Marine organism reveals hidden secrets that could help fight disease

By Ruth Hendry - 10 May 2011 18:0:0 GMT
Marine organism reveals hidden secrets that could help fight disease

A tropical marine organism, Lyngbya majuscula, has had its genome sequenced for the first time by an international team of researchers led by scientists at Scripps Institution of Oceanography. The research has groundbreaking implications for treatments of several human diseases, including cancer and Alzheimer's disease. This follows on from recent research which shows that L. majuscula produces substances potentially useful in fighting these human diseases.

L. majuscula is a tiny photosynthetic microorganism, known as a cyanobacteria. Cyanobacteria have been around on Earth for at least 2.8 billion years and can be found in almost every environment, from tropical oceans to the fur of sloths. An explosion in the population of ocean dwelling toxin-producing cyanobacteria causes toxic algal blooms, which can harm both humans and animals. However, many cyanobacteria are known to produce substances that are potentially useful in the fight against human diseases.

Despite this, surprisingly little is known about the genetic mechanisms that underpin the creation of these substances. In the paper discussing sequencing of the L. majuscula genome, researchers stated ''These compounds [produced by L. majuscula] have gained considerable attention due to their pharmaceutical and biotechnology potential, but they are also notorious for the environmental toxicity and threats to humans, wildlife and livestock''.

Sequencing the L. majuscula genome will provide valuable insights in the way these natural compounds are produced. The researchers' work showed a complex network of genes, which suggests that the organism is highly adaptable to changing conditions in the marine environment.

However, although L. majascula has been proven to produce many substances with biomedical and pharmaceutical potential, the species comes in many different forms, known as strains. Unlike plants and animals, bacteria can swap genes through a process called bacterial conjugation.

This is the transfer of genetic material between bacteria via a connection between two cells. Bacterial conjugation is beneficial to bacteria, as they can swap genes which confer the ability to produce useful compounds. This process results in bacteria within the same species having different genes, which produce different - potentially harmful or beneficial - substances.

It is unclear which strains of L. majascula produce which substances. The strain sequenced by the researchers, L. majuscula 3L, was found to produce only a small number of substances. Nonetheless, the sequence of this genome is a huge step forward in our study of cyanobacteria. It represents a significant opportunity to discover more about these ancient organisms and their potential benefits to humans.