Provisional chromosome assignment of the rat major histocompatibility complex.

Abstract

Somatic cell hybrids between an AKR mouse thymic lymphoma cell line and normal F344 rat spleen cells were isolated in order to assign the rat major histocompatibility complex (MHC) (RT1) to a specific chromosome. Six primary hybrid clones and 3 of their derivatives were examined for expression of the RT1 antigens on the cell surface by the complement-dependent cytotoxicity test and simultaneously for their karyotypes by the Hoechst 33258/quinacrine mustard double staining method. All of these hybrid clones consisted of 2 sets of mouse and 1 set of rat parental cells, with a preferential loss of rat chromosomes. A high degree of concordance was shown between the expression of the RT1 antigen and the presence or absence of rat chromosome 14 in the original 6 hybrid clones. This was confirmed in 1 spontaneous and 2 immunoselected RT1-negative segregants from RT1-positive clones. These results led us to propose that the rat MHC is located on chromosome 14.

A trans-acting major histocompatibility complex-linked gene whose alleles determine gain and loss changes in the antigenic structure of a classical class I molecule.

“…A diagram representing the regions of the rat MHC, RTl, on chromosome 14 (23). Most of the assignments are justified in published reviews (9,10).…”

Chromosomal assignments of 23 biochemical loci of the rat by using rat × mouse somatic cell hybrids

“…G L O l, which is known to be closely linked to rat MHC and RTI and belongs to linkage group IX of rats (Stoic et al, 1980), was assigned to rat chromosome 20. Linkage group IX of rats was first assigned to chromosome 14 (Oikawa et al, 1984). Recently, however, this linkage group was reassigned to chro mosome 20, and it was also reported that there is no linkage between GLOl and ALB, which is located on rat chromosome 14 (Szpirer et al, 1984;Locker et al, 1990;Stoic, 1990a).…”

Chromosomal localization of the rat albumin gene in normal and analbuminemic rats determined by in situ hybridization.

“…Using the somatic cell hybrid technique, Oikawa et al (1983) recently found that the gene of a rat major histocompatibility complex (RT1) was located on chromosome 14. Since the albumin gene locus is known to be linked to the sixth linkage group of the rat (Shumiya and Nagase 1982), like the plasma protein pattern (Gl-1) and a coat color (Hooded, h) (Womack and sharp 1976), our results suggest that the sixth linkage group may be located on chromo- some 2 in the rat.…”