Oteobacteria). The evolutionary history deduced here based on signature sequences in some of the most highly conserved protein sequences in the biota is in contrast to the rather confusing picture that seems to be emerging from other analyses of the completed bacterial genomes (21, 50, 68, 130, 143, 144, 182, 191, 255). However, as has been pointed out (50, 143, 144, 182), of the large number of s
Distinction within prokaryotes, formingthe primary taxonomic division within them, which is supported by both molecular sequence data and morphological features, is of the monoderm prokaryotes (Monodermata, i.e., those bounded by a single cell membrane) and the diderm prokaryotes (Didermata, i.e., those bounded by inner and outer cell membranes defining a periplasmic compartment). In that sense, b
Karyotic cell nucleus and endomembrane system as per the chimeric model. The key event in the origin of the eukaryotic cell is postulated to be a symbiotic association between a gram-negative eubacterium (from the proteobacteria-1 group) and likely an "eocyte" archaebacterium. This association led to the loss of the outer membrane from the gram-negative bacterium (not shown). As the membrane of th
Distinction within prokaryotes, formingthe primary taxonomic division within them, which is supported by both molecular sequence data and morphological features, is of the monoderm prokaryotes (Monodermata, i.e., those bounded by a single cell membrane) and the diderm prokaryotes (Didermata, i.e., those bounded by inner and outer cell membranes defining a periplasmic compartment). In that sense, b
Distinction within prokaryotes, formingthe primary taxonomic division within them, which is supported by both molecular sequence data and morphological features, is of the monoderm prokaryotes (Monodermata, i.e., those bounded by a single cell membrane) and the diderm prokaryotes (Didermata, i.e., those bounded by inner and outer cell membranes defining a periplasmic compartment). In that sense, b
Distinction within prokaryotes, formingthe primary taxonomic division within them, which is supported by both molecular sequence data and morphological features, is of the monoderm prokaryotes (Monodermata, i.e., those bounded by a single cell membrane) and the diderm prokaryotes (Didermata, i.e., those bounded by inner and outer cell membranes defining a periplasmic compartment). In that sense, b
Archaebacteria but instead was a chimera formed by fusion and integration of the genomes of an archaebacterium and a gram-negative bacterium. The available data indicate that the primary fusion event that gave rise to the ancestral eukaryotic cell was unique and that it was very probably distinct from (and preceded) the one that gave rise to mitochondria and hydrogenosomes. These results provide e