Bivalves are NO Different: Nitric Oxide as Negative Regulator of Metamorphosis in the Pacific Oyster, Crassostrea Gigas
| Autor: | Sean J. Monaghan, Jacqueline H Ireland, Xiaoxu Li, Alyssa Joyce, Nancy Nevejan, Stefano Carboni, Susanne Vogeler |
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| Rok vydání: | 2020 |
| Předmět: |
Oyster
Bivalves animal structures media_common.quotation_subject Receptors N-Methyl-D-Aspartate Nitric oxide 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Nitric oxide synthase NOS biology.animal Animals Pacific oyster Nitric Oxide Donors Metamorphosis Crassostrea Enzyme Inhibitors Cyclic GMP 030304 developmental biology media_common 0303 health sciences Larva biology fungi Metamorphosis Biological biology.organism_classification Cell biology Nitric oxide synthase cGMP chemistry Crassostrea gigas biology.protein Nitric Oxide Synthase Soluble guanylyl cyclase Developmental biology 030217 neurology & neurosurgery Developmental Biology Signal Transduction Research Article |
| Zdroj: | BMC Developmental Biology |
| DOI: | 10.21203/rs.3.rs-48020/v1 |
| Popis: | BackgroundNitric oxide (NO) is presumed to be a regulator of metamorphosis in many invertebrate species, and although NO pathways have been comparatively well-investigated in gastropods, annelids and crustaceans, there has been very limited research on the effects of NO on metamorphosis in bivalve shellfish.ResultsIn this paper, we investigate the effects of NO pathway inhibitors and NO donors on metamorphosis induction in larvae of the Pacific oyster,Crassostrea gigas.The nitric oxides synthase (NOS) inhibitors s-methylisothiourea hemisulfate salt (SMIS), aminoguanidine hemisulfate salt (AGH) and 7-nitroindazole (7-NI) induced metamorphosis at 75, 76 and 83% respectively, and operating in a concentration-dependent manner. Additional induction of up to 54% resulted from exposures to 1H-[1,2,4]Oxadiazole[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylyl cyclase, with which NO interacts to catalyse the synthesis of cyclic guanosine monophosphate (cGMP). Conversely, high concentrations of the NO donor sodium nitroprusside dihydrate in combination with metamorphosis inducers epinephrine, MK-801 or SMIS, significantly decreased metamorphosis, although a potential harmful effect of excessive NO unrelated to metamorphosis pathway cannot be excluded. Expression ofCgNOSalso decreased in larvae after metamorphosis regardless of the inducers used, but intensified again post-metamorphosis in spat. Fluorescent detection of NO in competent larvae with DAF-FM diacetate and localisation of the oyster nitric oxide synthaseCgNOSexpression by in-situ hybridisation showed that NO occurs primarily in two key larval structures, the velum and foot. cGMP was also detected in the foot using immunofluorescent assays, and is potentially involved in the foot’s smooth muscle relaxation.ConclusionTogether, these results suggest that the NO pathway acts as a negative regulator of metamorphosis in Pacific oyster larvae, and that NO reduction induces metamorphosis by inhibiting swimming or crawling behaviour, in conjunction with a cascade of additional neuroendocrine downstream responses. |
| Databáze: | OpenAIRE |
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