Reference number : GC-2017-Q1-02036, amendment number : , agreement type : G, recipient legal name : Lemieux, Claude (Université Laval), recipient country : CA, recipient province : nan, recipient city : Quebec|Québec, recipient postal code : nan, program name english : Discovery Grants Program - Individual, program name french : Programme de subventions à la découverte - individuelles, program purpose english : The green algae represent one of the most successful groups of photosynthetic eukaryotes, but surprisingly little is known about their evolutionary history. About 450-500 million years ago (mya), a subset of freshwater green algae gave rise to the first land plants. Together with the land plants, green algae constitute the so-called green lineage or Viridiplantae. The Viridiplantae comprises 2 divisions: the Chlorophyta, containing the majority of the green algae, and the Streptophyta, containing all land plants and their closest green algal relatives, known as charophytes. 
 Knowledge about the positions of the diverse green algal groups in the tree of life is essential for identifying the innovations underlying their remarkable adaptations to different environments. To decipher the phylogenetic relationships among major green algal lineages, my research team has been analyzing the genomes found in the chloroplasts and mitochondria. As a matter of fact, we have pioneered this comparative genomic approach for the study of green algae. We have shown that the chloroplast (cp) genome is a useful source of data for phylogenetic inference and that, contrary to what has been observed for land plants, it underwent tremendous changes during green algal diversification. The rRNA operon-encoding inverted repeat (IR) &ndash; a hallmark of the cp genome &ndash; experienced multiple waves of expansion/contraction and numerous losses in green algae; however, despite the suggested functional importance of the IR, the mechanism(s) underlying IR loss remain unclear. 
 This proposal addresses fundamental issues on the evolution of chlorophytes and their genomes. To achieve 3 of the 4 delineated objectives, cp genomes of taxa from 3 distinct evolutionary nodes will be investigated. One of these objectives is to better understand the roles and properties of the IR along with the mechanisms of IR loss; the proposed analyses are based on our recent findings that the 2 IR copies diverged in sequence in 3 lineages of the Ulvophyceae and that this unprecedented discovery is compatible with a novel model of IR loss we proposed for the Ulotrichales. In another innovative line of inquiry, we plan to study the nuclear genome architectures of 2 prasinophytes from the lineage presumed to be sister to all core chlorophytes (the so-called clade VII); the goals are to gain insights into the biology of these algae and into the genomic changes that occurred during the transition from prasinophytes to core chlorophytes about 900 mya. These large-scale genomic studies are also likely to advance knowledge about algal adaptation to high salinity. 
 The proposed research will provide high-quality training opportunities for graduate and undergraduate students in the areas of genomics and bioinformatics. Because these fields of science have multiple application domains, the proposal is expected to contribute to the economic and societal health of Canada., program purpose french : The green algae represent one of the most successful groups of photosynthetic eukaryotes, but surprisingly little is known about their evolutionary history. About 450-500 million years ago (mya), a subset of freshwater green algae gave rise to the first land plants. Together with the land plants, green algae constitute the so-called green lineage or Viridiplantae. The Viridiplantae comprises 2 divisions: the Chlorophyta, containing the majority of the green algae, and the Streptophyta, containing all land plants and their closest green algal relatives, known as charophytes. 
 Knowledge about the positions of the diverse green algal groups in the tree of life is essential for identifying the innovations underlying their remarkable adaptations to different environments. To decipher the phylogenetic relationships among major green algal lineages, my research team has been analyzing the genomes found in the chloroplasts and mitochondria. As a matter of fact, we have pioneered this comparative genomic approach for the study of green algae. We have shown that the chloroplast (cp) genome is a useful source of data for phylogenetic inference and that, contrary to what has been observed for land plants, it underwent tremendous changes during green algal diversification. The rRNA operon-encoding inverted repeat (IR) &ndash; a hallmark of the cp genome &ndash; experienced multiple waves of expansion/contraction and numerous losses in green algae; however, despite the suggested functional importance of the IR, the mechanism(s) underlying IR loss remain unclear. 
 This proposal addresses fundamental issues on the evolution of chlorophytes and their genomes. To achieve 3 of the 4 delineated objectives, cp genomes of taxa from 3 distinct evolutionary nodes will be investigated. One of these objectives is to better understand the roles and properties of the IR along with the mechanisms of IR loss; the proposed analyses are based on our recent findings that the 2 IR copies diverged in sequence in 3 lineages of the Ulvophyceae and that this unprecedented discovery is compatible with a novel model of IR loss we proposed for the Ulotrichales. In another innovative line of inquiry, we plan to study the nuclear genome architectures of 2 prasinophytes from the lineage presumed to be sister to all core chlorophytes (the so-called clade VII); the goals are to gain insights into the biology of these algae and into the genomic changes that occurred during the transition from prasinophytes to core chlorophytes about 900 mya. These large-scale genomic studies are also likely to advance knowledge about algal adaptation to high salinity. 
 The proposed research will provide high-quality training opportunities for graduate and undergraduate students in the areas of genomics and bioinformatics. Because these fields of science have multiple application domains, the proposal is expected to contribute to the economic and societal health of Canada., agreement title english : Unraveling the evolutionary history of the green algae and their genomes, agreement title french : Unraveling the evolutionary history of the green algae and their genomes, agreement number : RGPIN, agreement value : 140000.0, agreement start date : 2017-05-10, agreement end date : nan, description english : nan, description french : nan, expected results english : nan, expected results french : nan, additional information english : Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023), additional information french : Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023), owner organization : nserc-crsng, owner organization title : Natural Sciences and Engineering Research Council of Canada | Conseil de recherches en sciences naturelles et en génie du Canada