A class I jumping clone places the HLA-G gene approximately 100 kilobases from HLA-H within the HLA-A subregion of the human MHC

Abstract

By the combination of cosmid cloning, chromosomal jumping, and pulsed-field gel electrophoresis (PFGE), we have fine-mapped the HLA-A subregion of the human major histocompatibility complex (MHC). Through the isolation of a class I jumping clone, the Q alpha-like HLA-G class I gene has been placed within 100 kb of HLA-H. The tight physical linkage of these class I genes has been further supported by hybridizing PFGE blots with locus-specific probes. It has been found that both of the above class I genes are linked to HLA-A, with HLA-H residing no more than 200 kb from the HLA-A gene. These data support the possible existence of a Q alpha-like subregion composed of nonclassical HLA class I genes within the human MHC linked telomerically to the HLA-A locus.

HLA-G UTR Haplotype Conservation in the Malian Population: Association with Soluble HLA-G

“…Numerous non-functional genes (pseudogenes) such as HLA-H can be found between these two genes. Two HLA-A allele groups, HLA-A*23 and HLA-A*24 were previously reported to be associated with a large-scale deletion of 50 kb including the HLA-H pseudogene in the region that precedes HLA-G [37], [38], [39], [40]. The LD between HLA-A and HLA-G alleles may be due to the relatively short genetic distance (and limited recombination events) between them, but may also be the reflection of some, yet unknown, biological constraint.…”

Report of the committee on the genetic constitution of chromosome 6

“…This may also apply to D6S131E, another locus on chromosome 6 with homology to a t-complex gene of the mouse, which has been mapped 2 cM distal to HLA-A and 7 cM proximal to D6S8 in 6p21.3 distal-p22.1 proximal (Blanchd et al, 1991a). Despite the generation of YAC clones and cosmids covering large parts of the class I region (Chimini et al, 1990;Jouet et al, 1991;Shukla et al, 1991;Schmidt and Orr, 1991), only seven expressed genes arc currently known to be located in a stretch of DNA with a length of nearly 2000 kb. However, the situation is entirely different in the class II and class III regions.…”

“…The map is: 'HLA-F'-'HLA-G'-('HLA-H'-'HLA-A')-'HLA-E'-'HLA-C'-'HLA-B'-C6M10-C6M5 (Schmidt and Orr, 1991;Shukla et al, 1991;Chimini et al, 1990;Koller et al, 1989;Ragoussis et al, 1986;Ragoussis et al, 1989;Lawrance et al, 1987).…”

“…It is very likely that HLA-H is situated telomeric to HLA-A, but this issue has not yet been completely clarified. This locus has been shown to be part of a physical map composed of HLA-F, HLA-G, HLA-H, HLA-A (most likely order) as well as several pseudogenes and must therefore also be situated in the chromosome 6p21.3 region like other HLA loci (Shukla et al, 1991).…”

An alternatively spliced form of HLA-G mRNA in human trophoblasts and evidence for the presence of HLA-G transcript in adult lymphocytes.

“…This region includes three subregions ofMHC genes: class I, class II, and class III. The class I subregion is larger than the two others, spanning 2000 kb, and is composed of >20 genes and pseudogenes (1). This class I region comprises two groups of genes: (i) Classical HLA class I genes (HLA-A, HLA-B, HLA-C), highly polymorphic and ubiquitously expressed, encode cell surface 45-kDa glycoproteins associated with an invariant 12-kDa 32-microglobulin chain.…”