Fungal Genomics

3.1 Introduction

Genomics is defined as the study of an organism’s complete genome sequence.

The first complete (nonviral) genome to be sequenced was the bacterium

­Haemophilus influenzae in 1995. Today, more than 78,990 bacterial genomes

have been sequenced or resequenced (source Genome Online Database;

­Table 3.1). Baker’s yeast (Saccharomyces cerevisiae) was the first eukaryote

to have its genome completely sequenced (released 1996). Since then, over

20,000 eukaryote genomes have been completed or resequenced, including our

own (in 2001). Because of their relatively small genome size, roles as human/

crop pathogens, and importance in the field of biotechnology, approximately

three‐quarters of all available eukaryote genome data belongs to the fun-

gal kingdom. Some species, such as S. cerevisiae, have actually had over 400

strains sequenced at the time of writing. The majority of fungal species that

have been sequenced belong to the Ascomycota phylum; furthermore, there is

a significant bias towards species that are pathogens of humans. Reduced costs

and continued improvements associated with new sequencing technologies (see

Section 3.2) should mean that a wider range of evolutionarily, environmen-

tally, and biotechnologically interesting organisms will become available in the

coming years.

This abundance of genomic data has moved the fungal kingdom to the fore-

front of eukaryotic genomics. While some of the species sequenced are closely

related, others have diverged one billion years ago. This enables us to use fungi

to study evolutionary mechanisms associated