Biomedical Engineering Reference
In-Depth Information
pathway gene specifi c primers and their use in multiplex PCR reactions for
the detection of multiple toxigenic and pathogenic fungi from food crop or
plant samples make PCR-based diagnostics a genuine option.
METABOLIC PATHWAY GENES
The genes which are
i
nvolved in secondary metabolite synthesis play
prominent role in disease causing nature of the pathogen or formation of
secondary metabolites like mycotoxins. In fungi these genes are present
in clusters and expression of one gene is dependent on the coexisting
gene present in the cluster. Expression of all the genes is required for the
formation of particular toxin molecule. These gene clusters are highly
specifi c from one toxin chemotype to another toxin chemotype.
First publication of a diagnostic primer pair was taken as time mark
for each species depicted. In many cases, more systems were published
later for the same fungus. Mycotoxin biosynthesis genes used as sequence
source are given in bold (Fig. 1).
IMPORTANT FUNGAL TOXINS AND THEIR
METABOLIC PATHWAYS
Afl atoxins
Modern mycotoxicology began with the discovery of afl atoxins after a loss
of a large number of animals in England in 1961 after the consumption
Figure 1.
Development of PCR-based detection systems in the chronological order for
mycotoxin producing fungi from 1996 until present (Niessen 2007).
