The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs
Intraspecific variation in egg size and its effects on offspring fitness is well documented in fishes. Yet whether or not differential per propagule maternal investment (egg size) can influence phenotypic diversification is little understood. Arctic charr (Salvelinus alpinus) are famed for their res...
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Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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University of Iceland, School of Engineering and Natural Sciences, Faculty of Life and Environmental Sciences
2019
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Online Access: | https://hdl.handle.net/20.500.11815/1017 |
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ftopinvisindi:oai:opinvisindi.is:20.500.11815/1017 2023-05-15T14:24:33+02:00 The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs Mikilvægi Hrognastærðar fyrir þróun fjölbreytileika hjá afbrigðum bleikju (Salvelinus Alpinus) Beck, Samantha V. Camille Leblanc Líf- og umhverfisvísindadeild (HÍ) Faculty of Life and Environmental Sciences (UI) Fiskeldis- og fiskalíffræðideild (HH) Department of Aquaculture and Fish Biology (HUC) Verkfræði- og náttúruvísindasvið (HÍ) School of Engineering and Natural Sciences (UI) Háskóli Íslands University of Iceland Háskólinn á Hólum Hólar University College 2019-01-30 https://hdl.handle.net/20.500.11815/1017 en eng University of Iceland, School of Engineering and Natural Sciences, Faculty of Life and Environmental Sciences Samantha V. Beck, 2019, The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs, PhD dissertation, Faculty of Life and Environmental Sciences, University of Iceland, 196 pp. 978-9935-9438-4-2 https://hdl.handle.net/20.500.11815/1017 info:eu-repo/semantics/openAccess Gene expression Early development Ecology Morphology Bleikja Hrogn Gen Vistkerfi Líffræði Doktorsritgerðir info:eu-repo/semantics/doctoralThesis 2019 ftopinvisindi https://doi.org/20.500.11815/1017 2022-11-18T06:51:41Z Intraspecific variation in egg size and its effects on offspring fitness is well documented in fishes. Yet whether or not differential per propagule maternal investment (egg size) can influence phenotypic diversification is little understood. Arctic charr (Salvelinus alpinus) are famed for their resource polymorphisms, whereby their degree of sympatric diversification often varies between lakes. Using a gradient of divergence, we aimed to understand how egg size influenced: (1) developmental times, (2) relative expression of genes related to growth and skeletogenesis across early-life stages, (3) craniofacial shape at hatching and first feeding, and (4) the covariance between craniofacial shape and the relative expression of genes related to growth and skeletogenesis. We found morphs to differ in egg size and egg size variation, as well their extent of egg size-mediated effects on offspring gene expression and craniofacial shape. Most striking is the higher expression of genes related to skeletogenesis at eye stage in the weakly diverged Vatnshlíðarvatn silver morph, all of which also correlated with egg size and was the only morph to have egg size-correlated differences in craniofacial shape. These results demonstrate the likely role that canalisation has played in reducing phenotypic variation in offpspring (i.e. gene expression and shape), in concert with egg size-mediated maternal effects, along a gradient of sympatric divergence. This thesis provides novel insight into the potential for early-life stage divergence of gene expression and associated shape change, alongside variation in egg size, to drive phenotypic diversification in the early evolution of resource polymorphism. Breytileiki á hrognastærð innan og milli tegunda fiska er umtalsverður og hrognastærð hefur áhrif á afkomu og hæfni afkvæma. Skilningur okkar á því hvaða áhrif eggjastærð getur haft á þroskunarferla afkvæma er aftur á móti takmarkaður. Bleikja (Salvelinus alpinus) er þekkt fyrir óvenjumikinn svipgerðarbreytileika og mismunandi ... Doctoral or Postdoctoral Thesis Arctic Arctic charr Arctic Salvelinus alpinus Opin vísindi (Iceland) Arctic Vatnshlíðarvatn ENVELOPE(-19.628,-19.628,65.517,65.517) |
institution |
Open Polar |
collection |
Opin vísindi (Iceland) |
op_collection_id |
