Nav: Home

Scientists crack genome of superfood seaweed, ito-mozuku

March 14, 2019

Along the tropical coastline of Okinawa, Japan, farmers raise rows of delectable seaweed and harvest thousands of tons of the crop each year. Unfortunately, scientists predict that pollution and rising ocean temperatures will blunt this impressive yield, forcing farmers to adopt new cultivation techniques. Recently, scientists at the Okinawa Institute of Science and Technology Graduate University (OIST) decoded the genome of the popular brown seaweed ito-mozuku (Nemacystus decipiens), providing data that could someday be critical to local farmers.

The study, published March 14, 2019 in Scientific Reports, presents the world's first draft genome of ito-mozuku. Just three years ago, the unit released the first draft genome of another local species of edible seaweed, Cladosiphon okamuranus, called Okinawa mozuku. Both seaweed species contain exceptionally high concentrations of fucoidan, a slimy substance thought to stymie the formation of blood clots and cancerous tumors, among other health benefits. The researchers have spotted which genes drive up this fucoidan concentration, a discovery that could have applications in the health food industry.

Besides revealing genes that imbue mozuku with health benefits, the research could be useful for farming.

"My future plan is to establish new methods for cultivation of this species," said Dr. Koki Nishitsuji, first author of the study and a staff scientist in the OIST Marine Genomics Unit, led by Prof. Noriyuki Satoh. Nishitsuji is now working to develop genetic markers to distinguish ito-mozuku from its close cousin.

"Using those markers, we can do cross-breeding," he said. "This is a popular method for making new varieties of land plants, especially wheat and potatoes, but in the case of seaweed, no one has succeeded in cross-breeding."

The Marine Genomics Unit conducted their study with the help of the Onna Fisheries Cooperative, an organization based just around the corner from OIST campus. The group established the "Onna-1" strain of ito-mozuku in 2006 and provided samples for the genome study. The Unit plans to continue sequencing samples from the Cooperative, but someday, they hope to extend their research even further.

"So far, we plan to continue our 'seaweed project' in Okinawa," said Nishitsuji. "If possible, we would like to expand it to cover all of Japan."

Fucoidan Factories

Compared to other brown seaweeds, such as kombu (Saccharina japonica) or wakame (Undaria pinnatifida), both ito-mozuku and Okinawa mozuku are incredibly rich sources of fucoidan. The reason why might be coded in their genes.

The researchers found that both mozuku species contain a fused gene that drives their fucoidan production. On their own, the two genes code for two separate enzymes--proteins that facilitate chemical reactions and ultimately help produce fucoidan. Once fused, the genes can be expressed simulataneously and produce a single enzyme equipped with two functions. Armed with a double-edged enzyme, mozuku likely pumps out fucoidan in a fraction of the time it takes other seaweeds, Nishitsuji said.

The researchers uncovered an additional pair of fused genes in ito-mozuku that they didn't find in Okinawa mozuku. They predict that, when expressed, these genes may boost the number of sulfate groups transferred to fucoidan, a chemical reaction that may be key to the substance's health benefits. The unit plans to put this theory to the test in future studies, as they continue to collect genomic data from brown seaweeds across Okinawa and greater Japan.

"Land crops have a long history of genetic study," said Nishitsuji. "But no one has pursued this kind of research in seaweed." Knowing the cultural and economic importance of the crop in Japan, the Marine Genomics Unit aims to bring our understanding of seaweed up to speed.
-end-


Okinawa Institute of Science and Technology (OIST) Graduate University

Related Genome Articles:

A close look into the barley genome
An international consortium, with the participation of the Helmholtz Zentrum München, Plant Genome and Systems Biology Department (PGSB), has published methodologically significant data on the barley genome.
Barley genome sequenced
Looking for a better beer or single malt Scotch whiskey?
From Genome Research: Pathogen demonstrates genome flexibility in cystic fibrosis
Chronic lung infections can be devastating for patients with cystic fibrosis (CF), and infection by Burkholderia cenocepacia, one of the most common species found in cystic fibrosis patients, is often antibiotic resistant.
A three-dimensional map of the genome
Cells face a daunting task. They have to neatly pack a several meter-long thread of genetic material into a nucleus that measures only five micrometers across.
Rhino genome results
A study by San Diego Zoo Global reveals that the prospects for recovery of the critically endangered northern white rhinoceros -- of which only three individuals remain -- will reside with the genetic resources that have been banked at San Diego Zoo Global's Frozen Zoo®.
Science and legal experts debate future uses and impact of human genome editing in Gender & the Genome
Precise, economical genome editing tools such as CRISPR have made it possible to make targeted changes in genes, which could be applied to human embryos to correct mutations, prevent disease, or alter traits.
Genome: It's all about architecture
How do pathogens such as bacteria or parasites manage to hide from their host's immune system?
Accelerating genome analysis
An international team of scientists, led by researchers from A*STAR's Genome Institute of Singapore and the Bioinformatics Institute, have developed SIFT 4G (SIFT for Genomes) -- a software that can lead to faster genome analysis.
Packaging and unpacking of the genome
Single-cell techniques have been used to investigate histone replacement and chromatin remodeling in developing oocytes.
The astounding genome of the dinoflagellate
Dinoflagellates live free-floating in the ocean or symbiotically with corals, serving up -- or as -- lunch to a host of mollusks, tiny fish and coral species.

Related Genome Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Don't Fear Math
Why do many of us hate, even fear math? Why are we convinced we're bad at it? This hour, TED speakers explore the myths we tell ourselves and how changing our approach can unlock the beauty of math. Guests include budgeting specialist Phylecia Jones, mathematician and educator Dan Finkel, math teacher Eddie Woo, educator Masha Gershman, and radio personality and eternal math nerd Adam Spencer.
Now Playing: Science for the People

#517 Life in Plastic, Not Fantastic
Our modern lives run on plastic. It's in the computers and phones we use. It's in our clothing, it wraps our food. It surrounds us every day, and when we throw it out, it's devastating for the environment. This week we air a live show we recorded at the 2019 Advancement of Science meeting in Washington, D.C., where Bethany Brookshire sat down with three plastics researchers - Christina Simkanin, Chelsea Rochman, and Jennifer Provencher - and a live audience to discuss plastics in our oceans. Where they are, where they are going, and what they carry with them. Related links:...