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Preparation of Prokaryotic and Eukaryotic Organisms Using Chemical Drying for Morphological Analysis in Scanning Electron Microscopy (SEM)
Published on: January 7, 2019
Evolution of distorted pellicle patterns in rigid photosynthetic euglenids (phacus dujardin)
Heather J Esson1, Brian S Leander
1Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, Canada V6T 1Z4. heather.esson@univie.ac.at
The Journal of Eukaryotic Microbiology
|November 3, 2009
Summary
The study reveals that most Phacus euglenids exhibit unique, bilaterally symmetrical pellicle strip patterns, differing from their relatives. These patterns evolved with cell flattening and rigidity, likely adaptations for a planktonic lifestyle.
Area of Science:
- * Evolutionary biology
- * Protistology
- * Microscopy and phylogenetics
Background:
- * The euglenid genus Phacus is characterized by a rigid pellicle and flattened, leaf-shaped cells.
- * Previous studies have not fully elucidated the evolutionary history of Phacus pellicle morphology.
Purpose of the Study:
- * To investigate the evolutionary patterns of pellicle strip arrangements in the genus Phacus.
- * To understand the developmental and adaptive significance of these morphological traits.
Main Methods:
- * Scanning electron microscopy (SEM) was used to examine pellicle strip patterns in ten Phacus species and one related genus.
- * Comparative morphology was integrated with molecular phylogenetic analyses (nuclear rDNA sequences).
Main Results:
- * The earliest diverging Phacus species (P. warszewiczii) displays a whorled reduction pattern.
- * Most Phacus species exhibit clustered posterior strip reduction, a deviation from radial symmetry.
- * This clustered pattern is a derived trait, evolving after Phacus diverged from other euglenids.
Conclusions:
- * Clustered pellicle strip patterns in Phacus are linked to developmental processes governing strip length.
- * These patterns are associated with the evolution of cell flattening and rigidity, potentially adaptive for planktonic life.
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