Molecular phylogenetic evidence for a reversible morphogenetic switch controlling the gross morphology of two common genera of green seaweeds, Ulva and Enteromorpha
Authors: Tan, I.H., Blomster, J., Hansen, G., Leskinen, E., Maggs, C.A., Mann, D.G., Sluiman, H.J. and Stanhope, M.J.
Journal: Molecular Biology and Evolution
Volume: 16
Issue: 8
Pages: 1011-1018
ISSN: 0737-4038
DOI: 10.1093/oxfordjournals.molbev.a026190
Abstract:Ulva and Enteromorpha are two of the most common, ubiquitous, and environmentally important genera of green seaweeds. They are widely regarded as easily distinguishable because of their dramatically different morphologies: Ulva species are flat, lettucelike blades two cell layers thick, and Enteromorpha species form hollow liquid- or gas-filled tubes one cell thick, which may also be highly branched. We present molecular phylogenetic analyses of nuclear ribosomal RNA ITS sequences from 39 samples representing 21 purported species within these two genera. The results clearly indicate that the two genera are not respectively monophyletic and that the characteristic Ulva and Enteromorpha morphologies have arisen independently several times throughout the evolutionary diversification of the group. The analyses demonstrate that this radical change in gross morphology can also happen within clades exhibiting sequence divergence typical of conspecific assemblages of this group. We suggest that this morphological flexibility is the result of some form of developmental switch that results in either blades or tubes, but that this putative switch must be activated relatively infrequently, since there is evidence that some lineages have retained their form for significant periods. This discovery suggests a possible new model system for study of the molecular mechanisms involved in the interplay between environmental stimuli and plant development.
Source: Scopus
Molecular phylogenetic evidence for a reversible morphogenetic switch controlling the gross morphology of two common genera of green seaweeds, Ulva and Enteromorpha.
Authors: Tan, I.H., Blomster, J., Hansen, G., Leskinen, E., Maggs, C.A., Mann, D.G., Sluiman, H.J. and Stanhope, M.J.
Journal: Mol Biol Evol
Volume: 16
Issue: 8
Pages: 1011-1018
ISSN: 0737-4038
DOI: 10.1093/oxfordjournals.molbev.a026190
Abstract:Ulva and Enteromorpha are two of the most common, ubiquitous, and environmentally important genera of green seaweeds. They are widely regarded as easily distinguishable because of their dramatically different morphologies: Ulva species are flat, lettucelike blades two cell layers thick, and Enteromorpha species form hollow liquid- or gas-filled tubes one cell thick, which may also be highly branched. We present molecular phylogenetic analyses of nuclear ribosomal RNA ITS sequences from 39 samples representing 21 purported species within these two genera. The results clearly indicate that the two genera are not respectively monophyletic and that the characteristic Ulva and Enteromorpha morphologies have arisen independently several times throughout the evolutionary diversification of the group. The analyses demonstrate that this radical change in gross morphology can also happen within clades exhibiting sequence divergence typical of conspecific assemblages of this group. We suggest that this morphological flexibility is the result of some form of developmental switch that results in either blades or tubes, but that this putative switch must be activated relatively infrequently, since there is evidence that some lineages have retained their form for significant periods. This discovery suggests a possible new model system for study of the molecular mechanisms involved in the interplay between environmental stimuli and plant development.
Source: PubMed
Molecular phylogenetic evidence for a reversible morphogenetic switch controlling the gross morphology of two common genera of green seaweeds, <i>Ulva</i> and <i>Enteromorpha</i>
Authors: Tan, I.H., Blomster, J., Hansen, G., Leskinen, E., Maggs, C.A., Mann, D.G., Sluimam, H.J. and Stanhope, M.J.
Journal: MOLECULAR BIOLOGY AND EVOLUTION
Volume: 16
Issue: 8
Pages: 1011-1018
ISSN: 0737-4038
DOI: 10.1093/oxfordjournals.molbev.a026190
Source: Web of Science (Lite)
Molecular phylogenetic evidence for a reversible morphogenetic switch controlling the gross morphology of two common genera of green seaweeds, Ulva and Enteromorpha.
Authors: Tan, I.H., Blomster, J., Hansen, G., Leskinen, E., Maggs, C.A., Mann, D.G., Sluiman, H.J. and Stanhope, M.J.
Journal: Molecular biology and evolution
Volume: 16
Issue: 8
Pages: 1011-1018
eISSN: 1537-1719
ISSN: 0737-4038
DOI: 10.1093/oxfordjournals.molbev.a026190
Abstract:Ulva and Enteromorpha are two of the most common, ubiquitous, and environmentally important genera of green seaweeds. They are widely regarded as easily distinguishable because of their dramatically different morphologies: Ulva species are flat, lettucelike blades two cell layers thick, and Enteromorpha species form hollow liquid- or gas-filled tubes one cell thick, which may also be highly branched. We present molecular phylogenetic analyses of nuclear ribosomal RNA ITS sequences from 39 samples representing 21 purported species within these two genera. The results clearly indicate that the two genera are not respectively monophyletic and that the characteristic Ulva and Enteromorpha morphologies have arisen independently several times throughout the evolutionary diversification of the group. The analyses demonstrate that this radical change in gross morphology can also happen within clades exhibiting sequence divergence typical of conspecific assemblages of this group. We suggest that this morphological flexibility is the result of some form of developmental switch that results in either blades or tubes, but that this putative switch must be activated relatively infrequently, since there is evidence that some lineages have retained their form for significant periods. This discovery suggests a possible new model system for study of the molecular mechanisms involved in the interplay between environmental stimuli and plant development.
Source: Europe PubMed Central