Interrelationships of chromalveolates within a broadly sampled tree of photosynthetic protists.
The Chromalveolata "supergroup" is a massive assemblage of single-celled and multicellular protists such as ciliates and kelps that remains to be substantiated in molecular trees. Recent multigene analyses place chromalveolates into two major clades, the SAR (Stramenopiles, Alveolata, and Rhizaria) and the Cryptophyta+Haptophyta. Here we determined 69 new sequences from different chromalveolates to study the interrelationships of its constituent phyla. We included in our trees, the novel groups Telonemia and Katablepharidophyta that have previously been described as chromalvoleate allies. The best phylogenetic resolution resulted from a 6-protein (actin, alpha-tubulin, beta-tubulin, cytosolic HSP70, BIP HSP70, HSP90) and a 5-protein (lacking HSP90) alignment that validated the SAR and cryptophyte+haptophyte clades with the inclusion of telonemids in the former and katablepharids in the latter. We assessed the Plastidophila hypothesis that is based on EF2 data and suggest this grouping may be explained by horizontal gene transfers involving the EF2 gene rather than indicating host relationships.
Reeb
Valérie C
VC
Department of Biology and Roy J. Carver Center for Comparative Genomics, University of Iowa, Iowa City, IA 52242, USA. valerie-reeb@uiowa.edu
Peglar
Michael T
MT
Yoon
Hwan Su
HS
Bai
Jennifer Ruoyu
JR
Wu
Min
M
Shiu
Philip
P
Grafenberg
Jessie L
JL
Reyes-Prieto
Adrian
A
Rümmele
Susanne E
SE
Gross
Jeferson
J
Bhattacharya
Debashish
D
D044785:Cryptophyta / Q000145:classification / Q000235:genetics*; D048028:DNA, Algal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D019143:Evolution, Molecular; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D048028:DNA, Algal; D004275:DNA, Ribosomal