Highly divergent SSU rRNA genes found in the marine ciliates Myrionecta rubra and Mesodinium pulex

被引:47
作者
Johnson, MD
Tengs, T
Oldach, DW
Delwiche, CF
Stoecker, DK
机构
[1] Univ Maryland, Horn Point Environm Lab, Ctr Environm Sci, Cambridge, MD 21613 USA
[2] Univ Maryland, Sch Med, Inst Human Virol, Baltimore, MD 21201 USA
[3] Univ Maryland, Dept Cell Biol & Mol Genet Plant Biol, College Pk, MD 20742 USA
基金
美国国家科学基金会;
关键词
D O I
10.1078/1434461041844222
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
Myrionecta rubra and Mesodinium pulex are among the most commonly encountered planktonic ciliates in coastal marine and estuarine regions throughout the world. Despite their widespread distribution, both ciliates have received little attention by taxonomists. In order to better understand the phylogenetic position of these ciliates, we determined the SSU rRNA gene sequence from cultures of M. rubra and M. pulex. Partial sequence data were also generated from isolated cells of M. rubra from Chesapeake Bay. The M. rubra and M. pulex sequences were very divergent from all other ciliates, but shared a branch with 100% bootstrap support. Both species had numerous deletions and substitutions in their SSU rRNA gene, resulting in a long branch for the clade. This made the sequences prone to spurious phylogenetic affiliations when using simple phylogenetic methods. Maximum likelihood analysis placed M. rubra and M. pulex on the basal ciliate branch, following removal of ambiguously aligned regions. Fluorescent in situ hybridization probes were used with confocal laser scanning microscopy to confirm that these divergent sequences were both expressed in the cytoplasm and nucleolus of M. rubra and M. pulex. We found that our sequence data matched several recently discovered unidentified eukaryotes in Genbank from diverse marine habitats, all of which had apparently been misattributed to highly divergent amoeboid organisms.
引用
收藏
页码:347 / 359
页数:13
相关论文
共 46 条
[1]   BASIC LOCAL ALIGNMENT SEARCH TOOL [J].
ALTSCHUL, SF ;
GISH, W ;
MILLER, W ;
MYERS, EW ;
LIPMAN, DJ .
JOURNAL OF MOLECULAR BIOLOGY, 1990, 215 (03) :403-410
[2]  
[Anonymous], 1992, MacClade: Analysis of phylogeny and character evolution
[3]   Evolution of histone H4 and H3 genes in different ciliate lineages [J].
Bernhard, D ;
Schlegel, M .
JOURNAL OF MOLECULAR EVOLUTION, 1998, 46 (03) :344-354
[4]  
Darwin C., 1839, Journal of Researches into the Natural History and Geology of the Countries Visited during the Voyage of H.M.S. Beagle
[5]   Novel kingdom-level eukaryotic diversity in anoxic environments [J].
Dawson, SC ;
Pace, NR .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2002, 99 (12) :8324-8329
[6]   A STUDY OF FEEDING IN PREDACIOUS CILIATES USING PREY CILIATES LABELED WITH FLUORESCENT MICROSPHERES [J].
DOLAN, JR ;
COATS, DW .
JOURNAL OF PLANKTON RESEARCH, 1991, 13 (03) :609-627
[7]  
FOISSNER W, 1999, LANDESAMTES WASERWIR
[8]  
Guillard R. R. L., 1975, CULTURE MARINE INVER, P26, DOI DOI 10.1007/978-1-4615-8714-9_3
[9]   Cryptophyte algae are robbed of their organelles by the marine ciliate Mesodinium rubrum [J].
Gustafson, DE ;
Stoecker, DK ;
Johnson, MD ;
Van Heukelem, WF ;
Sneider, K .
NATURE, 2000, 405 (6790) :1049-1052
[10]   OBSERVATIONS ON ULTRASTRUCTURE OF CRYPTOMONAD ENDOSYMBIONT OF RED-WATER CILIATE MESODINIUM-RUBRUM [J].
HIBBERD, DJ .
JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM, 1977, 57 (01) :45-&