Diversity and evolution of pigment types in marine $Synechococcus$ cyanobacteria - Archive ouverte HAL Access content directly
Journal Articles Genome Biology and Evolution Year : 2022

Diversity and evolution of pigment types in marine $Synechococcus$ cyanobacteria

Morgane Ratin
Patrick Wincker

Abstract

Synechococcus cyanobacteria are ubiquitous and abundant in the marine environment and contribute to an estimated 16% of the ocean net primary productivity. Their light-harvesting complexes, called phycobilisomes (PBS), are composed of a conserved allophycocyanin core, from which radiates six to eight rods with variable phycobiliprotein and chromophore content. This variability allows Synechococcus cells to optimally exploit the wide variety of spectral niches existing in marine ecosystems. Seven distinct pigment types or subtypes have been identified so far in this taxon based on the phycobiliprotein composition and/or the proportion of the different chromophores in PBS rods. Most genes involved in their biosynthesis and regulation are located in a dedicated genomic region called the PBS rod region. Here, we examine the variability of gene content and organization of this genomic region in a large set of sequenced isolates and natural populations of Synechococcus representative of all known pigment types. All regions start with a tRNA-PheGAA and some possess mobile elements for DNA integration and site-specific recombination, suggesting that their genomic variability relies in part on a “tycheposon”-like mechanism. Comparison of the phylogenies obtained for PBS and core genes revealed that the evolutionary history of PBS rod genes differs from the core genome and is characterized by the co-existence of different alleles and frequent allelic exchange. We propose a scenario for the evolution of the different pigment types and highlight the importance of incomplete lineage sorting in maintaining a wide diversity of pigment types in different Synechococcus lineages despite multiple speciation events.
Fichier principal
Vignette du fichier
Grebert et al_GBE_2022_preprint.pdf (9.94 Mo) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

hal-03641745 , version 1 (07-10-2022)

Identifiers

Cite

Théophile Grébert, Laurence Garczarek, Vincent Daubin, Florian Humily, Dominique Marie, et al.. Diversity and evolution of pigment types in marine $Synechococcus$ cyanobacteria. Genome Biology and Evolution, 2022, 14 (4), pp.evac035. ⟨10.1093/gbe/evac035⟩. ⟨hal-03641745⟩
114 View
7 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More