- Mesotaenium is
a unicellular placoderm desmid with short, straight, cylindrical
cells. Each cell has a single axial, plate-like
chloroplast with one or several pyrenoids.
The cells are solitary or aggregated within common mucilage to
form irregular colonies.
-
- Placoderm desmids are unicells or pseudofilaments
whose cell walls have pores and are made up of two parts of different
ages separated by an isthmus. Saccoderm desmids instead have
a homogeneous cell wall that lacks pores.
-
- Like Mougeotia, Mesotaenium's
chloroplasts rotate much like a mechanized solar panel to maximize
usable light. Sensory pigments detect the wavelength and position
of the light. A transducer translates this information into a
chemical code that signals a mechanical effector to move the
chloroplast. Phytochrome, the primary signal perceptor in Mesotaenium,
has been isolated and researched and found to be similar to corresponding
plant pigments.
-
- Molecular sequence analyses have shown that
morphology does not reflect the evolutionary patterns
- of the zygnematalean algae. Rather than all
of the filaments or all of the unicells sharing a common evolutionary
origin, closely related genera instead have similar chloroplast
structure.
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