The fluted giant clam (Tridacna squamosa) increases the protein abundance of the host's copper-zinc superoxide dismutase in the colorful outer mantle, but not the whitish inner mantle, during light exposure
| Autor: | Wai P. Wong, Mel V. Boo, Yuen K. Ip, Kum C. Hiong, Shit F. Chew, Clarissa Z. Y. Koh |
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| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Light Physiology Color 01 natural sciences Biochemistry Superoxide dismutase 03 medical and health sciences Animals Photosynthesis Mantle (mollusc) Molecular Biology 030304 developmental biology chemistry.chemical_classification 0303 health sciences Reactive oxygen species biology Superoxide Dismutase Chemistry 010604 marine biology & hydrobiology Proteins Ctenidium biology.organism_classification Tridacna Bivalvia Fluted giant clam Cell biology Zooxanthellae Dinoflagellida biology.protein Hepatopancreas |
| Zdroj: | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 250:110791 |
| ISSN: | 1095-6433 |
| DOI: | 10.1016/j.cbpa.2020.110791 |
| Popis: | The colorful outer mantle of giant clams contains abundance of symbiotic dinoflagellates (zooxanthellae) and iridocytes, and has direct exposure to light. In light, photosynthesizing dinoflagellates produce O2, and the host cells in the outer mantle would be confronted with hyperoxia-related oxidative stress. In comparison, the whitish inner mantle contains few symbiotic dinoflagellates and no iridocytes. It is involved in shell formation, and is shaded from light. CuZnSOD is a cytosolic enzyme that scavenges intracellular O2 -. We had obtained from the outer mantle of the fluted giant clam, Tridacna squamosa, the complete cDNA coding sequence of a host-derived copper zinc superoxide dismutase (CuZnSOD), which comprised 462 bp and encoded for 154 amino acids with a calculated MW of 15.6 kDa. CuZnSOD was expressed strongly in the outer mantle, ctenidium, hepatopancreas and kidney. The transcript level of CuZnSOD remained unchanged in the outer mantle during light exposure, but the protein abundance of CuZnSOD increased ~3-fold after exposure to light for 6 or 12 h. By contrast, 12 h of light exposure had no significant effects on the gene and protein expression levels of CuZnSOD/CuZnSOD in the inner mantle. Hence, the increased expression of CuZnSOD in the outer mantle of T. squamosa was probably a host's response to ameliorate oxidative stress related to photosynthesis in the symbionts, and not simply due to increased metabolic rate in the host cells. Evidently, the host clam must possess light- or O2-responsive anti-oxidative defenses in order to align with the light-dependent photosynthetic activity of its symbionts. |
| Databáze: | OpenAIRE |
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