Fabrea salina

PROTOZOANS Ciliate, Fabrea salina held in seawater Bioconcentration factor (volume/volume basis) of 39... 

Two Case Studies Fabrea Salina Ophryoglena Flava. .. 122-10... 

There is also some evidence that a rhodopsin-hke molecule could be the photoreceptor pigment for phototaxis in Fabrea salina, as will be discussed below. 

Fabrea salina is a heterotrich marine ciliate found only in concentrated saltwater that actively swims along a left-handed heUx. It belongs to the same order as the photomotile ciliates Stentor coeruleus and Blepharisma japonicum, but it is different from them in that it is not apparently pigmented. The cells... 

FIGURE 122.3 A view of Fabrea salina taken under optic microscope (original magnification x 200) the adoral zone of membranelles and the digestive vacuoles are clearly visible. 

FIGURE 122.4 Action spectrum for the positive phototaxis in Fabrea salina. 

There are, however, other pieces of evidence that may indirectly suggest a role for a rhodopsin photoreceptor in Fabrea salina. In fact, preHminary experiments have shown that phototaxis is drastically reduced in the presence of hydroxylamine, which is known to interfere with the retinal-lysine binding in rhodopsins, and is strongly affected in the presence of zaprinast, a specific inhibitor of the phosphodiesterase known to be an essential component of the sensory transduction in vertebrate vision. In both cases, cell motflity is not affected by the presence of the drugs. 

Repak, A.J., Suitabihty of selected bacteria and yeasts in growing the estuarian heterotrich cihate Fabrea salina (Henneguy), /. Protozoal, 23, 219,1986. 

Marangoni, R., Preosti, G., and Colombetti, G., Phototactic orientation mechanism in the ciUate Fabrea salina, as inferred from numerical simulations,/. Photochem. Photobiol B, 54, 185, 2000. 

Marangoni, R., Gobbi, L., Verni, E, Albertini, G., and Colombetti, G., Pigment granules and hyperycin-Hke fluorescence in the marine cihate Fabrea salina, Acta Protozoal, 35, 177, 1996. 

Podesta, A., Marangoni, R., ViUani, C., and Colombetti, G., A rhodopsin-hke molecule on the plasma-membrane of Fabrea salina, J. Eukaryot. Microbiol, 41, 565,1994. 

BoscareUi, C., Bettini, R, Marangoni, R., Colombetti, G., and Buiatti, M., Identification of a rhodopsin-like gene sequence in the dhate Fabrea salina, in From Structure to Information in Sensory System, Xaddei-Ferretti, C. and Musio, C., Eds., World Sdentific, Singapore, 1998. 

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