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Analysis of the source of aggressiveness in gamecocks

Although the fighting behaviour in gamecocks has evolved because of artificial selection, it is unknown whether the selection for aggressiveness affects neurotransmitter levels in the avian central nervous system. We sought to identify the source and origin of this trait. We collected the brain samp...

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Autores principales: Komiyama, Tomoyoshi, Yoshikawa, Masanobu, Yokoyama, Keiko, Kobayashi, Hiroyuki
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7181795/
https://www.ncbi.nlm.nih.gov/pubmed/32332854
http://dx.doi.org/10.1038/s41598-020-63961-1
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author Komiyama, Tomoyoshi
Yoshikawa, Masanobu
Yokoyama, Keiko
Kobayashi, Hiroyuki
author_facet Komiyama, Tomoyoshi
Yoshikawa, Masanobu
Yokoyama, Keiko
Kobayashi, Hiroyuki
author_sort Komiyama, Tomoyoshi
collection PubMed
description Although the fighting behaviour in gamecocks has evolved because of artificial selection, it is unknown whether the selection for aggressiveness affects neurotransmitter levels in the avian central nervous system. We sought to identify the source and origin of this trait. We collected the brain samples from 6 female Shamo gamecocks and 5 Shaver Brown chickens (control; bred for egg production). The midbrain levels of norepinephrine (NE) were significantly higher in Shamo gamecocks (P = 0.0087) than in the controls. Moreover, alleles encoding adrenergic receptors differed between the breeds in terms of response to NE. Gene mutations specific to Shamo and potentially associated with fighting behaviour were in sites T440N of ADRα1D; V296I of ADRα2A; and T44I, Q232R, and T277M of ADRβ2. The evolutionary analysis indicated that the ADRβ2 (T44I and Q232R) mutations were heritable in all Galliformes, whereas the T440N mutation of ADRα1D and V296I mutations of ADRα2A were unique to Shamo and originated by artificial selection. A high NE level may confer a selective advantage by enabling gamecocks to be aggressive and pain tolerant. Therefore, the strong fighting behaviour of Shamo has resulted from a combination of naturally inherited and mutant genes derived by artificial selection.
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spelling pubmed-71817952020-04-29 Analysis of the source of aggressiveness in gamecocks Komiyama, Tomoyoshi Yoshikawa, Masanobu Yokoyama, Keiko Kobayashi, Hiroyuki Sci Rep Article Although the fighting behaviour in gamecocks has evolved because of artificial selection, it is unknown whether the selection for aggressiveness affects neurotransmitter levels in the avian central nervous system. We sought to identify the source and origin of this trait. We collected the brain samples from 6 female Shamo gamecocks and 5 Shaver Brown chickens (control; bred for egg production). The midbrain levels of norepinephrine (NE) were significantly higher in Shamo gamecocks (P = 0.0087) than in the controls. Moreover, alleles encoding adrenergic receptors differed between the breeds in terms of response to NE. Gene mutations specific to Shamo and potentially associated with fighting behaviour were in sites T440N of ADRα1D; V296I of ADRα2A; and T44I, Q232R, and T277M of ADRβ2. The evolutionary analysis indicated that the ADRβ2 (T44I and Q232R) mutations were heritable in all Galliformes, whereas the T440N mutation of ADRα1D and V296I mutations of ADRα2A were unique to Shamo and originated by artificial selection. A high NE level may confer a selective advantage by enabling gamecocks to be aggressive and pain tolerant. Therefore, the strong fighting behaviour of Shamo has resulted from a combination of naturally inherited and mutant genes derived by artificial selection. Nature Publishing Group UK 2020-04-24 /pmc/articles/PMC7181795/ /pubmed/32332854 http://dx.doi.org/10.1038/s41598-020-63961-1 Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as 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 images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Komiyama, Tomoyoshi
Yoshikawa, Masanobu
Yokoyama, Keiko
Kobayashi, Hiroyuki
Analysis of the source of aggressiveness in gamecocks
title Analysis of the source of aggressiveness in gamecocks
title_full Analysis of the source of aggressiveness in gamecocks
title_fullStr Analysis of the source of aggressiveness in gamecocks
title_full_unstemmed Analysis of the source of aggressiveness in gamecocks
title_short Analysis of the source of aggressiveness in gamecocks
title_sort analysis of the source of aggressiveness in gamecocks
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7181795/
https://www.ncbi.nlm.nih.gov/pubmed/32332854
http://dx.doi.org/10.1038/s41598-020-63961-1
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