Genome of marine organism reveals hidden secrets

An international team of researchers led by scientists at Scripps Institution of Oceanography at UC San Diego has deciphered the genome of a tropical marine organism known to produce substances potentially useful against human diseases.

 
Coauthors of the paper include (from left) William Gerwick, Emily Monroe, Adam Jones, Lena Gerwick, Sheila Podell and Eduardo Esquenazi.

Tiny photosynthetic microorganisms called cyanobacteria are some of the oldest forms of life on the planet. At times their emergence as toxic blooms causes a threat to humans and animals. But despite the recognized capability of marine strains of the cyanobacterial genus Lyngbya, and specifically the species L. majuscula, to create hundreds of natural products with biomedical promise, surprisingly little is known about the genetics underlying their production.

In this week's online early edition of the Proceedings of the National Academy of Sciences, a research team led by Scripps graduate student Adam Jones and postdoctoral fellow Emily Monroe, both in the Gerwick laboratory at Scripps Institution of Oceanography's Center for Marine Biotechnology and Biomedicine (CMBB), provide the first insights of the genome of Lyngbya majuscula 3L, a Caribbean organism that generates compounds that are being developed for potential treatment against cancer and neurodegenerative diseases.

''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 note in their paper.

In the marine environment the wiry, or ''filamentous,'' cyanobacteria play a vital role in the global carbon cycle. Lyngbya strains are known to disrupt the healthy growth of coral reefs and are behind the agents responsible for a skin rash known as ''swimmer's itch.''

 
Adam Jones collects samples in Papua New Guinea.
Achieving the first genomic sequencing of its kind for the filamentous Lyngbya majuscula 3L, the research team overcame several obstacles due to the organism's complex, intermeshed growth in the wild with a range of other bacteria, muddying a clear picture of the genome. The team undertook several different research tactics and experiments, including single cell genome amplification, protein and metabolite profiling.