Figure 6

Comparative genomic analysis of HOTAIRM1 orthologues in mammals. The genes flanking HOTAIRM1, HOXA1 and HOXA2, from the human genome (chr7:27,132,617–27,142,393; http://genome.ucsc.edu), are shown along with their conservation score (phylop). HOTAIRM1 gene structure consists of three exons in eutherian mammals, but two exons in the tammar (lower left), based on predicted RNA secondary structure and sequence alignment. Phylogenetic trees showing that exon 1 is highly conserved with short genetic distance between them compared to exon 2 and exon 3 consistent with the concept of rapid evolution of non-coding RNAs (lower right).