High taurine levels in the Solemya velum symbiosis
Autor: | Judith M. Capuzzo, Noellette M. Conway |
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Rok vydání: | 1992 |
Předmět: |
Taurine
Physiology Solemya velum chemistry.chemical_element Biochemistry chemistry.chemical_compound Species Specificity Symbiosis Animals Amino Acids Molecular Biology Mollusca chemistry.chemical_classification Bacteria biology Proteins General Medicine biology.organism_classification Bivalvia Sulfur Amino acid chemistry |
Zdroj: | Comparative Biochemistry and Physiology Part B: Comparative Biochemistry. 102:175-185 |
ISSN: | 0305-0491 |
DOI: | 10.1016/0305-0491(92)90292-y |
Popis: | 1. 1. To compare biochemical differences between bivalves with and without endosymbiotic chemoautotrophic bacteria, specimens of Solemya velum, a bivalve species known to contain bacterial endosymbionts, and the symbiont-free soft-shelled clam Mya arenaria, were collected from the same subtidal reducing sediments during October and November 1988. 2. 2. Total and free amino acid compositions were determined for both species. Protein-bound amino acids were calculated as the difference between total and free amino acids. In addition, stable isotope ratios of the total and free amino acids of each species were measured to determine potential sources for these molecules. 3. 3. Both species had similar total hydrolyzable- and protein-bound amino acid compositions; approximately 50% of the protein-bound amino acids were essential amino acids. In S. velum, the small size of the digestive system suggests that these amino acids are probably synthesized by the endosymbiotic bacteria and translocated to the animal tissue. The δ13C and δ15N ratios of the amino acids are very similar to the isotope ratios previously found in both the endosymbionts and whole tissues of S. velum. The relative and absolute amounts of free amino acids are very different in the two species. In S. velum, the absolute concentrations of taurine, a sulfur-containing amino acid, were greater than the total free amino acid concentrations found in other bivalves. 4. 4. The δ34S ratios of the free amino acids of S. velum, which were predominantly composed of taurine, were extremely negative (−17.2ℵ) suggesting that taurine is synthesized using sulfur originally derived from external reduced sulfur sources, such as pore water sulfides. The possible roles for taurine in this animal-bacteria symbiosis are discussed. |
Databáze: | OpenAIRE |
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