The Rhodoexplorer website aims to provide comprehensive access to published complete red algal genome sequences. This website was launched as part of the Gracilariaceae genome project.

The Gracilariaceae genome project is sequencing the genome of four species from this family: Gracilaria caudata, Gracilaria chilensis, Gracilaria vermiculophylla and Gracilaria gracilis. These species are of interest for a number of aspects, including their life cycles and reproductive biology, as domesticated and cultivated species, as invasive species and for their characteristic cell walls. The Gracilariaceae genome project involves partners at the Roscoff Biological Station (France), the University of Sao Paulo (Brazil), Universidad Austral de Chile (Chile), the Virginia Institute of Marine Science Eastern Shore Laboratory (USA), the College of Charleston (USA), the Max Planck Institute in Tübingen (Germany), GEOMAR, Kiel (Germany) and the University of Oldenburg (Germany). The project is funded by the ANR infrastructures project Idealg and by the CNRS International Research Network program (DABMA project).

Funding

The project is funded by the ANR infrastructures project Idealg , by the CNRS International Research Network program (DABMA project). This project was funded by the College of Arts and Sciences at The University of Alabama at Birmingham start-up funds to S.A. Krueger-Hadfield.

Co-coordinators

• Agnieszka Lipinska (Max Planck Institute for Biology, Tuebingen, Germany)
• Stacy Krueger-Hadfield (Virginia Institute of Marine Science Eastern Shore Laboratory, USA)
• Simon Dittami (Station Biologique de Roscoff, France)

Contributors

• Lígia Ayres-Ostrock (Universidade de São Paulo, Brazil)
• Jessica Beltran (Pontificia Universidad Católica de Chile)
• Guido Bonthond (University of Oldenburg, Germany)
• Loraine Brillet-Guéguen (Station Biologique de Roscoff, France)
• Mariana Cabral de Oliveira (Universidade de São Paulo, Brazil)
• Susana Coelho (Max Planck Institute for Biology, Tuebingen, Germany)
• Erwan Corre (Station Biologique de Roscoff, France)
• Guillaume Cossard (Station Biologique de Roscoff, France)
• Christophe Destombe (Station Biologique de Roscoff, France)
• Sylvain Faugeron (Pontificia Universidad Católica de Chile)
• Elizabeth Ficko-Blean (Station Biologique de Roscoff, France)
• Olivier Godfroy (Station Biologique de Roscoff, France)
• Marie-Laure Guillemin (Universidad Austral de Chile)
• Emma Lavaut (Station Biologique de Roscoff, France)
• Arthur Le Bars (Station Biologique de Roscoff, France)
• Fabiana Marchi (Universidade de São Paulo, Brazil)
• Stéphane Mauger (Station Biologique de Roscoff, France)
• Gurvan Michel (Station Biologique de Roscoff, France)
• Estela Plastino (Maria Universidade de São Paulo, Brazil)
• Philippe Potin (Station Biologique de Roscoff, France)
• Delphine Scornet (Station Biologique de Roscoff, France)
• Erik Sotka (College of Charleston, USA)
• Myriam Valero (Station Biologique de Roscoff, France)
• Florian Weinberger (GEOMAR Helmholtz-Zentrum für Ozeanforrschung, Kiel, Germany)

Mazzaella laminarioides is a marine red alga common along Chilean rocky shores, comprising three cryptic genetic lineages (North, Center, South) that differ in their degree of divergence, the North lineage being far more distantly related to the other two than Center and South are from each other, and that meet in parapatry at distinct contact zones. This project uses these lineages as novel biological models to investigate how barriers to gene flow accumulate during speciation in a group largely overlooked in speciation genomics: red algae characterized by haploid-diploid life cycles and UV sex chromosomes. Using whole-genome assemblies and whole-genome genotyping of both haploid and diploid individuals, we aim to reconstruct the evolutionary history of the three lineages and characterize the genomic architecture of reproductive isolation. Comparing lineage pairs at different stages of divergence and in distinct geographic settings offers an integrated view of how genome architecture and geographic context jointly shape the speciation process in marine red algae.

Using 12 whole-genome sequencing datasets, this study reconstructed the evolutionary history of the three lineages through phylogenomic analyses and demographic modelling, supporting a scenario of ancient migration followed by prolonged isolation and population bottlenecks. Lineage-specific analyses of coding-sequence evolution further revealed divergent selective pressures on energy-acquisition genes in the South lineage, suggesting that environmental gradients along the Chilean coast have also contributed to lineage differentiation. The six high-quality genomes (PacBio + Illumina) generated for this publication are deposited in RhodoExplorer.

Publication

Torres et al. Genome-wide insights into the evolutionary and demographic history of the red alga Mazzaella laminarioides: speciation with ancient migration along the southeastPacific coast. Submitted

Funding

This project was supported by the Agencia Nacional de Investigación y Desarrollo (ANID) FONDECYT #1221477 "Diverging lineages of Mazzaella laminarioides as new biological models to study speciation and barriers to gene flow in haploid-diploid organisms"