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The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape

BACKGROUND: Inter-population distance and differences in breeding times are barriers to reproduction that can contribute to genotypic differentiation between populations. Temporal changes in environmental conditions and local selective processes can further contribute to the establishment of reprodu...

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Autores principales: Rossetto, Maurizio, Thurlby, Katie AG, Offord, Catherine A, Allen, Chris B, Weston, Peter H
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3112089/
https://www.ncbi.nlm.nih.gov/pubmed/21586178
http://dx.doi.org/10.1186/1471-2148-11-126
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author Rossetto, Maurizio
Thurlby, Katie AG
Offord, Catherine A
Allen, Chris B
Weston, Peter H
author_facet Rossetto, Maurizio
Thurlby, Katie AG
Offord, Catherine A
Allen, Chris B
Weston, Peter H
author_sort Rossetto, Maurizio
collection PubMed
description BACKGROUND: Inter-population distance and differences in breeding times are barriers to reproduction that can contribute to genotypic differentiation between populations. Temporal changes in environmental conditions and local selective processes can further contribute to the establishment of reproductive barriers. Telopea speciosissima (Proteaceae) is an excellent subject for studying the effect of geographic, edaphic and phenological heterogeneity on genotypic differentiation because previous studies show that these factors are correlated with morphological variation. Molecular, morphological and environmental datasets were combined to characterise the relative influence of these factors on inter-population differentiation, and Bayesian analyses were used to investigate current levels of admixture between differentiated genomes. RESULTS: A landscape genetic approach involving molecular and morphological analyses identified three endpoints of differentiated population groups: coastal, upland and southern. The southern populations, isolated from the other populations by an edaphic barrier, show low migration and no evidence of admixture with other populations. Amongst the northern populations, coastal and upland populations are connected along a skewed altitudinal gradient by genetically intermediate populations. The strong association between temperature and flowering time in Telopea speciosissima was shown to maintain a temporally unstable reproductive barrier between coastal and upland populations. CONCLUSIONS: Substrate-mediated allopatry appears to be responsible for long-term genetic isolation of the southern populations. However, the temperature-dependent reproductive barrier between upland and coastal populations bears the genetic signature of temporal adjustments. The extreme climatic events of the last glacial maximum are likely to have caused more complete allochronic isolation between upland and coastal populations, as well as exerting increased selective pressure upon local genomes. However, at intermediate altitudes, current climatic conditions allow for the incorporation of alleles from previously distinct genomes, generating new, intermediate genomic assemblages and possibly increasing overall adaptive potential.
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spelling pubmed-31120892011-06-11 The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape Rossetto, Maurizio Thurlby, Katie AG Offord, Catherine A Allen, Chris B Weston, Peter H BMC Evol Biol Research Article BACKGROUND: Inter-population distance and differences in breeding times are barriers to reproduction that can contribute to genotypic differentiation between populations. Temporal changes in environmental conditions and local selective processes can further contribute to the establishment of reproductive barriers. Telopea speciosissima (Proteaceae) is an excellent subject for studying the effect of geographic, edaphic and phenological heterogeneity on genotypic differentiation because previous studies show that these factors are correlated with morphological variation. Molecular, morphological and environmental datasets were combined to characterise the relative influence of these factors on inter-population differentiation, and Bayesian analyses were used to investigate current levels of admixture between differentiated genomes. RESULTS: A landscape genetic approach involving molecular and morphological analyses identified three endpoints of differentiated population groups: coastal, upland and southern. The southern populations, isolated from the other populations by an edaphic barrier, show low migration and no evidence of admixture with other populations. Amongst the northern populations, coastal and upland populations are connected along a skewed altitudinal gradient by genetically intermediate populations. The strong association between temperature and flowering time in Telopea speciosissima was shown to maintain a temporally unstable reproductive barrier between coastal and upland populations. CONCLUSIONS: Substrate-mediated allopatry appears to be responsible for long-term genetic isolation of the southern populations. However, the temperature-dependent reproductive barrier between upland and coastal populations bears the genetic signature of temporal adjustments. The extreme climatic events of the last glacial maximum are likely to have caused more complete allochronic isolation between upland and coastal populations, as well as exerting increased selective pressure upon local genomes. However, at intermediate altitudes, current climatic conditions allow for the incorporation of alleles from previously distinct genomes, generating new, intermediate genomic assemblages and possibly increasing overall adaptive potential. BioMed Central 2011-05-18 /pmc/articles/PMC3112089/ /pubmed/21586178 http://dx.doi.org/10.1186/1471-2148-11-126 Text en Copyright ©2011 Rossetto 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
Rossetto, Maurizio
Thurlby, Katie AG
Offord, Catherine A
Allen, Chris B
Weston, Peter H
The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape
title The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape
title_full The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape
title_fullStr The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape
title_full_unstemmed The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape
title_short The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape
title_sort impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3112089/
https://www.ncbi.nlm.nih.gov/pubmed/21586178
http://dx.doi.org/10.1186/1471-2148-11-126
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