Comparative structure of two duplicated T1a class I genes (T10c and 37) of the murine H-2d MHC. Implications on the evolution of the T1a region.
The class I Ag encoded in the Qa/T1a regions of the murine MHC are much less polymorphic, and usually have a more restricted tissue distribution than the classical histocompatibility class I Ag, encoded by genes located in the H-2K, D, and L loci. The isolation of a quasi-ubiquitously expressed, poorly polymorphic class I gene of the T1a region of the H-2d mouse MHC, namely gene 37 (or T18d), has been recently reported. We describe the nucleotide sequence of a closely related gene, T10c gene, the counterpart of the gene 37 in the large duplicated parts of T1a region of the BALB/c (H-2d) MHC. The T10c gene structure and sequence are very similar to those of gene 37, but T10c gene is most likely a pseudogene. In A/J mouse strain, there appears to be a single gene related to 37, which is also found expressed in a variety of tissues. We show that this gene is likely to be a chimeric one derived from T10c for its 3' part, and from a gene closely related to gene 37 for its 5' part, which potentially encodes for an unusual class I molecule composed of the first two domains. Finally, Southern blot analysis of a number of wild mice and related animals suggests that a gene closely related to the present T10c gene may be the ancestor of this subfamily of class I genes characterized by the presence of an unusual second domain.
Nakayama
K
K
Laboratory of Molecular Regulation of Aging, Institute of Physical and Chemical Research, (RIKEN), Ibaraki, Japan.
Tokito
S
S
Jaulin
C
C
Delarbre
C
C
Kourilsky
P
P
Nakauchi
H
H
Gachelin
G
G
D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D015139:Blotting, Southern; D015342:DNA Probes; D005796:Genes; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D008285:Major Histocompatibility Complex; D051379:Mice; D008815:Mice, Inbred Strains / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D012150:Polymorphism, Restriction Fragment Length; D015183:Restriction Mapping
D015342:DNA Probes; D015395:Histocompatibility Antigens Class I; C063371:histocompatibility antigen 37; C063372:histocompatibility antigen T10c