Figure 8

The conserved G-quadruplex map of MECP2 pre-mRNA orthologs. Conserved G-quadruplexes were mapped to all known alternatively spliced isoforms of MECP2 mammalian orthologs. G-quadruplex locations are highly conserved near alternative splice sites. G-quadruplexes associated with the constitutive splice sites were less likely to be conserved in their locations (data not shown). G-quadruplexes B and B′ overlap each other. The B′ G-quadruplex also overlaps the second 5′ splice site which is alternatively spliced. Four highly conserved G-quadruplexes (marked with arrows as A, B/B′, C and D) were subjected to further sequence analysis. The dotted line before the Rat MECP2 first exon represents an extension of the genomic sequence upstream to the putative transcription start site.