Figure 1.

Schematic representation of the first intron of eutherian Impact. The GenBank accession number and length are listed to the right of the common names. Horizontal lines show the relative lengths of the first intron. All sequences begin with GT and end with AG. Short vertical lines and gray boxes represent single CpG sites and CpG islands, respectively, which were detected by GrailEXP 3.31. Characteristic tandem repeats are exclusively found in the CpG islands of murids (mouse, rat, and wood mouse). Glires species are sorted by NCBI Taxonomy ID. The Impact gene is assumed to be imprinted in Glires species [GenBank:EF470590-EF470605] but not in other species [GenBank:AY574202-AY574212]. Asterisks indicate species whose monoallelic expression or methylation of the Impact gene have been experimentally confirmed [12,17].