chloroplast and the minor form in the cytosol. The chloroplastic reductase eluted first from a DEAE cellulose column followed immediately by the cytosolic form. Both forms were unstable and cold labile. Addition of 5 millimolar dithiothreitol helped to stabilize the enz...

The eukaryotic green alga Dunaliella tertiolecta acclimates to decreased growth irradiance by increasing cellular levels of light-harvesting chlorophyll protein complex apoproteins associated with photosystem II (LHCIIs), whereas increased growth irradiance elicits the opposite response. Nuclear run-on transcription assays and measurements of cab mRNA stability established that light intensity-...

The efficiency with which absorbed light is converted to net growth is a key property for estimating global carbon production. We previously showed that, despite considerable evolutionary distance, Dunaliella tertiolecta (Chlorophyceae) and Thalassiosira weissflogii (Bacillariophyceae) share a common strategy of photosynthetic energy utilization and nearly identical light energy conversion effi...

Ingestion rates, faecal pellet and egg production were obtained in laboratory experiments with females of the copepod Calanus helgolandicus collected from the English Channel in November 1994. Five different algal monocultures were used as food: Prorocentrum micans (30 µm ESD), Thalassiosira weissflogii (13 µm ESD), Dunaliella tertiolecta (7 µm ESD), Emiliania huxleyi (5 µm ESD) and Coccolithus...

The mean specific biovolumes (biovolume cell) of the bacterioplankton within a 250-m-deep water column in Howe Sound, British Columbia, were determined for the period of 4 September 1984 to 23 October 1985. These bacteria had an annual cycle in mean specific biovolume; they were small (ca. 0.058 mum) in mid-winter, larger in spring (ca. 0.076 mum), larger again in summer (up to 0.102 mum), and ...

We examined the relative importance of parental nutritional condition and larval food ration on the rates of development, growth and metamorphosis of larvae of Strongylocentrotus droebacḧ iensis (Muller) in a laboratory experiment. Parents were reared for 22 months on either a high 21 ration of kelp (Laminaria spp., 6 days week ) supplemented with mussel flesh (Mytilus spp., 1 21 21 day week ) ...