Understanding maturity: insights into the mechanisms underpinning maturity in gadoids
Marked shifts in the life history traits of fish have been reported in many exploited fish stocks, with a particular trend towards decreasing size and age at maturity. Though other environmental and behavioural factors have been implicated, the key driver of these changes links to fishing pressure,...
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University of Stirling
2016
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Online Access: | http://hdl.handle.net/1893/25265 http://dspace.stir.ac.uk/bitstream/1893/25265/1/AliceDoyle_Thesis_v2.pdf |
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ftunivstirling:oai:dspace.stir.ac.uk:1893/25265 2023-05-15T15:27:10+02:00 Understanding maturity: insights into the mechanisms underpinning maturity in gadoids Doyle, Alice Davie, Andrew Wright, Peter 2016-06 application/pdf http://hdl.handle.net/1893/25265 http://dspace.stir.ac.uk/bitstream/1893/25265/1/AliceDoyle_Thesis_v2.pdf en eng University of Stirling http://hdl.handle.net/1893/25265 http://dspace.stir.ac.uk/bitstream/1893/25265/1/AliceDoyle_Thesis_v2.pdf 2018-12-31 I require time to write articles for publication 2019-01-01 Gadoid cod maturity Eya3 photoperiod photoneuroendocrine BPG Atlantic cod Gadiformes Photoperiodism Thesis or Dissertation Doctoral Doctor of Philosophy 2016 ftunivstirling 2022-06-13T18:41:43Z Marked shifts in the life history traits of fish have been reported in many exploited fish stocks, with a particular trend towards decreasing size and age at maturity. Though other environmental and behavioural factors have been implicated, the key driver of these changes links to fishing pressure, through both the direct selective effects of fishing itself, and indirectly through the manipulation of important biological and environmental factors. Although reproduction itself has been well described in teleosts, the mechanisms of environmental and endogenous entrainment of maturation remain unclear and it was the principal aim of this thesis to improve current understanding of these systems in gadoids. Photoperiod has been identified as the strongest environmental cue for entraining seasonal behaviours, including seasonal reproduction. Over the last decade, several of the key drivers involved in the photoneuroendocrine cascade have been elucidated in mammals and birds, with the Eya3 pathway merging as an important mechanism for entraining maturation. However, little is yet known of their influence on maturation in fish. In the first study, the photoperiodic regulation of the Eya3-Tshβ-Dio2 cascade was analysed in Atlantic cod exposed to either continuous light (reproductive inhibition) or simulated natural photoperiod (reproductive stimulation) from July to December. Monthly expression was measured through QPCR, demonstrating a strong activation of pituitary Eya3 under declining photoperiod. As this coincided with the onset of secondary gametogenesis, these results suggest that Eya3 may play a stimulatory role in the photoneuroendocrine cascade of Atlantic cod. Although photoperiod represents the most reliable and noise free proximate signal to entrain the reproductive process, it is clear that a minimum growth and energetic state must be reached for maturation to progress. This directed the second line of study – a series of diet restriction trials on haddock and cod designed to investigate the influence of ... Doctoral or Postdoctoral Thesis atlantic cod University of Stirling: Stirling Digital Research Repository |
institution |
Open Polar |
collection |
University of Stirling: Stirling Digital Research Repository |
op_collection_id |
ftunivstirling |
language |
English |
topic |
Gadoid cod maturity Eya3 photoperiod photoneuroendocrine BPG Atlantic cod Gadiformes Photoperiodism |
spellingShingle |
Gadoid cod maturity Eya3 photoperiod photoneuroendocrine BPG Atlantic cod Gadiformes Photoperiodism Doyle, Alice Understanding maturity: insights into the mechanisms underpinning maturity in gadoids |
topic_facet |
Gadoid cod maturity Eya3 photoperiod photoneuroendocrine BPG Atlantic cod Gadiformes Photoperiodism |
description |
Marked shifts in the life history traits of fish have been reported in many exploited fish stocks, with a particular trend towards decreasing size and age at maturity. Though other environmental and behavioural factors have been implicated, the key driver of these changes links to fishing pressure, through both the direct selective effects of fishing itself, and indirectly through the manipulation of important biological and environmental factors. Although reproduction itself has been well described in teleosts, the mechanisms of environmental and endogenous entrainment of maturation remain unclear and it was the principal aim of this thesis to improve current understanding of these systems in gadoids. Photoperiod has been identified as the strongest environmental cue for entraining seasonal behaviours, including seasonal reproduction. Over the last decade, several of the key drivers involved in the photoneuroendocrine cascade have been elucidated in mammals and birds, with the Eya3 pathway merging as an important mechanism for entraining maturation. However, little is yet known of their influence on maturation in fish. In the first study, the photoperiodic regulation of the Eya3-Tshβ-Dio2 cascade was analysed in Atlantic cod exposed to either continuous light (reproductive inhibition) or simulated natural photoperiod (reproductive stimulation) from July to December. Monthly expression was measured through QPCR, demonstrating a strong activation of pituitary Eya3 under declining photoperiod. As this coincided with the onset of secondary gametogenesis, these results suggest that Eya3 may play a stimulatory role in the photoneuroendocrine cascade of Atlantic cod. Although photoperiod represents the most reliable and noise free proximate signal to entrain the reproductive process, it is clear that a minimum growth and energetic state must be reached for maturation to progress. This directed the second line of study – a series of diet restriction trials on haddock and cod designed to investigate the influence of ... |
author2 |
Davie, Andrew Wright, Peter |
format |
Doctoral or Postdoctoral Thesis |
author |
Doyle, Alice |
author_facet |
Doyle, Alice |
author_sort |
Doyle, Alice |
title |
Understanding maturity: insights into the mechanisms underpinning maturity in gadoids |
title_short |
Understanding maturity: insights into the mechanisms underpinning maturity in gadoids |
title_full |
Understanding maturity: insights into the mechanisms underpinning maturity in gadoids |
title_fullStr |
Understanding maturity: insights into the mechanisms underpinning maturity in gadoids |
title_full_unstemmed |
Understanding maturity: insights into the mechanisms underpinning maturity in gadoids |
title_sort |
understanding maturity: insights into the mechanisms underpinning maturity in gadoids |
publisher |
University of Stirling |
publishDate |
2016 |
url |
http://hdl.handle.net/1893/25265 http://dspace.stir.ac.uk/bitstream/1893/25265/1/AliceDoyle_Thesis_v2.pdf |
genre |
atlantic cod |
genre_facet |
atlantic cod |
op_relation |
http://hdl.handle.net/1893/25265 http://dspace.stir.ac.uk/bitstream/1893/25265/1/AliceDoyle_Thesis_v2.pdf |
op_rights |
2018-12-31 I require time to write articles for publication 2019-01-01 |
_version_ |
1766357625242386432 |