. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 318 W. B. AND D. T. MANAHAN pur/>iiratusandDendraslere.\centricus)(Manahanet al., 1983; Davis and Stephens, 1984). Manahan (1983) examined the biochemical fate of 14C from transported amino acids in two bivalve veligers, Crassostrea gigas and Mytilus editlis. The patterns of carbon assimilation were similar following a 100-min ex- posure to fiM 14C-amino acid for C gigas (glycine) and M. edulis (alanine). The majority of the radioactivity (75%) in the larva was localized in the cold trichloroace- tic acid (TC
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 318 W. B. AND D. T. MANAHAN pur/>iiratusandDendraslere.\centricus)(Manahanet al., 1983; Davis and Stephens, 1984). Manahan (1983) examined the biochemical fate of 14C from transported amino acids in two bivalve veligers, Crassostrea gigas and Mytilus editlis. The patterns of carbon assimilation were similar following a 100-min ex- posure to fiM 14C-amino acid for C gigas (glycine) and M. edulis (alanine). The majority of the radioactivity (75%) in the larva was localized in the cold trichloroace- tic acid (TCA)-soluble fraction, 20-25% was associated with the TCA-insoluble pellet, and virtually no label was found in the lipid fraction (<2%). The production of I4CO2 by C gigas larvae, measured in parallel, repre- sented 33% of the total glycine transport (the sum of iso- tope in the larva and respired radioactivity). Based on these published accounts, most plankto- trophic larvae should have the ability to remove amino acids from seawater and incorporate the acquired sub- strates in metabolism. However, quantitative interpreta- tion of the rate of substrate transport and metabolism has been hampered by the fact that the majority of these experiments were conducted in the presence of bacteria. Heterotrophic bacteria can take up amino acids and other forms of DOM from seawater and use these com- pounds for growth and metabolism (Williams. 1975). Hence, the metabolic activity of bacteria may confound the results of studies on the ability of larvae to transport and metabolize amino acids. For instance, in adult sea urchins (Strongylocentrotus droebachiensis) the activity of intestinal (surface-adherent) bacteria appears to con- vert radiolabeled glucose to "essential" amino acids (Fong and Mann, 1980). Attempts have been made to eliminate bacteria from larval cultures by the addition of antibiotics (Millar and Scott. 1967). but the effectiveness of antibiotic treatments on
Size: 914px × 2735px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
