News Reports & Publications

International Team Identifies Patterns of Melanin Production Variation and its Potential Impact on Fungal Pathogen Virulence

Author: Christy Groves

Himeshi Samarasinghe, lead author on the publication, is a student of Dr. Jianping Xu’s research team within McMaster University’s Department of Biology.

Cryptococcus neoformans is an opportunistic human pathogen responsible for the dangerous fungal disease, cryptococcosis.

Although it is known that melanin plays an important role in C. neoformans survival during infection, little is known regarding the patterns of melanin production variation and the potential effects of such variations on virulence.

In a recent publication in Scientific Reports, IIDR trainee Himeshi Samarasinghe of Dr. Jianping Xu’s lab and colleagues from North America, Europe, and Asia quantified the production of melanin from 54 differing C. neoformans strains, originating from environments across the globe. The objective of their study was to assess the contribution of genetic, environmental, and genotype-environment interaction factors on variations in melanin production within their study population.

Their analyses revealed that genetic differences had the greatest effect on the population’s melanin variance (up to 59%) and that genotype-environment interactions affected variance to a lesser extent (up of 43%). In comparison, environmental factors alone were found to contribute relatively little to melanin variance.

Additionally, the study identified correlations between variations in melanin levels and specific changes within the LAC1 gene – an essential component of melanin biosynthesis within C. neoformans.

The team’s study is the first of it’s kind to look at the relationship between natural genetic variation and virulence trait expression in a human fungal pathogen – research that helps to shed light on the origin, evolution, and genetic and environmental impacts of fungal pathogen virulence.

Read the full publication in Scientific Reports.


Christy Groves