Breaking the mold: Research teams sequence three fungus genomes

December 21, 2005

Rockville, MD--From garden compost to forest greenery, the mold Aspergillus fumigatus lurks across much of the world. And so does its impact. The most common mold causing infection, A. fumigatus triggers allergic reactions, asthma attacks--and even deadly infections among people with weakened immune systems.

Now, in the December 22 issue of the journal Nature, scientists at The Institute for Genomic Research (TIGR) and their collaborators report the mold's sequenced genome. The genome could lead researchers to A. fumigatus genes with the potential to generate better diagnostics and treatment for fungal infection. "This genome sequence is going to be central for developing tools for effectively managing A. fumigatus infections as they become more prevalent in the aging population," predicts first author William Nierman, a microbiologist at TIGR.

Nierman co-authored two additional Aspergillus genome papers in the same issue of Nature. One describes a genome project on Aspergillus oryzae, a nonpathogenic food industry workhorse that has produced sake (rice wine), miso (soybean paste), and shoyu (soy sauce) for 2,000 years. The third paper reports the genome sequence of model organism Aspergillus nidulans and compares the organism to A. oryzae and A. fumigatus. The work was carried out collaboratively at several institutions in the U.S., U.K., Spain, Japan, France, Brazil, Austria, Switzerland, and Germany. David Denning of the University of Manchester coordinated the projects.

Unlike most fungi, A. fumigatus likes it hot--and hotter. The fungus enjoys an unusual range of temperatures. At home in the compost heap, A. fumigatus tolerates temperatures up to 70 degrees Celsius. The fungus becomes a human pathogen because it's perfectly comfortable at body temperature, 37 degrees C. Altering ambient temperatures in the lab, TIGR scientists tracked gene activity, documenting different A. fumigatus genes that turned on and off, as the environment warmed.

The A. fumigatus genome is 28 Mb in size, consisting of 8 chromosomes bearing a total of almost 10,000 genes. Which genes make the mold virulent? Some 700 A. fumigatus genes significantly differ--or do not even occur--in a similar, yet less infectious fungus, Neosartorya fischeri. Nierman and colleagues are now searching these unique genes for clues to A. fumigatus infectivity.

It's a complex task. Suspect genes encode proteins involved in central metabolic pathways, cell signaling, cell wall biosynthesis, pigment biosynthesis, and secondary metabolite production. In other words, A. fumigatus's virulence genes are likely complex and mixed up with normal metabolic capabilities, Nierman says. He and his colleagues now plan to systematically "knock out," or disable, genes that might make A. fumigatus infectious. Eventually, Nierman adds, this work could lead to better therapies for serious asthma, allergy, and other conditions.
-end-
TIGR's portion of this project was funded by The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The Institute for Genomic Research is a not-for-profit center dedicated to deciphering and analyzing genomes. Since 1992, TIGR, based in Rockville, Md., has been a genomics leader, conducting research critical to medicine, agriculture, energy, the environment and biodefense.

The Institute for Genomic Research

Related Asthma Articles from Brightsurf:

Breastfeeding and risks of allergies and asthma
In an Acta Paediatrica study, exclusive breastfeeding for the first 3 months was linked with a lower risk of respiratory allergies and asthma when children reached 6 years of age.

Researchers make asthma breakthrough
Researchers from Trinity College Dublin have made a breakthrough that may eventually lead to improved therapeutic options for people living with asthma.

Physics vs. asthma
A research team from the MIPT Center for Molecular Mechanisms of Aging and Age-Related Diseases has collaborated with colleagues from the U.S., Canada, France, and Germany to determine the spatial structure of the CysLT1 receptor.

New knowledge on the development of asthma
Researchers at Karolinska Institutet in Sweden have studied which genes are expressed in overactive immune cells in mice with asthma-like inflammation of the airways.

Eating fish may help prevent asthma
A scientist from James Cook University in Australia says an innovative study has revealed new evidence that eating fish can help prevent asthma.

Academic performance of urban children with asthma worse than peers without asthma
A new study published in Annals of Allergy, Asthma and Immunology shows urban children with poorly controlled asthma, particularly those who are ethnic minorities, also suffer academically.

Asthma Controller Step Down Yardstick -- treatment guidance for when asthma improves
The focus for asthma treatment is often stepping up treatment, but clinicians need to know how to step down therapy when symptoms improve.

Asthma management tools improve asthma control and reduce hospital visits
A set of comprehensive asthma management tools helps decrease asthma-related visits to the emergency department, urgent care or hospital and improves patients' asthma control.

Asthma linked to infertility but not among women taking regular asthma preventers
Women with asthma who only use short-acting asthma relievers take longer to become pregnant than other women, according to research published in the European Respiratory Journal.

What are the best ways to diagnose and manage asthma?
A team of experts from The University of Texas Medical Branch at Galveston examined the current information available from many different sources on diagnosing and managing mild to moderate asthma in adults and summarized them.

Read More: Asthma News and Asthma Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.