title: Sterol biosynthesis and prokaryotes-to-eukaryotes evolution.
abstract: It has been widely accepted that there exists a correlation between prokaryotes-to-eukaryotes evolution and atmospheric oxygen rise. However, it is a great challenge to elucidate the mechanisms underlying the correlation. Considering the facts that cellular communication of eukaryotes depends largely on membrane functions (e.g., endo- and exocytosis) and sterols play a key role in fulfilling these functions, we propose that the biosynthesis of sterols represents a critical step in the prokaryotes-to-eukaryotes evolution. Indeed, sterol biosynthesis is nearly ubiquitous among eukaryotes, but is generally excluded by prokaryotes. More importantly, during the biosynthesis of sterols, oxygen is absolutely required. Therefore, the missing link between prokaryotes-to-eukaryotes evolution and atmospheric oxygen rise is likely to reside in, at least in part, sterol biosynthesis, i.e., high atmospheric oxygen concentration facilitates the generation of sterols and thus benefits the birth of complex organisms.
authors.affiliation: Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Center for Advanced Study, Shandong University of Technology, Zibo 255049, PR China.
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Chen
authors.forename: Guang-Zhong
authors.initials: GZ
authors.lastname: Wang
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Zhang
mesh_terms: D000818:Animals; D005057:Eukaryotic Cells / Q000378:metabolism*; D019143:Evolution, Molecular; D006801:Humans; D019751:Intramolecular Transferases / Q000235:genetics / Q000378:metabolism; D011387:Prokaryotic Cells / Q000378:metabolism*; D013261:Sterols / Q000096:biosynthesis*
chemical_list: D013261:Sterols; D019751:Intramolecular Transferases; C021924:lanosterol synthase