Alternative polyadenylation sites in the MID1 mRNAs of human (PAS1–PAS4) and rat (rPAS1–rPAS3). (A) The 3'UTR of human MID1 containing alternative polyadenylation sites identified in this study together with data on mRNAs, ESTs and conservation obtained from the UCSC genome browser March 2006 assembly. Regulatory motifs are highlighted in different colors. (B) Ethidium bromide gels of 3'RACE experiments. Locations of primers are indicated in the cartoons (arrows). Asterisks indicate unspecific products. PAS3 and rPAS3 are homologues. The nucleotide sequences of novel 3'ends have been submitted to Genbank with accession numbers EF217423, EF217424, EF217425, EF217426, EF217427, EF217428, and EF217429. The position of the northern probe nbPAS4 is indicated.