Genomic organization and mapping of the human and mouse neuronal β2-nicotinic acetylcholine receptor genes

Abstract

Abstract. As a first step in determining whether there are polymorphisms in the nicotinic acetylcholine receptor (nAChR) genes that are associated with nicotine addiction, we isolated genomic clones of the ␤2-nAChR genes from human and mouse BAC libraries. Although cDNA sequences were available for the human gene, only the promoter sequence had been reported for the mouse gene. We determined the genomic structures by sequencing 12 kb of the human gene and over 7 kb of the mouse gene. While the sizes of exons in the mouse and human genes are the same, the introns differ in size. Both promoters have a high GC content (60-80%) proximal to the AUG and share a neural-restrictive silencer element (NRSE), but overall sequence identity is only 72%. Using a 6-Mb YAC contig of Chr 1, we mapped the human ␤2-nAChR gene, CHRNB2, to 1q21.3 with the order of markers cen, FLG, IVL, LOR, CHRNB2, tel. The mouse gene, Acrb2, had previously been mapped to Chr 3 in a region orthologous to human Chr 1. We refined mapping of the mouse gene and other markers on a radiation hybrid panel of Chr 3 and found the order cen, Acrb2, Lor, Iv1, Flg, tel. Our results indicate that this cluster of markers on human Chr 1 is inverted with respect to its orientation on the chromosome compared with markers in the orthologous region of mouse Chr 3.

Identification of Human Epidermal Differentiation Complex (EDC)-Encoded Genes by Subtractive Hybridization of Entire YACs to a Gridded Keratinocyte cDNA Library

“…Mapping results and sizes of the SalI restriction fragments for the S100 genes and CHRNB2 agreed with previous data (Schaefer et al 1995;Wicki et al 1996a,b;Lueders et al 1999). In addition, hybridization with defined fragments of distinct YACs unambiguously established the order of eight newly detected EDC genes.…”

“…G13549), which coincide with 3 of the novel genes. In addition, the localization of all genes and hybridization markers mapped previously to the EDC Mischke et al 1996;Wicki et al 1996a,b;Lueders et al 1999;South et al 1999) has been verified on the SalI restriction map.…”

“…YACs 950 e 2#1 to #11 represent single colonies from the unstable CEPH YAC culture 950 e 2. Specific markers for S100A1, S100A2, S100A8, S100A9, S100A10, S100A11, S100A13, SPRR1B, SPRR2A, SPRR3, LOR, IVL, FLG, THH, CHRNB2, D1S305, D1S1664, D1S2346, D1S3619, D1S3623, D1S3624, D1S3625, D1S3626, D1S3627, D1S3628, 37m2, 37m6, and 37m16 were the same as described previously (Engelkamp et al 1992;Volz et al 1993;Pedrocchi et al 1994;Hudson et al 1995;Mischke et al 1996;Wicki et al 1996a,b;Lueders et al 1999;South et al 1999). Cloned cDNA inserts or fragments of them used as probes that were isolated from the gridded library are listed in Table 5.…”

Haplotypes of four novel single nucleotide polymorphisms in the nicotinic acetylcholine receptor ?2-subunit (CHRNB2) gene show no association with smoking initiation or nicotine dependence

“…Recently, YACs and a BAC were identified [Lueders et al, 1999] that contained CHRNB2, and the BAC also contained marker D1S3626. The structure of the CHRNB2 gene, partial sequence data, and the results of a negative screen for exonic polymorphisms has been published [Rempel et al, 1998].…”

“…The structure of the CHRNB2 gene, partial sequence data, and the results of a negative screen for exonic polymorphisms has been published [Rempel et al, 1998]. After the work reported here was completed, the full sequence of the gene was published [Lueders et al, 1999]. The gene is about 12 kb, has six exons, and introns ranging in size from 183 bp to over 3 kb (intron 5).…”