Supervised Lowess normalization of comparative genome hybridization data - application to lactococcal strain comparisons

Background: Array-based comparative genome hybridization (aCGH) is commonly used to determine the genomic content of bacterial strains. Since prokaryotes in general have less conserved genome sequences than eukaryotes, sequence divergences between the genes in the genomes used for an aCGH experiment obstruct determination of genome variations (e.g. deletions). Current normalization methods do not take into consideration sequence divergence between target and microarray features and therefore cannot distinguish a difference in signal due to systematic errors in the data or due to sequence divergence. Results: We present supervised Lowess, or S-Lowess, an application of the subset Lowess normalization method. By using a predicted subset of array features with minimal sequence divergence between the analyzed strains for the normalization procedure we remove systematic errors from dual-dye aCGH data in two steps: (1) determination of a subset of conserved genes (i.e. likely conserved gene...

• Type: Journal
• Year: 2008
• Where: BMCBI
• Authors: Sacha A. F. T. van Hijum, Richard J. S. Baerends, Aldert L. Zomer, Harma A. Karsens, Victoria Martin-Requena, Oswaldo Trelles, Jan Kok, Oscar P. Kuipers
• Keywords: BMCBI 2008, Genome, Normalization Methods, Sequence Divergence