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Updated: May 21, 2026
04:20
Extraction of Diatom DNA from Water Samples and Tissues
Published on: November 10, 2023
Reevaluating the green contribution to diatom genomes
Philippe Deschamps1, David Moreira
1Unité d'Ecologie, Systématique et Evolution, UMR CNRS 8079, Univ. Paris-Sud, Orsay, France. philippe.deschamps@u-psud.fr
Genome Biology and Evolution
|June 12, 2012
Summary
The origin of diatom plastids is debated. This study shows that most genes supporting a green algal origin are due to taxonomic bias, with red algal endosymbiosis being the primary source of gene transfers.
Area of Science:
- * Algal endosymbiosis
- * Molecular evolution
- * Phylogenomics
Background:
- * Diatom plastids are proposed to originate from red algal secondary endosymbiosis.
- * Recent studies suggest a cryptic green algal endosymbiosis based on nuclear gene phylogenies.
- * Endosymbiotic gene transfer (EGT) is a key process in organelle evolution.
Purpose of the Study:
- * To re-evaluate the origin of diatom plastids and the role of endosymbiotic gene transfer.
- * To investigate the contribution of red versus green algal endosymbiosis to the diatom nuclear genome.
- * To address taxonomic sampling biases in previous phylogenomic analyses.
Main Methods:
- * Phylogenomic analysis of diatom nuclear genes.
- * Expanded genomic data from red algae were incorporated.
- * Re-evaluation of gene phylogenies for evidence of endosymbiotic gene transfer.
Main Results:
- * Previous studies exhibited taxonomic sampling bias, affecting gene tree interpretations.
- * A majority of gene phylogenies were poorly resolved or did not support green algal EGT.
- * Genes with complete descent from cyanobacteria to diatoms primarily involved red algal EGT.
Conclusions:
- * The evidence for a cryptic green algal secondary endosymbiosis in diatoms is weak.
- * Red algal endosymbiosis is the predominant pathway for gene transfer to the diatom nucleus.
- * The origin of diatom plastids is robustly supported by red algal endosymbiosis.
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