Identification of the Best Candidate Gene by Homozygosity Mapping
(A) Schematic representation of regions of homozygosity on chromosome 12 for globozoospermic patients P1–P9. Data were obtained with a GeneChip Mapping 250K StyI SNP Array from Affymetrix (Santa Clara, CA) in accordance with the manufacturer's recommendations. The analyses were carried out at the IGBMC (Strasbourg) Microarray and Sequencing Platform. The graphic representation is a view from homoSNP, developed by F. Plewniak of IGBMC, Strasbourg (software available on request from plewniak@igbmc.u-strasbg.fr). Regions of homozygosity greater than 45 SNPs are shown in blue. The entire chromosome 12 is represented, with the physical localization indicated at the bottom (NCBI36/hg18). Seven of nine patients have a region of homozygosity > 1 million bp centered around 62 Mb on chromosome 12.
(B) Identification of all the genes localized in the smallest common region of homozygosity of P7, between 61.8 Mb and 62.8 Mb . Representation from the NCBI Nucleotide database.
(C) Expression profile of the four genes present in the candidate region as obtained from the geneHub-GEPIS database, showing that DPY19L2 is expressed preferentially in the testis and that testis expression is marginal in the three other genes.