May Lab Objectives

1
May Lab Objectives

• Evolutionary analysis of the I2 R-gene family
• Mapping of I2 homologs in tomato and potato
  genomes.
• Web presentation of BioInformtic tools and
  educational presentation

2
Project Progress

• Sampling of I2-like NBS-LRR sequences from the
  Solanaceae
• Phylogenetic analysis of the NBS region
• Mapping of I2 sequences
• Informatic tools and data presentation on the web

3
Sampling of I2-like NBS-LRR sequences from the
Solanaceae

• The NBS region was sequenced from 328 clones from
  six species (eggplant, S.demissum, potato,
  pepper, tobacco and tomato).
• 218 unique sequence types were identified.
• These sequences fall within 66 phylogenetic
  clades.

4
Phylogenetic analysis of the NBS region from
sampled sequences

• I2 sequences maintained through speciation events
• 12 million years
• NBS region of I2
• Purifying selection characterizes the evolution
  of the NBS region.
• Positive selection characterizes evolution of 8
  codon positions.

5
Mapping of I2 sequences

• Three lineages map to common genomic locations
  due to cross-hybridization.
• Allele-specific oligo probes identified BAC
  clones containing distinct I2 sequences.
• Single copy BAC ends are being mapped or assigned
  to FPC contigs

6
BioInformtic tools and educational presentation

• Modification of ATV
• Interactive access to data and results
• Integration of phylogenetic and genomic data
• Instructional resources planned

7
Supplementary Data
8
I2 Lineages Map to Common Regions on Chromosomes
8 and 11
9
BAC Contigs Containing I2 Sequences

• 250 clones I2-positive
• 73 clones within 32 contigs
• 6 contigs associated with markers
• 1 contig associated with a mapped marker
  (Chromosome 11)

10
I2 Lineage-specific Oligonucleotide Probes
11
Oligonucleotide Probes Resolve BACs Containing
Specific I2 Lineages
12
ATV Screen Shot of I2 Phylogeny
13
ATV Screen Shot of Phylogenetic and EST
Expression Data
14
Screen Shot of Sample Tomato Mapping Data