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General and contact information

Howard Judelson's background
education and interests

The oomycetes
learn more about these exciting organisms

The late blight disease
learn more about the problems that P. infestans causes

Research Interests
Ongoing research projects

Other lab members


Promoters and transcriptional networks

Understanding transcription in Phytophthora is a major goal of the lab. This includes understanding the regulation of stage-specific genes and the overall function of the transcriptional machinery. This work integrates the tools of molecular biology, biochemistry, cell biology, and bioinformatics.

Using reporter genes such as GUS or GFP, we have dissected a number of promoters to identify transcription factor binding sites. Results from some of those experiments, using GUS gene with spore-stage promoters, are shown below:

Spatial patterns of expression of several stage-specific promoters, as revealed using transformants expressing the GUS marker gene.

Demonstration that a 7-nt "cold box" is responsible for the induction of genes during cold-induced zoosporogenesis. This sequence was identified through the testing mutagenized versions of the PinfC promoter in transgenic P. infestans.

We have used a variety of methods, including protein-binding oligo microarrays and SELEX sequencing, to identify the binding specificity of most transcription factors from P. infestans. Gel-shift assays (EMSA) are commonly used to confirm these specificities.

EMSA assay for a sporulation-specific transcription factor

We have used a range of bioinformatics strategies for predicting binding sites of transcriptional regulators, integrated with genomics tools for precisely identifying transcription start sites.

Schema used to identify over-represented motifs and mark high-priority candidates for functional analysis.

Spatial distribution of a novel oomycete core promoter sequence.