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Inbreeding depression does not increase after exposure to a stressful environment: a test using compensatory growth

BACKGROUND: Inbreeding is often associated with a decrease in offspring fitness (‘inbreeding depression’). Moreover, it is generally assumed that the negative effects of inbreeding are exacerbated in stressful environments. This G × E interaction has been explored in many taxa under different enviro...

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Autores principales: Vega-Trejo, Regina, Head, Megan L., Jennions, Michael D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818490/
https://www.ncbi.nlm.nih.gov/pubmed/27036748
http://dx.doi.org/10.1186/s12862-016-0640-1
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author Vega-Trejo, Regina
Head, Megan L.
Jennions, Michael D.
author_facet Vega-Trejo, Regina
Head, Megan L.
Jennions, Michael D.
author_sort Vega-Trejo, Regina
collection PubMed
description BACKGROUND: Inbreeding is often associated with a decrease in offspring fitness (‘inbreeding depression’). Moreover, it is generally assumed that the negative effects of inbreeding are exacerbated in stressful environments. This G × E interaction has been explored in many taxa under different environmental conditions. These studies usually manipulate environmental conditions either in adulthood or throughout an individual’s entire life. Far fewer studies have tested how stressful environments only experienced during development subsequently influence the effects of inbreeding on adult traits. RESULTS: We experimentally manipulated the diet (control versus low food) of inbred and outbred juvenile Eastern mosquitofish (Gambusia holbrooki) for three weeks (days 7-28) to test whether experiencing a presumably stressful environment early in life influences their subsequent growth and adult phenotypes. The control diet was a standard laboratory food regime, while fish on the low food diet received less than 25 % of this amount of food. Unexpectedly, despite a large sample size (237 families, 908 offspring) and a quantified 23 % reduction in genome-wide heterozygosity in inbred offspring from matings between full-siblings (f = 0.25), neither inbreeding nor its interaction with early diet affected growth trajectories, juvenile survival or adult size. Individuals did not mitigate a poor start in life by showing ‘compensatory growth’ (i.e. faster growth once the low food treatment ended), but they showed ‘catch-up growth’ by delaying maturation. There was, however, no effect of inbreeding on the extent of catch-up growth. CONCLUSIONS: There were no detectable effects of inbreeding on growth or adult size, even on a low food diet that should elevate inbreeding depression. Thus, the long-term costs of inbreeding due to lower male reproductive success we have shown in another study appear to be unrelated to inbreeding depression for adult male size or the growth rates that are reported in the current study. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-016-0640-1) contains supplementary material, which is available to authorized users.
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spelling pubmed-48184902016-04-03 Inbreeding depression does not increase after exposure to a stressful environment: a test using compensatory growth Vega-Trejo, Regina Head, Megan L. Jennions, Michael D. BMC Evol Biol Research Article BACKGROUND: Inbreeding is often associated with a decrease in offspring fitness (‘inbreeding depression’). Moreover, it is generally assumed that the negative effects of inbreeding are exacerbated in stressful environments. This G × E interaction has been explored in many taxa under different environmental conditions. These studies usually manipulate environmental conditions either in adulthood or throughout an individual’s entire life. Far fewer studies have tested how stressful environments only experienced during development subsequently influence the effects of inbreeding on adult traits. RESULTS: We experimentally manipulated the diet (control versus low food) of inbred and outbred juvenile Eastern mosquitofish (Gambusia holbrooki) for three weeks (days 7-28) to test whether experiencing a presumably stressful environment early in life influences their subsequent growth and adult phenotypes. The control diet was a standard laboratory food regime, while fish on the low food diet received less than 25 % of this amount of food. Unexpectedly, despite a large sample size (237 families, 908 offspring) and a quantified 23 % reduction in genome-wide heterozygosity in inbred offspring from matings between full-siblings (f = 0.25), neither inbreeding nor its interaction with early diet affected growth trajectories, juvenile survival or adult size. Individuals did not mitigate a poor start in life by showing ‘compensatory growth’ (i.e. faster growth once the low food treatment ended), but they showed ‘catch-up growth’ by delaying maturation. There was, however, no effect of inbreeding on the extent of catch-up growth. CONCLUSIONS: There were no detectable effects of inbreeding on growth or adult size, even on a low food diet that should elevate inbreeding depression. Thus, the long-term costs of inbreeding due to lower male reproductive success we have shown in another study appear to be unrelated to inbreeding depression for adult male size or the growth rates that are reported in the current study. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-016-0640-1) contains supplementary material, which is available to authorized users. BioMed Central 2016-04-01 /pmc/articles/PMC4818490/ /pubmed/27036748 http://dx.doi.org/10.1186/s12862-016-0640-1 Text en © Vega-Trejo et al. 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research Article
Vega-Trejo, Regina
Head, Megan L.
Jennions, Michael D.
Inbreeding depression does not increase after exposure to a stressful environment: a test using compensatory growth
title Inbreeding depression does not increase after exposure to a stressful environment: a test using compensatory growth
title_full Inbreeding depression does not increase after exposure to a stressful environment: a test using compensatory growth
title_fullStr Inbreeding depression does not increase after exposure to a stressful environment: a test using compensatory growth
title_full_unstemmed Inbreeding depression does not increase after exposure to a stressful environment: a test using compensatory growth
title_short Inbreeding depression does not increase after exposure to a stressful environment: a test using compensatory growth
title_sort inbreeding depression does not increase after exposure to a stressful environment: a test using compensatory growth
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818490/
https://www.ncbi.nlm.nih.gov/pubmed/27036748
http://dx.doi.org/10.1186/s12862-016-0640-1
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