The mosaic nature of the eukaryotic nucleus.
The phylogenies for each of the protein-coding genes from the Methanococcus jannaschii genome were surveyed to determine the history of the major groups of life. For each gene, homologous sequences from other archaea, eucarya, and Gram-positive and Gram-negative bacteria were collected and aligned, and a phylogeny was reconstructed with a maximum-likelihood algorithm. The majority of significant phylogenies favor the eucarya and the archaca as sister groups. A smaller, but still substantial, portion of these significant phylogenies favor an eucarya/Gram-negative clade. These results indicate that support for the early history of life is not unequivocal. A chimeric origin of eukaryotes or an ancient, massive horizontal transfer of genes from Gram-negative bacteria to eucarya can explain many of the observed phylogenies.
Ribeiro
S
S
Department of Biology, McMaster University, Hamilton, Ontario, Canada.
Golding
G B
GB
D000429:Alcohol Oxidoreductases / Q000235:genetics; D000465:Algorithms; D001126:Arginine-tRNA Ligase / Q000235:genetics; D005057:Eukaryotic Cells; D005796:Genes; D019766:Genes, Archaeal; D005798:Genes, Bacterial; D006090:Gram-Negative Bacteria / Q000235:genetics; D006094:Gram-Positive Bacteria / Q000235:genetics; D016013:Likelihood Functions; D017017:Methanococcus / Q000235:genetics*; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014153:Transaldolase / Q000235:genetics
D000429:Alcohol Oxidoreductases; C021358:histidinol dehydrogenase; D014153:Transaldolase; D001126:Arginine-tRNA Ligase