6 Genomics of Marine Algae
203
P. umbilicalis (genomes of Porphyra spp. tend to be around 400 Mbp, Kapraun
2005) and of being more representative of the “typical” red algae (the majority of
red algae are florideophytes). Both the C. crispus and the P. umbilicalis genomes
will be of interest for applied research, C. crispus for understanding carrageenan
biosynthesis and P. umbilicalis because of the importance of Porphyra spp. (nori)
in the multibillion dollar nori industry. It is also important to note that the common
ancestor of C. crispus and P. umbilicalis is though to date back to about 1,400 Mya,
so these two species represent very different evolutionary groups (Yoon et al. 2004).
6.4.6.3 Green Macroalgae
Genomic approaches have not been applied to the same extent to green marine
macroalgae as they have for the reds and browns. This is probably because of the less
obvious potential for industrial applications. However, green macroalgae such as
Ulva are important for their roles in fouling and because of their tendency to bloom
under high nutrient conditions, for example when pollution by fertilisers is combined with the warm temperatures and high light fluxes during the summer months
in temperate regions. Among the green marine macroalgae, Ulva has been studied most extensively and a collection of ESTs has been established (Bryhni 1974,
Fjeld and Løvle 1976, Reddy et al. 1992). At present, however, there are no plans to
sequence the genome of a member of this group.
Sea-grasses are angiosperms and, therefore, are not defined as algae. It is important to mention these organisms here though because, like the macroalgae, they are
ecologically import photosynthetic organisms in many coastal regions. Sea-grasses
can form extensive “meadows” on sandy or muddy shorelines, providing a habitat
for many other organisms. These important ecosystems are threatened by human
activity in many parts of the world. A genome sequencing project has been initiated
for one species of sea-grass, the eelgrass Zostera marina (Table 6.1).
6.5 Future Research in Algal Genomics
Genomic approaches are currently being used to address a very broad range of
questions related to algal biology. These include questions addressing fundamental
aspects of the evolution of the eukaryotes, questions concerning the key roles played
by algae in various open-ocean and coastal ecosystems and in-depth studies of
specific aspects of algal biology, the latter often with novel biotechnological applications. Future research will extend our knowledge in all of these areas. Sequence
data is still very fragmentary and many of the major eukaryotic groups are still
very poorly explored at the molecular level. Future work will fill in many of these
gaps, adding robustness to the eukaryote phylogeny. However, it is likely that major
eukaryotic groups still remain to be discovered (Not et al. 2007) and, consequently,
that currently recognised supergroups of the eukaryotic tree may need to be reorganised. New information is also expected about the various endosymbiotic events
that played such an important role during evolution.
203
P. umbilicalis (genomes of Porphyra spp. tend to be around 400 Mbp, Kapraun
2005) and of being more representative of the “typical” red algae (the majority of
red algae are florideophytes). Both the C. crispus and the P. umbilicalis genomes
will be of interest for applied research, C. crispus for understanding carrageenan
biosynthesis and P. umbilicalis because of the importance of Porphyra spp. (nori)
in the multibillion dollar nori industry. It is also important to note that the common
ancestor of C. crispus and P. umbilicalis is though to date back to about 1,400 Mya,
so these two species represent very different evolutionary groups (Yoon et al. 2004).
6.4.6.3 Green Macroalgae
Genomic approaches have not been applied to the same extent to green marine
macroalgae as they have for the reds and browns. This is probably because of the less
obvious potential for industrial applications. However, green macroalgae such as
Ulva are important for their roles in fouling and because of their tendency to bloom
under high nutrient conditions, for example when pollution by fertilisers is combined with the warm temperatures and high light fluxes during the summer months
in temperate regions. Among the green marine macroalgae, Ulva has been studied most extensively and a collection of ESTs has been established (Bryhni 1974,
Fjeld and Løvle 1976, Reddy et al. 1992). At present, however, there are no plans to
sequence the genome of a member of this group.
Sea-grasses are angiosperms and, therefore, are not defined as algae. It is important to mention these organisms here though because, like the macroalgae, they are
ecologically import photosynthetic organisms in many coastal regions. Sea-grasses
can form extensive “meadows” on sandy or muddy shorelines, providing a habitat
for many other organisms. These important ecosystems are threatened by human
activity in many parts of the world. A genome sequencing project has been initiated
for one species of sea-grass, the eelgrass Zostera marina (Table 6.1).
6.5 Future Research in Algal Genomics
Genomic approaches are currently being used to address a very broad range of
questions related to algal biology. These include questions addressing fundamental
aspects of the evolution of the eukaryotes, questions concerning the key roles played
by algae in various open-ocean and coastal ecosystems and in-depth studies of
specific aspects of algal biology, the latter often with novel biotechnological applications. Future research will extend our knowledge in all of these areas. Sequence
data is still very fragmentary and many of the major eukaryotic groups are still
very poorly explored at the molecular level. Future work will fill in many of these
gaps, adding robustness to the eukaryote phylogeny. However, it is likely that major
eukaryotic groups still remain to be discovered (Not et al. 2007) and, consequently,
that currently recognised supergroups of the eukaryotic tree may need to be reorganised. New information is also expected about the various endosymbiotic events
that played such an important role during evolution.