MIC2R: a transcribed MIC2-related sequence associated with a CpG island in the human pseudoautosomal region

Sequences related to exons 1, 4 and 5 of the human pseudoautosomal gene MIC2 have been detected on the X and Y chromosomes of humans and other primate species. Isolation of these sequences has defined a new transcribed locus, MIC2R (MIC2-related) which is associated with the second most proximal CpG-rich island in the human pseudoautosomal region. Genomic sequences from the MIC2R locus show that it is composed of a single sequence related to exon 1 and at least four tandem copies of sequences related to exons 4 and 5 of MIC2. Comparison of the four exon 4- and 5-related sequences suggest that they are the result of sequential duplication of a 2.8 kb region during evolution. Transcripts from the MIC2R locus have been detected in all tissues analysed and a number of different transcripts appear to be generated by alternative RNA splicing. However, as none of the transcripts analysed to date contain a significant open reading frame, the function of the MIC2R locus remains unknown.