|Paradigm Genetics' TAG-KO(TM) Technology for Gene Discovery and Gene Function Assignment Published in Proceedings of The National Academy of Sciences, USA|
RESEARCH TRIANGLE PARK, N.C., April 10 /PRNewswire/ --
Paradigm Genetics, Inc. (Nasdaq: PDGM - news) today published its Transposon- Arrayed Gene Knock-Out (TAG-KO(TM)) technology, a functional genomics method that can be used to discover and mutate genes in organisms with large genomes in which the sequence is not necessarily known. These results, from research conducted in fungi, were posted on the web-based version of the Proceedings of the National Academy of Sciences of the United States of America (www.pnas.org). The paper, ``Gene Discovery and Gene Function Assignment in Filamentous Fungi,'' authored by a number of Paradigm scientists led by Lisbeth Hamer, Ph.D., Sr. Research Scientist, will appear in the renowned journal's printed version on April 24, 2001.
``Publication of this innovative research in the Proceedings underscores the strength of our fungal research,'' said John A. Ryals, Ph.D., president and chief executive officer of Paradigm. ``The research described in the paper is the subject of a number of patent applications filed by Paradigm relating to the discovery of gene function in microbial species, and we will continue to actively pursue strong intellectual property in this area. Application of this technology may lead to new fungicides, human anti-fungal products and industrial products.''
Functional genomics is about defining gene function. A necessary precursor is gene identification and gene knock-out production. TAG-KO(TM) is significant because the genes in a genome can be mutated very fast without prior knowledge about the gene sequence. The genome-wide mutagenesis is performed by in vitro transposon insertion into genomic libraries. A transposon is a mobile element that can jump into a new location. Sequence information about the insertion sites is acquired by sequencing from the transposon ends. The function of the genes is predicted by bioinformatic analyses in cases where a high level of similarity to already known genes can be found. Knock-out mutants are produced after targeted integration of the mutated gene (from the library) into the genome. Parameters for high frequency targeted in vivo mutagenesis were established in this study and involve the use of large fragments of homologous DNA. Gene function is confirmed by phenotypic analyses of the knock-out mutants.
Paradigm's research demonstrates the creation of a non-biased set of more than 20,000 insertions into the genome of Magnaporthe grisea. More than a third of these insertions reveal known genes and many novel genes have been identified. Several genes involved in pathogenicity are currently being analyzed. TAG-KO(TM) can be used for comparative analysis of similar genes in important crop pathogens, such as Magnaporthe grisea and Mycosphaerella graminicola, the causal agents of rice blast and wheat blotch disease, respectively. In addition, the research demonstrates that insertions into different regions of a gene can be used to modulate the gene expression, a trait that has great prospects for industrial compound production.
``We have industrialized gene identification, gene knock-out production and gene function assignment in filamentous fungi by developing and combining a series of new technologies. We have overcome several of the difficulties of working with this group of organisms, such as the lack of sequence information, the rather large genomes and the low targeted integration rate. Gene knock-out vectors are produced simultaneously with gene identification and targeted in vivo mutagenesis is now highly efficient. As a by-product of gene identification, genome sequence is acquired. We are developing a wide range of phenotyping tools to speed up the functional analyses of novel genes. We believe this method is going to revolutionize the gene discovery process in these and other organisms amenable for TAG-KO(TM),'' says Hamer...