TY - JOUR
T1 - Alternating terminal electron-acceptors at the basis of symbiogenesis
T2 - How oxygen ignited eukaryotic evolution
AU - Speijer, Dave
N1 - Publisher Copyright: © 2017 The Authors. BioEssays Published by WILEY Periodicals, Inc.
PY - 2017/2/1
Y1 - 2017/2/1
N2 - What kind of symbiosis between archaeon and bacterium gave rise to their eventual merger at the origin of the eukaryotes? I hypothesize that conditions favouring bacterial uptake were based on exchange of intermediate carbohydrate metabolites required by recurring changes in availability and use of the two different terminal electron chain acceptors, the bacterial one being oxygen. Oxygen won, and definitive loss of the archaeal membrane potential allowed permanent establishment of the bacterial partner as the proto-mitochondrion, further metabolic integration and highly efficient ATP production. This represents initial symbiogenesis, when crucial eukaryotic traits arose in response to the archaeon-bacterium merger. The attendant generation of internal reactive oxygen species (ROS) gave rise to a myriad of further eukaryotic adaptations, such as extreme mitochondrial genome reduction, nuclei, peroxisomes and meiotic sex. Eukaryotic origins could have started with shuffling intermediate metabolites as is still essential today.
AB - What kind of symbiosis between archaeon and bacterium gave rise to their eventual merger at the origin of the eukaryotes? I hypothesize that conditions favouring bacterial uptake were based on exchange of intermediate carbohydrate metabolites required by recurring changes in availability and use of the two different terminal electron chain acceptors, the bacterial one being oxygen. Oxygen won, and definitive loss of the archaeal membrane potential allowed permanent establishment of the bacterial partner as the proto-mitochondrion, further metabolic integration and highly efficient ATP production. This represents initial symbiogenesis, when crucial eukaryotic traits arose in response to the archaeon-bacterium merger. The attendant generation of internal reactive oxygen species (ROS) gave rise to a myriad of further eukaryotic adaptations, such as extreme mitochondrial genome reduction, nuclei, peroxisomes and meiotic sex. Eukaryotic origins could have started with shuffling intermediate metabolites as is still essential today.
KW - FADH/NADH ratio
KW - LECA
KW - eukaryotic evolution
KW - genome reduction
KW - mitochondria
KW - oxygen radicals
KW - symbiogenesis
UR - http://www.scopus.com/inward/record.url?scp=85008190908&partnerID=8YFLogxK
U2 - https://doi.org/10.1002/bies.201600174
DO - https://doi.org/10.1002/bies.201600174
M3 - Article
C2 - 28054713
SN - 0265-9247
VL - 39
JO - BioEssays
JF - BioEssays
IS - 2
M1 - 1600174
ER -