Localization of the acetylcholine receptor γ subunit gene to human chromosome 2q32→qter

Abstract

The nicotinic acetylcholine receptor of skeletal muscle (CHRN in man, Acr in mouse) is a transmembrane protein composed of four different subunits (α, β, γ, and δ) assembled into the pentamer α2βγδ. These subunits are encoded by separate genes which derive from a common ancestral gene by duplication. We have used a murine full-length 1,900-bp-long cDNA encoding the γ subunit subcloned into M13 (clone γ18) to prepare single-stranded probes for hybridization to EcoRI-digested DNA from a panel of human × rodent somatic cell hybrids. Using conditions of low stringency to favor cross-species hybridization, and prehybridization with rodent DNA to prevent rodent background, we detected a single major human band of 30–40 kb. The pattern of segregation of this 30–40 kb band correlated with the segregation of human chromosome 2 within the panel and the presence of a chromosomal translocation in the distal part of the long arm of this t(X;2)(p22;q32.1) chromosome allowing the localization of the γ subunit gene (CHRNG) to 2q32→qter. The human genes encoding the γ and δ subunits have been shown to be contained in an EcoRl restriction fragment of approximately 20 kb (Shibahara et al., 1985). Consequently, this study also maps the δ subunit gene (CHRND) to human chromosome 2q32.1→qter. In the mouse, the Acrd and Acrg genes have been shown to be linked to Idh-1, Mylf(lDHI and MYL1 in humans, respectively) and to the gene encoding villin on chromosome 1. Interestingly, we have recently localized the human MYL1 gene to the same chromosomal fragment of human chromosome 2. These results clearly demonstrate a region of chromosomal homoeology between mouse chromosome 1 and human chromosome 2.

An RFLP map for 2q33‐q37 from multicase mycobacterial and leishmanial disease families: no evidence for an Lsh/Ity/Bcg gene homologue influencing susceptibility to leprosy

“…Combining the mapping information from the different laboratories provides a consensus map for markers around Lsh on mouse chromosome 1 as follows : centromere-Cryg-0.7 cM-Crebl-3.3 cM--Fnl-3.1 cM-Tp-1-0-8 cM-Vil-1-0.3 cM-Des-0.3 cM-Inha-10.2 cM-Acrg-2.1 cM-ColGa3. This is broadly consistent with human in situ hybridization data mapping CRYG to 2q33-q36 (Shiloh et al 1986), CREBl to 2q32-q34 (Taylor et al 1990), FN1 to 2q34-q36 (Jhanwar et al 1986), TNPl ( = Tp-1) to 2q35-q36 (Luerssen et al 1990), VILl to 2q35q36 (Rousseau-Merck et al 1988), DES to 2q35 (Viegas-PBquignot et al 1989), INHA to 2q33-qter (Barton et al 1989), CHRNG ( = Acrg) to 2q32-qter (Cohen-Haguenauer et al 1987) and COL6A3 to 2q37 (Weil et al 1988). Lsh co-maps with (Schurr et al 1989;Malo et al 1991), or is very tightly linked to (Mock et al 1990), Vil-1 in the mouse, with Tp-1 and Des providing proximal and distal boundaries for the segment of chromosome 1 known to carry Lsh.…”

Two Genetic Loci Regulate T Cell–Dependent Islet Inflammation and Drive Autoimmune Diabetes Pathogenesis

“…number of genes without obvious links to diabetes pathogenesis map proximal to D1Mit305 (fig. 5A), including those for the nicotinic acetylcholine receptor, Acrg (Heidmann et al 1986;Cohen-Haguenauer et al 1989); collagen type VI, Col6a3 (Schurr et al 1990); retinal Santigen, Sag (Danciger et al 1989); and the high-density lipoprotein-binding protein, Hdlbp (Xia et al 1993;LeBoeuf et al 1994). At Idd5, as at all other Idd regions, the mapping of expressed sequence tags and defined cod-ing regions is far from complete, so it remains likely that these regions contain genes that have yet to be identified and may include novel genes involved in diabetes susceptibility.…”

Further characterization of a somatic cell hybrid panel: ten new assignments to the bovine genome

“…1980) corresponds to the bovine synteny group U21-Ch19 (O'Brien & Marshall Graves 1991); COLlA2, located on human chromosome HSA7q21.3-q22.1 (Junien et al 1982), may the bovine gene belong to the corresponding bovine U13 and finally CHRNG is situated on the q32-qter region of human chromosome 2 (Cohen-Haguenauer et al 1989), which corresponds to cattle U17. These assignations are in accordance with predictions based on comparative mapping with the human species.…”