Assignment<footref rid="foot01"><sup>1</sup></footref> of human filamin gene FLNB to human chromosome band 3p14.3 and identification of YACs containing the complete FLNB transcribed region

Abstract

Human filamin gene FLNB encodes a protein which interacts with the cytoplasmic tail of glycoprotein Ibalpha. Here we report on the mapping of the FLNB gene coding region to chromosome region 3p21.1→p14.3 by fluorescence in situ hybridization with YACs from a previously established 3p14–specific YAC contig. By establishing STSs for 5′- and 3′-end-sequences of the FLNB coding region, FLNB was localized centromeric to the translocation breakpoint t(3;6) in 3p14.3 and distal to the translocation breakpoint t(3;8) in 3p14.2 by STS-PCR. Together these results show that the FLNB coding region maps to chromosome region 3p14.3. Furthermore, by STS-PCR analysis two YACs were identified which contain the entire transcribed region of the FLNB gene.Fluorescence in situ hybridization (FISH) and PCR analysis were performed as described earlier (Bardenheuer et al., 1994; Michaelis et al., 1995).As determined by FISH analysis the location of YAC 252c10 containing the 5′-end of the FLNB transcribed region was 3p21.1→p14.3 (Fig. 1). STSs derived from the 5′- and the 3′-sequences of FLNB cDNA were established using primers derived from the mRNA sequence published by Takafuta et al. (1998). The primer sequences used for the contig construction are given in Table 1. Both FLNB primer pairs amplify products of the same length using cDNA or genomic DNA as templates. PCR analysis allowed us to define the STS-content of YACs from a previously established contig for chromosome region 3p14 (Bardenheuer et al., 1994; Michaelis et al., 1995) and to construct a contig containing the entire FLNB coding region and neighboring regions (Fig. 2). This analysis shows that FLNB maps distal to D3S1592 and proximal to D3S1387 and the t(3;6) translocation breakpoint in 3p14.3 (Smith et al., 1993; Michaelis et al., 1995). In addition, the direction of transcription of the gene was found to be from telomere to centromere.Supported by Deutsche Forschungsgemeinschaft, Bonn, and Stiftung VerUm, Munich.