Approaches for Genetic Discoveries in the Skin Commensal and Pathogenic Malassezia Yeasts.

Giuseppe Ianiri,Joseph Heitman

doi:10.3389/fcimb.2020.00393

Abstract

Malassezia includes yeasts belong to the subphylum Ustilaginomycotina within the Basidiomycota. Malassezia yeasts are commonly found as commensals on human and animal skin. Nevertheless, Malassezia species are also associated with several skin disorders, such as dandruff/seborrheic dermatitis, atopic eczema, pityriasis versicolor, and folliculitis. More recently, associations of Malassezia with Crohn's disease, pancreatic ductal adenocarcinoma, and cystic fibrosis pulmonary exacerbation have been reported. The increasing availability of genomic and molecular tools have played a crucial role in understanding the genetic basis of Malassezia commensalism and pathogenicity. In the present review we report genomics advances in Malassezia highlighting unique features that potentially impacted Malassezia biology and host adaptation. Furthermore, we describe the recently developed protocols for Agrobacterium tumefaciens-mediated transformation in Malassezia, and their applications for random insertional mutagenesis or targeted gene replacement strategies.

Highlights

Specialty section: This article was submitted to Fungal Pathogenesis, a section of the journal Frontiers in Cellular and Infection
Using molecular techniques described in the section Agrobacterium tumefaciens-Mediated Transformation Enables Insertional Mutagenesis and Targeted Gene Deletion in Malassezia, we demonstrated that the horizontal gene transfer (HGT) of the bacterial flavohemoglobin in Malassezia resulted in a gain of function critical for resistance to nitrosative stress and nitric oxide (NO) detoxification (Ianiri et al, 2020)
The most common use of Agrobacterium tumefaciens-mediated transformation (AMT) in fungal research is based on a binary vector system: one A. tumefaciens plasmid contains vir genes required for virulence, and another plasmid, the Ti plasmid—usually it is a binary vector and is the most commonly manipulated by researchers—contains the marker gene between two 25-bp direct repeats that define the T-DNA

Summary

Introduction

Specialty section: This article was submitted to Fungal Pathogenesis, a section of the journal Frontiers in Cellular and Infection. In M. sympodialis, the viral genome includes two dsRNA elements, one of 4.6 kb that encodes an RNA-dependent RNA polymerase and a capsid protein, and one of 1.4 kb that encodes a novel unknown protein predicted to be secreted from the fungal cells and involved in host-pathogen and/or microbial interactions.

Results

Conclusion