Cell cycle and cell mortality of Alexandrium minutum (Dinophyceae) under small-scale turbulence conditions

Decreased net population growth rates and cellular abundances have been observed in dinoflagellate species exposed to small-scale turbulence. Here, we investigated whether these effects were caused by alterations in the cell cycle and/or by cell mortality and, in turn, whether these two mechanisms d...

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Detalles Bibliográficos
Autor: Llavería, Gisela
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2009
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/321589
Acceso en línea:http://hdl.handle.net/10261/321589
Access Level:acceso abierto
Palabra clave:Medio Marino
Alexandrium minutum
Centro Oceanográfico de Vigo
Cell cycle
Coulter counter
dinoflagellates
flow cytometry
small-scale turbulence
mortality
turbulence
growth
Descripción
Sumario:Decreased net population growth rates and cellular abundances have been observed in dinoflagellate species exposed to small-scale turbulence. Here, we investigated whether these effects were caused by alterations in the cell cycle and/or by cell mortality and, in turn, whether these two mechanisms depended on the duration of exposure to turbulence. The study was conducted on the toxic dinoflagellate Alexandrium minutum Halim, with the same experimental design and setup used in previous studies to allow direct comparison among results. A combination of microscopy and Coulter Counter measurements allowed us to detect cell mortality, based on the biovolume of broken cells and thecae. The turbulence applied during the exponential growth phase caused an immediate transitory arrest in the G2/M phase, but significant mortality did not occur. This finding suggests that high intensities of small-scale turbulence can alter the cell division, likely affecting the correct chromosome segregation during the dinomitosis. When shaking persisted for >4 d, mortality signals and presence of anomalously swollen cells appeared, hinting at the activation of mechanisms that induce programmed cell death. Our study suggests that the sensitivity of dinoflagellates to turbulence may drive these organisms to find the most favorable (calm) conditions to complete their division cycle.