Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system

Abstract Background Piscirickettsiosis or Salmonid Rickettsial Septicaemia (SRS) is a bacterial disease that has a major economic impact on the Chilean salmon farming industry. Despite the fact that Piscirickettsia salmonis has been recognized as a major fish pathogen for over 20 years, the molecula...

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Main Authors: Pulgar, Rodrigo, Hödar, Christian, Travisany, Dante, Zuñiga, Alejandro, Domínguez, Calixto, Maass, Alejandro, González, Mauricio, Cambiazo, Verónica
Format: Article in Journal/Newspaper
Language:English
Published: BioMed Central Ltd. 2015
Subjects:
Online Access:http://www.biomedcentral.com/1471-2164/16/495
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spelling ftbiomed:oai:biomedcentral.com:s12864-015-1716-9 2023-05-15T15:30:34+02:00 Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system Pulgar, Rodrigo Hödar, Christian Travisany, Dante Zuñiga, Alejandro Domínguez, Calixto Maass, Alejandro González, Mauricio Cambiazo, Verónica 2015-07-04 http://www.biomedcentral.com/1471-2164/16/495 en eng BioMed Central Ltd. http://www.biomedcentral.com/1471-2164/16/495 Copyright 2015 Pulgar et al. Atlantic salmon families Piscirickettsia salmonis Infection susceptibility Iron-deprivation Gene expression Research article 2015 ftbiomed 2015-07-04T23:59:57Z Abstract Background Piscirickettsiosis or Salmonid Rickettsial Septicaemia (SRS) is a bacterial disease that has a major economic impact on the Chilean salmon farming industry. Despite the fact that Piscirickettsia salmonis has been recognized as a major fish pathogen for over 20 years, the molecular strategies underlying the fish response to infection and the bacterial mechanisms of pathogenesis are poorly understood. We analysed and compared the head kidney transcriptional response of Atlantic salmon (Salmo salar) families with different levels of susceptibility to P. salmonis infection in order to reveal mechanisms that might confer infection resistance. Results We ranked forty full-sibling Atlantic salmon families according to accumulated mortality after a challenge with P. salmonis and selected the families with the lowest and highest cumulative mortalities for microarray gene expression analysis. A comparison of the response to P. salmonis infection between low and high susceptibility groups identified biological processes presumably involved in natural resistance to the pathogen. In particular, expression changes of genes linked to cellular iron depletion, as well as low iron content and bacterial load in the head kidney of fish from low susceptibility families, suggest that iron-deprivation is an innate immunity defence mechanism against P. salmonis . To complement these results, we predicted a set of iron acquisition genes from the P. salmonis genome. Identification of putative Fur boxes and expression of the genes under iron-depleted conditions revealed that most of these genes form part of the Fur regulon of P. salmonis. Conclusions This study revealed, for the first time, differences in the transcriptional response to P. salmonis infection among Atlantic salmon families with varied levels of susceptibility to the infection. These differences correlated with changes in the abundance of transcripts encoding proteins directly and indirectly involved in the immune response; changes that highlighted the role of nutritional immunity through iron deprivation in host defence mechanisms against P. salmonis . Additionally, we found that P. salmonis has several mechanisms for iron acquisition, suggesting that this bacterium can obtain iron from different sources, including ferric iron through capturing endogenous and exogenous siderophores and ferrous iron. Our results contribute . Article in Journal/Newspaper Atlantic salmon Salmo salar BioMed Central
institution Open Polar
collection BioMed Central
op_collection_id ftbiomed
language English
topic Atlantic salmon families
Piscirickettsia salmonis
Infection susceptibility
Iron-deprivation
Gene expression
spellingShingle Atlantic salmon families
Piscirickettsia salmonis
Infection susceptibility
Iron-deprivation
Gene expression
Pulgar, Rodrigo
Hödar, Christian
Travisany, Dante
Zuñiga, Alejandro
Domínguez, Calixto
Maass, Alejandro
González, Mauricio
Cambiazo, Verónica
Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system
topic_facet Atlantic salmon families
Piscirickettsia salmonis
Infection susceptibility
Iron-deprivation
Gene expression
description Abstract Background Piscirickettsiosis or Salmonid Rickettsial Septicaemia (SRS) is a bacterial disease that has a major economic impact on the Chilean salmon farming industry. Despite the fact that Piscirickettsia salmonis has been recognized as a major fish pathogen for over 20 years, the molecular strategies underlying the fish response to infection and the bacterial mechanisms of pathogenesis are poorly understood. We analysed and compared the head kidney transcriptional response of Atlantic salmon (Salmo salar) families with different levels of susceptibility to P. salmonis infection in order to reveal mechanisms that might confer infection resistance. Results We ranked forty full-sibling Atlantic salmon families according to accumulated mortality after a challenge with P. salmonis and selected the families with the lowest and highest cumulative mortalities for microarray gene expression analysis. A comparison of the response to P. salmonis infection between low and high susceptibility groups identified biological processes presumably involved in natural resistance to the pathogen. In particular, expression changes of genes linked to cellular iron depletion, as well as low iron content and bacterial load in the head kidney of fish from low susceptibility families, suggest that iron-deprivation is an innate immunity defence mechanism against P. salmonis . To complement these results, we predicted a set of iron acquisition genes from the P. salmonis genome. Identification of putative Fur boxes and expression of the genes under iron-depleted conditions revealed that most of these genes form part of the Fur regulon of P. salmonis. Conclusions This study revealed, for the first time, differences in the transcriptional response to P. salmonis infection among Atlantic salmon families with varied levels of susceptibility to the infection. These differences correlated with changes in the abundance of transcripts encoding proteins directly and indirectly involved in the immune response; changes that highlighted the role of nutritional immunity through iron deprivation in host defence mechanisms against P. salmonis . Additionally, we found that P. salmonis has several mechanisms for iron acquisition, suggesting that this bacterium can obtain iron from different sources, including ferric iron through capturing endogenous and exogenous siderophores and ferrous iron. Our results contribute .
format Article in Journal/Newspaper
author Pulgar, Rodrigo
Hödar, Christian
Travisany, Dante
Zuñiga, Alejandro
Domínguez, Calixto
Maass, Alejandro
González, Mauricio
Cambiazo, Verónica
author_facet Pulgar, Rodrigo
Hödar, Christian
Travisany, Dante
Zuñiga, Alejandro
Domínguez, Calixto
Maass, Alejandro
González, Mauricio
Cambiazo, Verónica
author_sort Pulgar, Rodrigo
title Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system
title_short Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system
title_full Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system
title_fullStr Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system
title_full_unstemmed Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system
title_sort transcriptional response of atlantic salmon families to piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system
publisher BioMed Central Ltd.
publishDate 2015
url http://www.biomedcentral.com/1471-2164/16/495
genre Atlantic salmon
Salmo salar
genre_facet Atlantic salmon
Salmo salar
op_relation http://www.biomedcentral.com/1471-2164/16/495
op_rights Copyright 2015 Pulgar et al.
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