TY - JOUR
T1 - Cyanobacterial contribution to the genomes of the plastid-lacking protists
AU - Maruyama, Shinichiro
AU - Matsuzaki, Motomichi
AU - Misawa, Kazuharu
AU - Nozaki, Hisayoshi
N1 - Funding Information:
We thank Dr. Kenji Yagita and Dr. Takuro Endo for kindly providing the genomic DNA from N. fowleri strain Nf 66. Computation time was provided by the Super Computer System, Human Genome Center, Institute of Medical Science, University of Tokyo. This work was supported by Grants-in-Aid for Research Fellowships for Young Scientists (No.20-9894 to SM) from the Japan Society for the Promotion of Science; Creative Scientific Research (No. 16GS0304 to HN) and Scientific Research (No. 20247032 to HN) from The Ministry of Education, Culture, Sports, Science, and Technology, Japan.
PY - 2009
Y1 - 2009
N2 - Background. Eukaryotic genes with cyanobacterial ancestry in plastid-lacking protists have been regarded as important evolutionary markers implicating the presence of plastids in the early evolution of eukaryotes. Although recent genomic surveys demonstrated the presence of cyanobacterial and algal ancestry genes in the genomes of plastid-lacking protists, comparative analyses on the origin and distribution of those genes are still limited. Results. We identified 12 gene families with cyanobacterial ancestry in the genomes of a taxonomically wide range of plastid-lacking eukaryotes (Phytophthora [Chromalveolata], Naegleria [Excavata], Dictyostelium [Amoebozoa], Saccharomyces and Monosiga [Opisthokonta]) using a novel phylogenetic pipeline. The eukaryotic gene clades with cyanobacterial ancestry were mostly composed of genes from bikonts (Archaeplastida, Chromalveolata, Rhizaria and Excavata). We failed to find genes with cyanobacterial ancestry in Saccharomyces and Dictyostelium, except for a photorespiratory enzyme conserved among fungi. Meanwhile, we found several Monosiga genes with cyanobacterial ancestry, which were unrelated to other Opisthokonta genes. Conclusion. Our data demonstrate that a considerable number of genes with cyanobacterial ancestry have contributed to the genome composition of the plastid-lacking protists, especially bikonts. The origins of those genes might be due to lateral gene transfer events, or an ancient primary or secondary endosymbiosis before the diversification of bikonts. Our data also show that all genes identified in this study constitute multi-gene families with punctate distribution among eukaryotes, suggesting that the transferred genes could have survived through rounds of gene family expansion and differential reduction.
AB - Background. Eukaryotic genes with cyanobacterial ancestry in plastid-lacking protists have been regarded as important evolutionary markers implicating the presence of plastids in the early evolution of eukaryotes. Although recent genomic surveys demonstrated the presence of cyanobacterial and algal ancestry genes in the genomes of plastid-lacking protists, comparative analyses on the origin and distribution of those genes are still limited. Results. We identified 12 gene families with cyanobacterial ancestry in the genomes of a taxonomically wide range of plastid-lacking eukaryotes (Phytophthora [Chromalveolata], Naegleria [Excavata], Dictyostelium [Amoebozoa], Saccharomyces and Monosiga [Opisthokonta]) using a novel phylogenetic pipeline. The eukaryotic gene clades with cyanobacterial ancestry were mostly composed of genes from bikonts (Archaeplastida, Chromalveolata, Rhizaria and Excavata). We failed to find genes with cyanobacterial ancestry in Saccharomyces and Dictyostelium, except for a photorespiratory enzyme conserved among fungi. Meanwhile, we found several Monosiga genes with cyanobacterial ancestry, which were unrelated to other Opisthokonta genes. Conclusion. Our data demonstrate that a considerable number of genes with cyanobacterial ancestry have contributed to the genome composition of the plastid-lacking protists, especially bikonts. The origins of those genes might be due to lateral gene transfer events, or an ancient primary or secondary endosymbiosis before the diversification of bikonts. Our data also show that all genes identified in this study constitute multi-gene families with punctate distribution among eukaryotes, suggesting that the transferred genes could have survived through rounds of gene family expansion and differential reduction.
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U2 - 10.1186/1471-2148-9-197
DO - 10.1186/1471-2148-9-197
M3 - Article
C2 - 19664294
AN - SCOPUS:69949166095
VL - 9
JO - BMC Evolutionary Biology
JF - BMC Evolutionary Biology
SN - 1471-2148
IS - 1
M1 - 197
ER -