Judelson lab research: genome evolution

An interesting feature of many oomycete genomes is the presence of substantial repetitive DNA. Most studies have involved Phytophthora, in which genomes vary in size from 6.2 x 10^7 to 2.4 x 10^8 bp and contain 50% or more repetitive DNA. Interestingly, the genome of P. infestans is 3-4 times larger than other members of the genus, raising interesting questions about its structure. Our sequencing study has shown that the expansion of its genome resulted from a proliferation of many different families of repetitive DNA, which in total account for 74% of the genome.

We have characterized the nature of much of this repeated DNA, since this may lead to new molecular tools, reveal the basis of variation between species, and help explain the phenotypic instability of isolates, in which sectoring for growth rate, morphology, virulence, and other traits are reported.

As part of our studies, we have characterized both DNA transposons and retroelements near the mating type locus of P. infestans.

Contribution of transposable elements to heteromorphism between P. infestans chromosomes, including the hAT element, dodo (named after the extinct flightless bird previously found in the beautiful island nation of Mauritius).

We have also studied the genome-wide contributions of Gypsy-like elements, which comprise the bulk of the repeated DNA.

DNA blot of Gypsy family members

Phylogram of Gypsy-1 members within Phytophthora

The number of members per nucleus of this Gypsy
family of retrotransposons varies widely between species of Phytophthora.


Home page 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 Publications Opportunities for graduate study in the lab		Evolution of the Phytophthora genome An interesting feature of many oomycete genomes is the presence of substantial repetitive DNA. Most studies have involved Phytophthora, in which genomes vary in size from 6.2 x 10^7 to 2.4 x 10^8 bp and contain 50% or more repetitive DNA. Interestingly, the genome of P. infestans is 3-4 times larger than other members of the genus, raising interesting questions about its structure. Our sequencing study has shown that the expansion of its genome resulted from a proliferation of many different families of repetitive DNA, which in total account for 74% of the genome. Contribution of mobile elements to the P. infestans genome (from Haas et al.) We have characterized the nature of much of this repeated DNA, since this may lead to new molecular tools, reveal the basis of variation between species, and help explain the phenotypic instability of isolates, in which sectoring for growth rate, morphology, virulence, and other traits are reported. As part of our studies, we have characterized both DNA transposons and retroelements near the mating type locus of P. infestans. Contribution of transposable elements to heteromorphism between P. infestans chromosomes, including the hAT element, dodo (named after the extinct flightless bird previously found in the beautiful island nation of Mauritius). We have also studied the genome-wide contributions of Gypsy-like elements, which comprise the bulk of the repeated DNA. DNA blot of Gypsy family members Phylogram of Gypsy-1 members within Phytophthora The number of members per nucleus of this Gypsy family of retrotransposons varies widely between species of Phytophthora. Back to top Research areas Home page and contact info Publications Graduate Studies

Evolution of the Phytophthora genome