Aquatic Sciences Meeting, Albuquerque 2001

SS22 Strategies To Reduce Mortality in Marine and Freshwater Phytoplankton

Date: Wednesday, February 14, 2001, Time: 12:00:00 PM

Location: Acoma/Zuni/Tesuque

Casotti, R, , Stazione Zoologica di Napoli, Naples, Italy, raffa@alpha.szn.it

Mazza, S, , Stazione Zoologica di Napoli, Naples, Italy,

Ianora, A, , Stazione Zoologica di Napoli, Naples, Italy,

Miralto, A, , Stazione Zoologica di Napoli, Naples, Italy,

GROWTH AND CELL CYCLE PROGRESSION N THE DIATOM T.WEISSFLOGII IS INHIBITED BY THE DIATOM ALDEHYDE 2-TRANS-4-TRANS-DECADIENAL

It has recently been shown that diatoms produce aldehydes that inhibit copepod egg hatching rates, embryonic development in the sea urchin and even proliferation of human tumor cells (Nature 403:173). Since diatoms are a main food source for copepods, the presence of such chemicals in the food would strongly affect copepod recruitment and the transfer of carbon along the food web. The effects of one of these aldehydes, 2-trans-4-trans-decadienal, on the growth and cell cycle of the centric diatom T. weissflogii was investigated by flow cytometry. When added to the growth medium, cells stopped dividing at concentrations as low as 0.5 ug/ml, but were still alive, as shown by staining with the vital stain SYTOX. Blockage of cell growth started between 0 and 4 hours after addition of the compound. Data on the cell cycle suggest that the aldehyde blocks cell cycle progression without specifically affecting any of the cell cycle phases. Aneuploidy was observed in one case, 6 hours after addition of 5 ug/ml hours of the aldehyde. The described effects may result from inhibition of mitosis, probably through de-polymerisation of tubulin, as shown in the sea urchin (Mar. Biol. 134:147-154).

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Aquatic Sciences Meeting, Albuquerque 2001

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