Multiple genes of apparent algal origin suggest ciliates may once have been photosynthetic. Export

@article{citeulike:2985634, abstract = {Plantae (as defined by Cavalier-Smith, 1981) [1] plastids evolved via primary endosymbiosis whereby a heterotrophic protist enslaved a photosynthetic cyanobacterium. This "primary" plastid spread into other eukaryotes via secondary endosymbiosis. An important but contentious theory in algal evolution is the chromalveolate hypothesis that posits chromists (cryptophytes, haptophytes, and stramenopiles) and alveolates (ciliates, apicomplexans, and dinoflagellates) share a common ancestor that contained a red-algal-derived "secondary" plastid [2]. Under this view, the existence of several later-diverging plastid-lacking chromalveolates such as ciliates and oomycetes would be explained by plastid loss in these lineages. To test the idea of a photosynthetic ancestry for ciliates, we used the 27,446 predicted proteins from the macronuclear genome of Tetrahymena thermophila to query prokaryotic and eukaryotic genomes. We identified 16 proteins of possible algal origin in the ciliates Tetrahymena and Paramecium tetraurelia. Fourteen of these are present in other chromalveolates. Here we compare and contrast the likely scenarios for algal-gene origin in ciliates either via multiple rounds of horizontal gene transfer (HGT) from algal prey or symbionts, or through endosymbiotic gene transfer (EGT) during a putative photosynthetic phase in their evolution.}, address = {Department of Biological Sciences and Roy J. Carver Center for Comparative Genomics, University of Iowa, Iowa City, Iowa 52242-1324.}, author = {Reyes-Prieto, A. and Moustafa, A. and Bhattacharya, D.}, citeulike-article-id = {2985634}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.cub.2008.05.042}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/18595706}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=18595706}, day = {8}, doi = {10.1016/j.cub.2008.05.042}, issn = {0960-9822}, journal = {Current biology : CB}, keywords = {algae, ciliates, endosymbiosis, photosynthesis, phylogenetics, phylogenomics}, month = {July}, number = {13}, pages = {956--962}, posted-at = {2008-07-10 18:00:45}, priority = {0}, title = {Multiple genes of apparent algal origin suggest ciliates may once have been photosynthetic.}, url = {http://dx.doi.org/10.1016/j.cub.2008.05.042}, volume = {18}, year = {2008} }

TY - JOUR ID - citeulike:2985634 L3 - citeulike-article-id:2985634 N2 - Plantae (as defined by Cavalier-Smith, 1981) [1] plastids evolved via primary endosymbiosis whereby a heterotrophic protist enslaved a photosynthetic cyanobacterium. This "primary" plastid spread into other eukaryotes via secondary endosymbiosis. An important but contentious theory in algal evolution is the chromalveolate hypothesis that posits chromists (cryptophytes, haptophytes, and stramenopiles) and alveolates (ciliates, apicomplexans, and dinoflagellates) share a common ancestor that contained a red-algal-derived "secondary" plastid [2]. Under this view, the existence of several later-diverging plastid-lacking chromalveolates such as ciliates and oomycetes would be explained by plastid loss in these lineages. To test the idea of a photosynthetic ancestry for ciliates, we used the 27,446 predicted proteins from the macronuclear genome of Tetrahymena thermophila to query prokaryotic and eukaryotic genomes. We identified 16 proteins of possible algal origin in the ciliates Tetrahymena and Paramecium tetraurelia. Fourteen of these are present in other chromalveolates. Here we compare and contrast the likely scenarios for algal-gene origin in ciliates either via multiple rounds of horizontal gene transfer (HGT) from algal prey or symbionts, or through endosymbiotic gene transfer (EGT) during a putative photosynthetic phase in their evolution. IS - 13 JF - Current biology : CB SN - 0960-9822 AD - Department of Biological Sciences and Roy J. Carver Center for Comparative Genomics, University of Iowa, Iowa City, Iowa 52242-1324. EP - 962 TI - Multiple genes of apparent algal origin suggest ciliates may once have been photosynthetic. VL - 18 SP - 956 KW - algae KW - ciliates KW - endosymbiosis KW - photosynthesis KW - phylogenetics KW - phylogenomics AU - Reyes-Prieto, A AU - Moustafa, A AU - Bhattacharya, D PY - 2008/07/08/ UR - http://dx.doi.org/10.1016/j.cub.2008.05.042 ER -