@article {6662, title = {Temperature patterns and mechanisms influencing coral bleaching during the 2016 El Ni{\~n}o}, journal = {Nature Climate Change}, volume = {9}, year = {2019}, pages = {845-851}, abstract = {Under extreme heat stress, corals expel their symbiotic algae and colour (that is, {\textquoteleft}bleaching{\textquoteright}), which often leads to widespread mortality. Predicting the large-scale environmental conditions that reinforce or mitigate coral bleaching remains unresolved and limits strategic conservation actions1,2. Here we assessed coral bleaching at 226 sites and 26 environmental variables that represent different mechanisms of stress responses from East Africa to Fiji through a coordinated effort to evaluate the coral response to the 2014{\textendash}2016 El Ni{\~n}o/Southern Oscillation thermal anomaly. We applied common time-series methods to study the temporal patterning of acute thermal stress and evaluated the effectiveness of conventional and new sea surface temperature metrics and mechanisms in predicting bleaching severity. The best models indicated the importance of peak hot temperatures, the duration of cool temperatures and temperature bimodality, which explained 50\% of the variance, compared to the common degree-heating week temperature index that explained only 9\%. Our findings suggest that the threshold concept as a mechanism to explain bleaching alone was not as powerful as the multidimensional interactions of stresses, which include the duration and temporal patterning of hot and cold temperature extremes relative to average local conditions. {\textcopyright} 2019, The Author(s), under exclusive licence to Springer Nature Limited.}, keywords = {Algae, Anthozoa}, issn = {1758678X}, doi = {10.1038/s41558-019-0576-8}, url = {https://www.nature.com/articles/s41558-019-0576-8}, author = {McClanahan, T.R. and Darling, E.S. and Maina, J.M. and Muthiga, N.A. and D{\textquoteright}agata, S. and Jupiter, S.D. and Arthur, R. and Wilson, S.K. and Mangubhai, S. and Nand, Y. and Ussi, A.M. and Humphries, A.T. and Patankar, V.J. and Mireille M.M. Guillaume and Philippe Keith and Shedrawi, G. and Julius, P. and Grimsditch, G. and Ndagala, J. and Leblond, J.} } @article {3267, title = {Evolution of Vacuolar Pyrophosphatases and Vacuolar H+-Atpases in Diatoms}, journal = {Journal of Marine Science and Technology}, volume = {22}, year = {2014}, month = {Feb}, pages = {50-59}, abstract = {

To cope with changing environments and maintain optimal metabolic conditions, the control of the intracellular proton gradients has to be tightly regulated. Among the important proton pumps, vacuolar H^+-ATPases (V-ATPases) and H^+-translocating pyrophosphatases (H^+-PPases) were found to be involved in a number of physiological processes, and shown to be regulated at the expression level and to exhibit specific sub-cellular localizations. Studies of the role of these transporters are relatively scarce in algae and nearly absent in diatoms. Phylogenetic analyses disclose that diatoms, with both K^+-dependent and K^+-independent membrane integral pyrophosphatases, including proteins with high homology with a novel class of Na^+,H^+-PPases. Analyses of Phaeodactylum tricornutum EST libraries show that the gene putatively encoding a Na^+,H^+-PPase is over-expressed in urea adapted condition. Genome-wide investigations of the reservoir of V-ATPases encoding subunits demonstrate that diatoms display an expended number of genes encoding for the proteolipid subunits c of the V0 subcomplex. Preliminary localization studies show that one of V0-c subunits is associated to the endoplasmic reticulum membrane in P. tricornutum. Altogether our data highlight that the combination of comparative and functional genomic approaches reach promises to provide new information to the roles of membrane proton pumps in diatoms.

}, keywords = {Algae, endoplasmic reticulum, H^+-PPases, V-ATPases, vacuole}, issn = {1023-2796}, doi = {10.6119/JMST-013-0829-1}, author = {Adrien Bussard and Pascal Jean Lopez} }