Comparative genomic resequencing
The present invention is an improved method of resequencing DNA using microarrays to rapidly map and identify SNPs, deletions and amplification events present in the genome of an organism. The method is performed by hybridizing a reference and a test genome to two separate arrays with each array exhibiting a specific intensity pattern. The intensity differences between the reference and the test genome arrays are used to produce a mutation map. The mapped differences are resequenced on a set of resequencing arrays to identify specific genetic mutations.
1. A method for identifying genetic mutations in a test genome of an organism relative to a reference genome of the an organism, the method comprising the steps of:
a) hybridizing the reference genome and the test genome in separate hybridization reactions to a genomic tiling array that comprises a plurality of probes that tile the reference genome across a plurality of regions having a stagger of more than one nucleotide to produce a reference intensity pattern and a test intensity pattern;
b) identifying in the plurality of regions a subset of regions of possible genetic mutation in the test genome in which the test intensity pattern differs from the reference intensity pattern; and
c) resequencing the subset of regions of possible genetic mutation in the test genome on a resequencing array.
2. The method of claim 1 wherein the test genome is haploid.
3. The method of claim 1 wherein the test genome is a Salmonella enterica ty21a genome.
4. The method of claim 1 wherein the test genome is a haploid preparation of a diploid genome.
5. The method of claim 1 wherein the regions that span more than one nucleotide tile the reference genome with a stagger of seven nucleotides.
6. The method of claim 1 wherein the resequencing array includes a probe for each possible nucleotide at each nucleotide position in each region in the subset.
7. The method of claim 1 wherein the genetic mutation is a single nucleotide polymorphism.
8. The method of claim 1 wherein the genetic mutation is an insertion.
9. The method of claim 1 wherein the genetic mutation is a deletion.
10. The method of claim 1 wherein the genetic mutation is an inversion.