A 2.8 MB YAC CONTIG IN 11Q12-Q13 LOCALIZES CANDIDATE GENES FOR ATOPY - FC-EPSILON-RI-BETA AND CD20

An important locus for Atopy (familial asthma, hay fever and eczema) h as been localized to the 11q12 - q13 region with the minimum recombina tion fraction around the CD20 gene. We have constructed a 2.8 megabase (Mb) Yeast Artificial Chromosome (YAC) contig of the candidate region using 15 STSs. A total of seven genes have been mapped within this in terval in the order cen-OSBP-TCN1-GIF-Fc epsilon RI beta-CD20-CD5-PGA- q(ter) and can be covered by a minimum of eight YAC clones. Contig int egrity was assayed with fluorescence in-situ hybridization (FISH) and the mapping of YAC ends on somatic cell and radiation hybrid panels. A long range restriction map of the contig has been constructed to esta blish the order of and distance between loci. Two promising candidates for the atopy locus, the beta subunit of the high affinity immunoglob ulin E receptor (Fc epsilon RI beta) and CD20, a molecule involved in B cell differentiation, have been placed within the contig.