Cargando…

Divergent Selection Drives Genetic Differentiation in an R2R3-MYB Transcription Factor That Contributes to Incipient Speciation in Mimulus aurantiacus

Identifying the molecular genetic basis of traits contributing to speciation is of crucial importance for understanding the ecological and evolutionary mechanisms that generate biodiversity. Despite several examples describing putative “speciation genes,” it is often uncertain to what extent these g...

Descripción completa

Detalles Bibliográficos
Autores principales: Streisfeld, Matthew A., Young, Wambui N., Sobel, James M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3605050/
https://www.ncbi.nlm.nih.gov/pubmed/23555295
http://dx.doi.org/10.1371/journal.pgen.1003385
_version_ 1782263808826277888
author Streisfeld, Matthew A.
Young, Wambui N.
Sobel, James M.
author_facet Streisfeld, Matthew A.
Young, Wambui N.
Sobel, James M.
author_sort Streisfeld, Matthew A.
collection PubMed
description Identifying the molecular genetic basis of traits contributing to speciation is of crucial importance for understanding the ecological and evolutionary mechanisms that generate biodiversity. Despite several examples describing putative “speciation genes,” it is often uncertain to what extent these genetic changes have contributed to gene flow reductions in nature. Therefore, considerable interest lies in characterizing the molecular basis of traits that actively confer reproductive isolation during the early stages of speciation, as these loci can be attributed directly to the process of divergence. In Southern California, two ecotypes of Mimulus aurantiacus are parapatric and differ primarily in flower color, with an anthocyanic, red-flowered morph in the west and an anthocyanin-lacking, yellow-flowered morph in the east. Evidence suggests that the genetic changes responsible for this shift in flower color have been essential for divergence and have become fixed in natural populations of each ecotype due to almost complete differences in pollinator preference. In this study, we demonstrate that a cis-regulatory mutation in an R2R3-MYB transcription factor results in differential regulation of enzymes in the anthocyanin biosynthetic pathway and is the major contributor to differences in floral pigmentation. In addition, molecular population genetic data show that, despite gene flow at neutral loci, divergent selection has driven the fixation of alternate alleles at this gene between ecotypes. Therefore, by identifying the genetic basis underlying ecologically based divergent selection in flower color between these ecotypes, we have revealed the ecological and functional mechanisms involved in the evolution of pre-mating isolation at the early stages of incipient speciation.
format Online
Article
Text
id pubmed-3605050
institution National Center for Biotechnology Information
language English
publishDate 2013
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-36050502013-04-03 Divergent Selection Drives Genetic Differentiation in an R2R3-MYB Transcription Factor That Contributes to Incipient Speciation in Mimulus aurantiacus Streisfeld, Matthew A. Young, Wambui N. Sobel, James M. PLoS Genet Research Article Identifying the molecular genetic basis of traits contributing to speciation is of crucial importance for understanding the ecological and evolutionary mechanisms that generate biodiversity. Despite several examples describing putative “speciation genes,” it is often uncertain to what extent these genetic changes have contributed to gene flow reductions in nature. Therefore, considerable interest lies in characterizing the molecular basis of traits that actively confer reproductive isolation during the early stages of speciation, as these loci can be attributed directly to the process of divergence. In Southern California, two ecotypes of Mimulus aurantiacus are parapatric and differ primarily in flower color, with an anthocyanic, red-flowered morph in the west and an anthocyanin-lacking, yellow-flowered morph in the east. Evidence suggests that the genetic changes responsible for this shift in flower color have been essential for divergence and have become fixed in natural populations of each ecotype due to almost complete differences in pollinator preference. In this study, we demonstrate that a cis-regulatory mutation in an R2R3-MYB transcription factor results in differential regulation of enzymes in the anthocyanin biosynthetic pathway and is the major contributor to differences in floral pigmentation. In addition, molecular population genetic data show that, despite gene flow at neutral loci, divergent selection has driven the fixation of alternate alleles at this gene between ecotypes. Therefore, by identifying the genetic basis underlying ecologically based divergent selection in flower color between these ecotypes, we have revealed the ecological and functional mechanisms involved in the evolution of pre-mating isolation at the early stages of incipient speciation. Public Library of Science 2013-03-21 /pmc/articles/PMC3605050/ /pubmed/23555295 http://dx.doi.org/10.1371/journal.pgen.1003385 Text en © 2013 Streisfeld et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Streisfeld, Matthew A.
Young, Wambui N.
Sobel, James M.
Divergent Selection Drives Genetic Differentiation in an R2R3-MYB Transcription Factor That Contributes to Incipient Speciation in Mimulus aurantiacus
title Divergent Selection Drives Genetic Differentiation in an R2R3-MYB Transcription Factor That Contributes to Incipient Speciation in Mimulus aurantiacus
title_full Divergent Selection Drives Genetic Differentiation in an R2R3-MYB Transcription Factor That Contributes to Incipient Speciation in Mimulus aurantiacus
title_fullStr Divergent Selection Drives Genetic Differentiation in an R2R3-MYB Transcription Factor That Contributes to Incipient Speciation in Mimulus aurantiacus
title_full_unstemmed Divergent Selection Drives Genetic Differentiation in an R2R3-MYB Transcription Factor That Contributes to Incipient Speciation in Mimulus aurantiacus
title_short Divergent Selection Drives Genetic Differentiation in an R2R3-MYB Transcription Factor That Contributes to Incipient Speciation in Mimulus aurantiacus
title_sort divergent selection drives genetic differentiation in an r2r3-myb transcription factor that contributes to incipient speciation in mimulus aurantiacus
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3605050/
https://www.ncbi.nlm.nih.gov/pubmed/23555295
http://dx.doi.org/10.1371/journal.pgen.1003385
work_keys_str_mv AT streisfeldmatthewa divergentselectiondrivesgeneticdifferentiationinanr2r3mybtranscriptionfactorthatcontributestoincipientspeciationinmimulusaurantiacus
AT youngwambuin divergentselectiondrivesgeneticdifferentiationinanr2r3mybtranscriptionfactorthatcontributestoincipientspeciationinmimulusaurantiacus
AT sobeljamesm divergentselectiondrivesgeneticdifferentiationinanr2r3mybtranscriptionfactorthatcontributestoincipientspeciationinmimulusaurantiacus