Stephens R, Horton R, Humphray S, Rowen L, Trowsdale J, Beck S
Immunology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK.
J Mol Biol. 1999 Aug 27;291(4):789-99. doi: 10.1006/jmbi.1999.3004.
We have mapped and sequenced the region immediately centromeric of the human major histocompatibility complex (MHC). A cluster of 13 genes/pseudogenes was identified in a 175 kb PAC linking the TAPASIN locus with the class II region. It includes two novel human genes (BING4 and SACM2L) and a thus far unnoticed human leucocyte antigen (HLA) class II pseudogene, termed HLA-DPA3. Analysis of the G+C content revealed an isochore boundary which, together with the previously reported telomeric boundary, defines the MHC class II region as one of the first completely sequenced isochores in the human genome. Comparison of the sequence with limited sequence from other cell lines shows that the high sequence variation found within the classical class II region extends beyond the identified isochore boundary leading us to propose the concept of an "extended MHC". By comparative analysis, we have precisely identified the mouse/human synteny breakpoint at the centromeric end of the extended MHC class II region between the genes HSET and PHF1.
我们已经对人类主要组织相容性复合体（MHC）着丝粒紧邻区域进行了图谱绘制和测序。在一个连接TAPASIN基因座与II类区域的175 kb的细菌人工染色体（BAC）中鉴定出了一个由13个基因/假基因组成的基因簇。它包括两个新的人类基因（BING4和SACM2L）以及一个迄今未被注意到的人类白细胞抗原（HLA）II类假基因，命名为HLA - DPA3。对G + C含量的分析揭示了一个等容线边界，该边界与先前报道的端粒边界一起，将MHC II类区域定义为人类基因组中首批完全测序的等容线之一。将该序列与其他细胞系的有限序列进行比较表明，在经典II类区域内发现的高序列变异延伸至已鉴定的等容线边界之外，这使我们提出了“扩展MHC”的概念。通过比较分析，我们精确确定了在扩展的MHC II类区域着丝粒末端，基因HSET和PHF1之间的小鼠/人类同线性断点。
