Scientists sequence tropical marine organism genome
German and American researchers have successfully sequenced the genome of Lyngbya majuscula (L. majuscula), a tropical marine organism able to generate substances that can be used in the treatment of human disorders including neurodegenerative diseases and cancer. The study is presented in the journal Proceedings of the National Academy of Sciences (PNAS). Filamentous cyanobacteria of the genus Lyngbya play a crucial role in the global carbon cycle; coral reef ecosystems benefit from their activity, as they can form dominant covers and affect the health of other co-occurring organisms. It should be noted, however, that when these strains upset healthy coral reef growth, they cause a skin rash problem that experts call 'swimmer's itch'. Lyngbya strains are also excellent sources of bioactive secondary metabolites. But their blooms can be hazardous to other life forms on this planet. What is not commonly known is the potential of these strains; insufficient genomic information about them, along with ties they have to other bacteria, have left many researchers perplexed about what they can and cannot do. Fresh information could help researchers develop natural products for treatment. 'These compounds have gained considerable attention due to their pharmaceutical and biotechnology potential, but they are also notorious for their environmental toxicity and threats to humans, wildlife and livestock,' the authors write in the paper. Thanks to this work, which included single-cell genome amplification and metabolite profiling, a complex gene network emerged. This compelled the team to believe that the organism has the capacity to adapt to shifting conditions in the marine environment. The results also pointed to a number of weaknesses of the strain. The team says, for instance, that L. majuscula does not have the genes necessary for nitrogen fixation, despite developments that have emerged indicating that this species fixes nitrogen. 'It's possible that strains of L. majuscula reported to fix nitrogen may have been misidentified, because it is visually very similar to other filamentous cyanobacteria species, and we found that this marine strain doesn't seem capable of fixing nitrogen on its own,' says Emily Monroe, one of the authors of the study and a postdoctoral fellow from the United States' Gerwick laboratory at Scripps Institution of Oceanography, part of the Center for Marine Biotechnology and Biomedicine (CMBB). 'This feature could be a distinction between the freshwater and the marine strains of what is currently characterised as Lyngbya.' Despite these unprecedented findings, more research is needed. Scientists could examine more than 250 compounds that are attributed to marine Lyngbya strains, where around 75?% of those are linked to L. majuscula. The team also discovered that this strain generates just a few natural products. 'This particular strain doesn't produce nearly as many (natural products) as we thought it might, which shows that many of the interesting molecules discovered to date are probably scattered among multiple organisms,' explains first author Dr Adam Jones of the CMBB. 'The lesson learned is that not all marine Lyngbya strains are created equal.' For her part, project coordinator Lena Gerwick of CMBB says: 'This may change the way we start looking at things in the field and give us new ways to identify organisms. We might be able to turn things around and use the compounds they make as a new way of determining what kinds of species they are.' Researchers from Germany's University of Freiburg, the Max Planck Institute (MPI) for Molecular Genetics, and the Genome Centre Cologne at the MPI for Plant Breeding Research contributed to this study.For more information, please visit: PNAS:http://www.pnas.org/Scripps Institution of Oceanography's Center for Marine Biotechnology and Biomedicine (CMBB):http://cmbb.ucsd.edu/
Countries
Germany, United States