Diversification of the light-harvesting complex gene family via intra- and intergenic duplications in the coral symbiotic alga Symbiodinium.

The light-harvesting complex (LHC) is an essential component in light energy capture and transduction to facilitate downstream photosynthetic reactions in plant and algal chloroplasts. The unicellular dinoflagellate alga Symbiodinium is an endosymbiont of cnidarian animals, including corals and sea...

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Main Authors: Shinichiro Maruyama, Eiichi Shoguchi, Nori Satoh, Jun Minagawa
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4351107?pdf=render
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author Shinichiro Maruyama
Eiichi Shoguchi
Nori Satoh
Jun Minagawa
author_facet Shinichiro Maruyama
Eiichi Shoguchi
Nori Satoh
Jun Minagawa
author_sort Shinichiro Maruyama
collection DOAJ
description The light-harvesting complex (LHC) is an essential component in light energy capture and transduction to facilitate downstream photosynthetic reactions in plant and algal chloroplasts. The unicellular dinoflagellate alga Symbiodinium is an endosymbiont of cnidarian animals, including corals and sea anemones, and provides carbohydrates generated through photosynthesis to host animals. Although Symbiodinium possesses a unique LHC gene family, called chlorophyll a-chlorophyll c2-peridinin protein complex (acpPC), its genome-level diversity and evolutionary trajectories have not been investigated. Here, we describe a phylogenetic analysis revealing that many of the LHCs are encoded by highly duplicated genes with multi-subunit polyprotein structures in the nuclear genome of Symbiodinium minutum. This analysis provides an extended list of the LHC gene family in a single organism, including 80 loci encoding polyproteins composed of 145 LHC subunits recovered in the phylogenetic tree. In S. minutum, 5 phylogenetic groups of the Lhcf-type gene family, which is exclusively conserved in algae harboring secondary plastids of red algal origin, were identified. Moreover, 5 groups of the Lhcr-type gene family, of which members are known to be associated with PSI in red algal plastids and secondary plastids of red algal origin, were identified. Notably, members classified within a phylogenetic group of the Lhcf-type (group F1) are highly duplicated, which may explain the presence of an unusually large number of LHC genes in this species. Some gene units were homologous to other units within single loci of the polyprotein genes, whereas intergenic homologies between separate loci were conspicuous in other cases, implying that gene unit 'shuffling' by gene conversion and/or genome rearrangement might have been a driving force for diversification. These results suggest that vigorous intra- and intergenic gene duplication events have resulted in the genomic framework of photosynthesis in coral symbiont dinoflagellate algae.
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spelling doaj.art-9b7f6cbf9bc04fefb439303c3279412b2022-12-21T23:52:07ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-01103e011940610.1371/journal.pone.0119406Diversification of the light-harvesting complex gene family via intra- and intergenic duplications in the coral symbiotic alga Symbiodinium.Shinichiro MaruyamaEiichi ShoguchiNori SatohJun MinagawaThe light-harvesting complex (LHC) is an essential component in light energy capture and transduction to facilitate downstream photosynthetic reactions in plant and algal chloroplasts. The unicellular dinoflagellate alga Symbiodinium is an endosymbiont of cnidarian animals, including corals and sea anemones, and provides carbohydrates generated through photosynthesis to host animals. Although Symbiodinium possesses a unique LHC gene family, called chlorophyll a-chlorophyll c2-peridinin protein complex (acpPC), its genome-level diversity and evolutionary trajectories have not been investigated. Here, we describe a phylogenetic analysis revealing that many of the LHCs are encoded by highly duplicated genes with multi-subunit polyprotein structures in the nuclear genome of Symbiodinium minutum. This analysis provides an extended list of the LHC gene family in a single organism, including 80 loci encoding polyproteins composed of 145 LHC subunits recovered in the phylogenetic tree. In S. minutum, 5 phylogenetic groups of the Lhcf-type gene family, which is exclusively conserved in algae harboring secondary plastids of red algal origin, were identified. Moreover, 5 groups of the Lhcr-type gene family, of which members are known to be associated with PSI in red algal plastids and secondary plastids of red algal origin, were identified. Notably, members classified within a phylogenetic group of the Lhcf-type (group F1) are highly duplicated, which may explain the presence of an unusually large number of LHC genes in this species. Some gene units were homologous to other units within single loci of the polyprotein genes, whereas intergenic homologies between separate loci were conspicuous in other cases, implying that gene unit 'shuffling' by gene conversion and/or genome rearrangement might have been a driving force for diversification. These results suggest that vigorous intra- and intergenic gene duplication events have resulted in the genomic framework of photosynthesis in coral symbiont dinoflagellate algae.http://europepmc.org/articles/PMC4351107?pdf=render
spellingShingle Shinichiro Maruyama
Eiichi Shoguchi
Nori Satoh
Jun Minagawa
Diversification of the light-harvesting complex gene family via intra- and intergenic duplications in the coral symbiotic alga Symbiodinium.
PLoS ONE
title Diversification of the light-harvesting complex gene family via intra- and intergenic duplications in the coral symbiotic alga Symbiodinium.
title_full Diversification of the light-harvesting complex gene family via intra- and intergenic duplications in the coral symbiotic alga Symbiodinium.
title_fullStr Diversification of the light-harvesting complex gene family via intra- and intergenic duplications in the coral symbiotic alga Symbiodinium.
title_full_unstemmed Diversification of the light-harvesting complex gene family via intra- and intergenic duplications in the coral symbiotic alga Symbiodinium.
title_short Diversification of the light-harvesting complex gene family via intra- and intergenic duplications in the coral symbiotic alga Symbiodinium.
title_sort diversification of the light harvesting complex gene family via intra and intergenic duplications in the coral symbiotic alga symbiodinium
url http://europepmc.org/articles/PMC4351107?pdf=render
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