Evidence map›Paper›PMID 25875483›Full record

ArticlePloS one2015

Regulatory evolution and voltage-gated ion channel expression in squid axon: selection-mutation balance and fitness cliffs.

Min Kim, Don McKinnon, Thomas MacCarthy, Barbara Rosati, David McKinnon

Abstract read
In one paragraph

Article in PloS one, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Transmural gradients in ion channel and auxiliary subunit expression.Progress in biophysics and molecular biology · 2016
    Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Min KimDepartment of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York, United States of America.
Don McKinnonInstitute of Molecular Cardiology, Stony Brook University, Stony Brook, New York, United States of America.
Thomas MacCarthyDepartment of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America.
Barbara RosatiInstitute of Molecular Cardiology, Stony Brook University, Stony Brook, New York, United States of America; Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York, United States of America.
David McKinnonDepartment of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York, United States of America; Institute of Molecular Cardiology, Stony Brook University, Stony Brook, New York, United States of America; The Department of Research, Veterans Affairs Medical Center, Northport, New York, United States of America.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

It has been suggested that optimization of either axonal conduction velocity or the energy efficiency of action potential conduction predominates in the selection of voltage-gated sodium conductance levels in the squid axon. A population genetics model of channel gene regulatory function was used to examine the role of these and other evolutionary forces on the selection of both sodium and potassium channel expression levels. In this model, the accumulating effects of mutations result in degradation of gene regulatory function, causing channel gene expression to fall to near-zero in the absence of positive selection. In the presence of positive selection, channel expression levels fall to the lowest values consistent with the selection criteria, thereby establishing a selection-mutation balance. Within the parameter space of sodium and potassium conductance values, the physiological performance of the squid axon model showed marked discontinuities associated with conduction failure and excitability. These discontinuities in physiological function may produce fitness cliffs. A fitness cliff associated with conduction failure, combined with the effects of phenotypic noise, can account for the selection of sodium conductance levels, without considering either conduction velocity or metabolic cost. A fitness cliff associated with a transition in axonal excitability, combined with phenotypic noise, can explain the selection of potassium channel expression levels. The results suggest that voltage-gated ion channel expression will fall to low levels, consistent with key functional constraints, even in the absence of positive selection for energy efficiency. Channel expression levels and individual variation in channel expression within the population can be explained by regulatory evolution in combination with genetic variation in regulatory function and phenotypic noise, without resorting to more complex mechanisms, such as activity-dependent homeostasis. Only a relatively small region of the large, nominally isofunctional parameter space for channel expression will normally be occupied, because of the effects of mutation.

Indexed as

Biological EvolutionAction PotentialsAnimalsAxonsDecapodiformesEvolution, MolecularGene Regulatory NetworksModels, GeneticMutationNeural ConductionPotassium ChannelsSodium ChannelsPotassium ChannelsSodium Channels

Identifiers

PMID25875483
PMCPMC4395378

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.