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Microevolutionary dynamics of a macroevolutionary key innovation in a Lepidopteran herbivore

BACKGROUND: A molecular population genetics understanding is central to the study of ecological and evolutionary functional genomics. Population genetics identifies genetic variation and its distribution within and among populations, it reveals the demographic history of the populations studied, and...

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Autores principales: Heidel-Fischer, Hanna M, Vogel, Heiko, Heckel, David G, Wheat, Christopher W
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2841170/
https://www.ncbi.nlm.nih.gov/pubmed/20181249
http://dx.doi.org/10.1186/1471-2148-10-60
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author Heidel-Fischer, Hanna M
Vogel, Heiko
Heckel, David G
Wheat, Christopher W
author_facet Heidel-Fischer, Hanna M
Vogel, Heiko
Heckel, David G
Wheat, Christopher W
author_sort Heidel-Fischer, Hanna M
collection PubMed
description BACKGROUND: A molecular population genetics understanding is central to the study of ecological and evolutionary functional genomics. Population genetics identifies genetic variation and its distribution within and among populations, it reveals the demographic history of the populations studied, and can provide indirect insights into historical selection dynamics. Here we use this approach to examine the demographic and selective dynamics acting of a candidate gene involved in plant-insect interactions. Previous work documents the macroevolutionary and historical ecological importance of the nitrile-specifier protein (Nsp), which facilitated the host shift of Pieridae butterflies onto Brassicales host plants ~80 Myr ago. RESULTS: Here we assess the microevolutionary dynamics of the Nsp gene by studying the within and among-population variation at Nsp and reference genes in the butterfly Pieris rapae (Small Cabbage White). Nsp exhibits unexpectedly high amounts of amino acid polymorphism, unequally distributed across the gene. The vast majority of genetic variation exists within populations, with little to no genetic differentiation among four populations on two continents. A comparison of synonymous and nonsynonymous substitutions in 70 randomly chosen genes among P. rapae and its close relative Pieris brassicae (Large Cabbage White) finds Nsp to have a significantly relaxed functional constraint compared to housekeeping genes. We find strong evidence for a recent population expansion and no role for strong purifying or directional selection upon the Nsp gene. CONCLUSIONS: The microevolutionary dynamics of the Nsp gene in P. rapae are dominated by recent population expansion and variation in functional constraint across the repeated domains of the Nsp gene. While the high amounts of amino acid diversity suggest there may be significant functional differences among allelic variants segregating within populations, indirect tests of selection could not conclusively identify a signature of historical selection. The importance of using this information for planning future studies of potential performance and fitness consequences of the observed variation is discussed.
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spelling pubmed-28411702010-03-18 Microevolutionary dynamics of a macroevolutionary key innovation in a Lepidopteran herbivore Heidel-Fischer, Hanna M Vogel, Heiko Heckel, David G Wheat, Christopher W BMC Evol Biol Research article BACKGROUND: A molecular population genetics understanding is central to the study of ecological and evolutionary functional genomics. Population genetics identifies genetic variation and its distribution within and among populations, it reveals the demographic history of the populations studied, and can provide indirect insights into historical selection dynamics. Here we use this approach to examine the demographic and selective dynamics acting of a candidate gene involved in plant-insect interactions. Previous work documents the macroevolutionary and historical ecological importance of the nitrile-specifier protein (Nsp), which facilitated the host shift of Pieridae butterflies onto Brassicales host plants ~80 Myr ago. RESULTS: Here we assess the microevolutionary dynamics of the Nsp gene by studying the within and among-population variation at Nsp and reference genes in the butterfly Pieris rapae (Small Cabbage White). Nsp exhibits unexpectedly high amounts of amino acid polymorphism, unequally distributed across the gene. The vast majority of genetic variation exists within populations, with little to no genetic differentiation among four populations on two continents. A comparison of synonymous and nonsynonymous substitutions in 70 randomly chosen genes among P. rapae and its close relative Pieris brassicae (Large Cabbage White) finds Nsp to have a significantly relaxed functional constraint compared to housekeeping genes. We find strong evidence for a recent population expansion and no role for strong purifying or directional selection upon the Nsp gene. CONCLUSIONS: The microevolutionary dynamics of the Nsp gene in P. rapae are dominated by recent population expansion and variation in functional constraint across the repeated domains of the Nsp gene. While the high amounts of amino acid diversity suggest there may be significant functional differences among allelic variants segregating within populations, indirect tests of selection could not conclusively identify a signature of historical selection. The importance of using this information for planning future studies of potential performance and fitness consequences of the observed variation is discussed. BioMed Central 2010-02-24 /pmc/articles/PMC2841170/ /pubmed/20181249 http://dx.doi.org/10.1186/1471-2148-10-60 Text en Copyright ©2010 Heidel-Fischer et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research article
Heidel-Fischer, Hanna M
Vogel, Heiko
Heckel, David G
Wheat, Christopher W
Microevolutionary dynamics of a macroevolutionary key innovation in a Lepidopteran herbivore
title Microevolutionary dynamics of a macroevolutionary key innovation in a Lepidopteran herbivore
title_full Microevolutionary dynamics of a macroevolutionary key innovation in a Lepidopteran herbivore
title_fullStr Microevolutionary dynamics of a macroevolutionary key innovation in a Lepidopteran herbivore
title_full_unstemmed Microevolutionary dynamics of a macroevolutionary key innovation in a Lepidopteran herbivore
title_short Microevolutionary dynamics of a macroevolutionary key innovation in a Lepidopteran herbivore
title_sort microevolutionary dynamics of a macroevolutionary key innovation in a lepidopteran herbivore
topic Research article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2841170/
https://www.ncbi.nlm.nih.gov/pubmed/20181249
http://dx.doi.org/10.1186/1471-2148-10-60
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