RRC ID 46899
著者 Yamaguchi M, Mori Y, Kozuka Y, Okada H, Uematsu K, Tame A, Furukawa H, Maruyama T, Worman CO, Yokoyama K.
タイトル Prokaryote or eukaryote? A unique microorganism from the deep sea.
ジャーナル J Electron Microsc (Tokyo)
Abstract There are only two kinds of organisms on the Earth: prokaryotes and eukaryotes. Although eukaryotes are considered to have evolved from prokaryotes, there were no previously known intermediate forms between them. The differences in their cellular structures are so vast that the problem of how eukaryotes could have evolved from prokaryotes is one of the greatest enigmas in biology. Here, we report a unique organism with cellular structures appearing to have intermediate features between prokaryotes and eukaryotes, which was discovered in the deep sea off the coast of Japan using electron microscopy and structome analysis. The organism was 10 µm long and 3 µm in diameter, having >100 times the volume of Escherichia coli. It had a large 'nucleoid', consisting of naked DNA fibers, with a single nucleoid membrane and endosymbionts that resemble bacteria, but no mitochondria. Because this organism appears to be a life form distinct from both prokaryotes and eukaryotes but similar to eukaryotes, we named this unique microorganism the 'Myojin parakaryote' with the scientific name of Parakaryon myojinensis ('next to (eu)karyote from Myojin') after the discovery location and its intermediate morphology. The existence of this organism is an indication of a potential evolutionary path between prokaryotes and eukaryotes.
巻・号 61(6)
ページ 423-31
公開日 2012-1-1
DOI 10.1093/jmicro/dfs062
PII dfs062
PMID 23024290
MeSH Aquatic Organisms* Biological Evolution* Eukaryotic Cells* Phylogeny* Prokaryotic Cells*
引用数 16
WOS 分野 MICROSCOPY
リソース情報
病原微生物