Head and shoulders above other genomes

Scientists from Proctor & Gamble, makers of that famous anti-dandruff shampoo that we need not mention here, have successfully sequenced the complete genome for Malassezia globosa (M. globosa), the fungus responsible for dandruff and other skin conditions in humans.

For years, many thought dandruff and seborrheic dermatitis were caused by a different type of fungus (Malassezia furfur). The team from P&G Beauty responsible for the genome also discovered the correct fungal species that was the primary cause of dandruff, the company said in a statement.

The results of the genome sequencing have been published online edition by the Proceedings of the National Academy of Sciences.

Despite the role of M. globosa in dandruff and seborrheic dermatitis,and other common skin diseases such as eczema, atopic dermatitis and psoriasis, little was known about the fungus at the molecular level until this study.

P&G also says that an understanding of M. globosa's genetic make-up may help scientists re-evaluate the parameters that have historically been used to classify fungal organisms.

M. globosa, which is among the smallest of the sequenced free-living fungal organisms, is comprised of around 4285 genes.

A common fungus that lives on the skin of humans, M. globosa feeds off of fatty external lipids. Humans naturally secrete sebum and other lipids onto the scalp, creating a prime environment for M. globosa to thrive.

The average human can host to up to 10 million M. globosa. Symptoms of dandruff and seborrheic dermatitis occur when three factors come together: genetic susceptibility for an inflammatory response, the presence of sebum on the scalp and the presence of M. globosa.

"A complete genomic sequencing of a M. globosa genome opens tremendous opportunities for researchers to understand the interactions of fungi and humans," the study's lead author, P&G Beauty's Dr Thomas Dawson, said.

"It's amazing that the understanding of the genetic make-up of a microscopic organism can have broad implications ranging from human health to agricultural science."

According to P&G, the Malassezia family has a role in a wide range of human health issues.

While M. globosa is related to a host of irritant conditions, other types of Malassezia have been found to be particularly threatening to individuals with early and compromised immune systems, including infants and those suffering from autoimmune diseases.

This fungus family also plays a role in skin and respiratory allergies.

Beyond human health, these findings have agricultural implications, the company said. M. globosa is closely related to multiple common plant pathogenic fungi that cause disease on corn, wheat, and other important food source crops.

Comparative genomic studies are now underway that could lead to new strategies for managing these related crop diseases.