ISOLATION AND CHARACTERIZATION OF A NOVEL H-2 CLASS I GENE

I类MHC基因家族的高度分化成员M1代表了一个与MHC基因家族的高度分化成员。 原始I类基因的直系后代，早于物种形成。 使用一系列重组和同类小鼠品系，该基因具有 已被映射到染色体17端粒的Qa区域。结合 随着对其他不同I类基因的研究，如编码HMT的基因， M1被用来定义一个新的MHC亚区M。 尽管M1与H-2 I类的其余部分存在广泛的分歧， M1家族中，M1具有开放的阅读框架和合法的剪接位点， 外显子M1似乎含有一个功能性启动子，因为引入了一个 3.4将含有M1的25 kb基因组DNA片段导入小鼠L细胞， 基因的转录。然而，M1不能被检测到转录， 在多种细胞系或成人体细胞组织中，没有M1抗原 被识别。M1的表达受强沉默子控制 位于含有M1基因的16 kb基因组片段内的元件。

A highly divergent member of the class I MHC gene family, M1, represents a direct descendant of a primordial class I gene, which antedates speciation. Using a series of recombinant and congenic strains of mice, this gene has been mapped to a region of chromosome 17 telomeric to Qa. In conjunction with studies of other divergent class I genes, such as those encoding HMT, M1 has been used to define a new MHC subregion, M. Despite the extensive divergence of M1 from the rest of the H-2 class I family, M1 has open reading frames and legitimate splice sites in all exons. M1 appears to contain a functional promoter since introduction of a 3.4 kb genomic DNA fragment containing M1 into mouse L cells results in transcription of the gene. Nevertheless, M1 is not detectably transcribed in a variety of cell lines or adult somatic tissues and no M1 antigen has been identified. Expression of M1 is controlled by a strong silencer element located within a 16 kb genomic fragment containing the M1 gene.