Figure 2.

Possible mechanisms of cis-regulated ASE and ASM. The cis-acting effects of sequence polymorphisms can be either short-range (A and B) or long-range (C). Details of each model are discussed in the text. Working out the relevance of each mechanism will depend on developing efficient methods for high-resolution mapping of allelic asymmetries and for determining long-range haplotypes in large collections of primary tissues. Black circles, methylated CpG dinucleotides; white circles, unmethylated CpGs; dark gray rectangle and arrow, first exon of the gene.