International Mammalian Genome Society

The 16th International Mouse Genome Conference (2002)


D Lambracht-Washington
UT Southwestern Medical Center

Fischer Lindahl K
Howard Hughes Medical Institute, Center for Immunology, University of Texas Southwestern Medical Center

We are studying the genomic organization of the major histocompatibility complex (MHC) in mouse (H2 system, chromosome 17) and rat (RT1 system, chromosome 20). The class I proteins of the MHC are divided in class Ia molecules, which are expressed ubiquitously and present antigens to immune killer T cells, and class Ib proteins with mostly unknown functions. The least studied class I region of the MHC in rat and mouse is the 1 Mb M region. Its central part encodes three class I genes, M6, M4, and M5. Based on the conserved genes flanking this region, the map position of these genes is homologous to a 380 kb area around HLA-A, -G, and -F in the human MHC. The central H2-M region was considered to be silent because M4 and M6 are pseudogenes and no transcripts were detected for M5, which has an open reading frame. The analysis of this region in the closely related rodent, rat, gives us a different status for these genes. All three orthologous rat genes have open reading frames. In a nested RT-PCR approach with RNAs from different tissues, we found transcripts for rat M4, M5 and M6 as well as mouse M5. The transcriptional rate is assumed to be very low. However, transfection of genomic clones carrying the rat M6-M4-M5 gene cluster resulted in good expression of rat class I proteins on the surface of mouse fibroblasts. Further analysis of the genes and their products will aid the search for possible functions.

Abstracts * Officers * Bylaws * Application Form * Meeting Calendar * Contact Information * Home * Resources * News and Views * Membership

Base url
Last modified: Saturday, November 3, 2012