As you might have noticed (see below), Katja (my school mate) and I are writing a seminar for a class called Interaction of organisms, a seminar on alga-animal (more specifically zooxanthella-animal) relationship. During my search I’ve come across an article that talks about fatty acids and their role in thermal stress (Berkelmans & van Oppen 2006). A certain paragraph reads like this:
Thermal tolerance among different zooxanthella types is in large part due to thermal stability of the thylakoid lipid membranes of the chloroplasts, with sensitive types having lower concentrations of saturated polyunsaturated fatty acids and greater susceptibility to attack by reactive oxygen molecules which ultimately damages host cells.
Authors basically re-wrote verbatim with, what seems at first sight, no critical thinking. I’m not sure weather or not they’ve contacted the original author, but given that the fact reads the same as in the original, I would wage a guess that they haven’t.
The original work by Tchernov et al. (2004):
“Specifically, thermally tolerant, cultures Symbiodinium clones and zooxanthellae freshly isolated from corals that did not bleach after experimental thermal stress have a markedly lower concentration of the major polyunsaturated fatty acid, (delta)6,9,12,15-cis-octadecatetraenoic acid (18:4), in relation to (delta)9-cis-octadecatetraeonic (18:1) acid, independent of the experimental temperature. The differences in the lipid profile are statistically significant at the 0,001 level (ANOVA). The higher relative concentration of the saturated polyunsaturated fatty acid enhances thermal stability in eukaryotic thylakoid membranes and simultaneously reduces the susceptibility of the membrane lipid to attack by ROS.”
I have contacted the author and he confirmed my suspicion, that what was actually meant was the RATIO between saturated and polyunsaturated fatty acids. Looks like a : or / somehow got left out. I hear it happens (too) often!
Berkelmans, R. van Oppen, M. J. H. 2006. The role of zooxanthellae in the thermal tolerance of corals: a ‘nugget of hope’ for coral reefs in an era of climate change. Proc. R. Soc. B. 273, 2305-2312.
Tchernov, D., Gorbunov, M. Y., de Vargas. C., Narayan Yadav. S., Milligan, A. J., Häggblom, M., Falkowski, P. G. 2004. Membrane lipids of symbiotic algae are diagnostic of sensitivity to thermal bleaching in corals. Proc. Natl. Acad. Sci.. 101, 13531-13535 (doi:10.101073/pnas.0402907101).