ftopinvisindi |
language |
English |
topic |
Gene expression Early development Ecology Morphology Bleikja Hrogn Gen Vistkerfi Líffræði Doktorsritgerðir |
spellingShingle |
Gene expression Early development Ecology Morphology Bleikja Hrogn Gen Vistkerfi Líffræði Doktorsritgerðir Beck, Samantha V. The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs |
topic_facet |
Gene expression Early development Ecology Morphology Bleikja Hrogn Gen Vistkerfi Líffræði Doktorsritgerðir |
description |
Intraspecific variation in egg size and its effects on offspring fitness is well documented in fishes. Yet whether or not differential per propagule maternal investment (egg size) can influence phenotypic diversification is little understood. Arctic charr (Salvelinus alpinus) are famed for their resource polymorphisms, whereby their degree of sympatric diversification often varies between lakes. Using a gradient of divergence, we aimed to understand how egg size influenced: (1) developmental times, (2) relative expression of genes related to growth and skeletogenesis across early-life stages, (3) craniofacial shape at hatching and first feeding, and (4) the covariance between craniofacial shape and the relative expression of genes related to growth and skeletogenesis. We found morphs to differ in egg size and egg size variation, as well their extent of egg size-mediated effects on offspring gene expression and craniofacial shape. Most striking is the higher expression of genes related to skeletogenesis at eye stage in the weakly diverged Vatnshlíðarvatn silver morph, all of which also correlated with egg size and was the only morph to have egg size-correlated differences in craniofacial shape. These results demonstrate the likely role that canalisation has played in reducing phenotypic variation in offpspring (i.e. gene expression and shape), in concert with egg size-mediated maternal effects, along a gradient of sympatric divergence. This thesis provides novel insight into the potential for early-life stage divergence of gene expression and associated shape change, alongside variation in egg size, to drive phenotypic diversification in the early evolution of resource polymorphism. Breytileiki á hrognastærð innan og milli tegunda fiska er umtalsverður og hrognastærð hefur áhrif á afkomu og hæfni afkvæma. Skilningur okkar á því hvaða áhrif eggjastærð getur haft á þroskunarferla afkvæma er aftur á móti takmarkaður. Bleikja (Salvelinus alpinus) er þekkt fyrir óvenjumikinn svipgerðarbreytileika og mismunandi ... |
author2 |
Camille Leblanc Líf- og umhverfisvísindadeild (HÍ) Faculty of Life and Environmental Sciences (UI) Fiskeldis- og fiskalíffræðideild (HH) Department of Aquaculture and Fish Biology (HUC) Verkfræði- og náttúruvísindasvið (HÍ) School of Engineering and Natural Sciences (UI) Háskóli Íslands University of Iceland Háskólinn á Hólum Hólar University College |
format |
Doctoral or Postdoctoral Thesis |
author |
Beck, Samantha V. |
author_facet |
Beck, Samantha V. |
author_sort |
Beck, Samantha V. |
title |
The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs |
title_short |
The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs |
title_full |
The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs |
title_fullStr |
The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs |
title_full_unstemmed |
The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs |
title_sort |
influence of egg size for the diversification of arctic charr (salvelinus alpinus) morphs |
publisher |
University of Iceland, School of Engineering and Natural Sciences, Faculty of Life and Environmental Sciences |
publishDate |
2019 |
url |
https://hdl.handle.net/20.500.11815/1017 |
long_lat |
ENVELOPE(-19.628,-19.628,65.517,65.517) |
geographic |
Arctic Vatnshlíðarvatn |
geographic_facet |
Arctic Vatnshlíðarvatn |
genre |
Arctic Arctic charr Arctic Salvelinus alpinus |
genre_facet |
Arctic Arctic charr Arctic Salvelinus alpinus |
op_relation |
Samantha V. Beck, 2019, The influence of egg size for the diversification of Arctic charr (Salvelinus alpinus) morphs, PhD dissertation, Faculty of Life and Environmental Sciences, University of Iceland, 196 pp. 978-9935-9438-4-2 https://hdl.handle.net/20.500.11815/1017 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/20.500.11815/1017 |
_version_ |
1766296994243936256 |