Biomedical Engineering Reference
In-Depth Information
have been historically studied, and information at the molecular level
underpinning the biology and the fungal interactions with their host are
becoming available only recently. Understanding the genetic basis of the
fungus-host interactions and identifi cation of specifi c genes involved in
fungal pathogenicity is an ongoing endeavor because of the complexity
of genes involved in fungal infection and disease development. In
addition, the disease development requires coordinated regulation of
gene expression and interaction between thousands of genes within
the fungal genome making it even more challenging to understand the
fungal pathogenicity (Schafer 1994, Oliver and Osbourn 1995, Hamer and
Holden 1997, Knogge 1998). Our current understanding of the nature of
fungus-host interactions has been derived from genetic manipulation
of individual genes and gene products through the construction of null
mutants, gene expression analysis and complete gene characterization.
With the advancements in whole genome sequencing technologies and
the next generation high-throughput sequencing (NGS) technologies such
as 454 genome sequencer FLX system (Roche Applied Science, IN, USA)
and Illumina Genome Analyzer (Illumina Inc. CA, USA), there has been
a rapid increase in the number of fungal genomes available. Availability
of sequenced genomes has provided a unique opportunity to conduct
comparative genomic studies to understand the different life styles of
pathogens, their biology and evolutionary mechanisms (Shendure and Ji
2008, Nowrousia et al. 2010).
The next generation sequencing technologies have also led to the
availability of genomes of a large number of agriculturally important fungi,
facilitating the study of plant pathogens at the genomic scale. In addition,
to translate all the structural genomics data (nucleotide sequences) of the
different fungal pathogens into functional genomics data (determinining the
gene function of each of the ~10,000 genes), requires robust, high-throughput
transformation technique to employ into both forward and reverse genetics
approaches. Once novel/virulence-associated genes are identifi ed using
the comparative genomics approach and subsequently disrupt the gene of
interest from the fungus to check the phenotypes to determine whether it
has any effect on virulence such as reduced or loss of disease symptoms,
etc., then genetic transformation method is the potential tool for functional
genomics. In some cases, the availability of the genomic sequences for both
the fungus and its host plants provide a unique opportunity for the parallel
study of host-pathogen interaction from both organisms using functional
genomics (Jeon et al. 2007).
Transformation technology has been the basic research tool employed in
the study of fungal genes at the molecular level. Transformation techniques
enable stable integration of foreign DNA into fungal genome mainly
