Different exon-intron organization at the 5' part of a mouse class I gene is used to generate a novel H-2Kd-related mRNA.

A cDNA library constructed from liver mRNA of DBA/2 (H-2d) mice has been screened with H-2-specific probes. The nucleotide sequence of one clone (pH-2d-24) indicates that it derives from an H-2 gene with an unexpected exon-intron organization. Nucleotide sequence comparisons suggest that two distinct mRNAs are produced from a single H-2Kd gene by a mechanism involving the use of alternative splicing sites in its 5' region. pH-2d-24 carries an open reading frame encoding a thus-far-undescribed polypeptide product identical to an H-2Kd-molecule, except for the NH2-terminal half of the first domain.