Overlapping sense/antisense transcripts in the PISD locus. RACE/array profiling of five novel transfrags found within an isoform of the PISD gene (accession no. BC001482), encoding phosphatidylserine decarboxylase, reveals a complex pattern of sense/antisense transcription. For each index transfrag (panels 1-5 and indicated by arrows), the presence of a transcript on either the bottom-sense strand or top-antisense strand, with respect to PISD, was interrogated using two 5′-RACE/array and two 3′-RACE/array assays with RACE primers designed to query for transcription on either strand. The position of the index transfrag is also indicated by the opaque vertical lines in the corresponding group of four RACE maps (5′/3′-RACE on the top and 5′/3′-RACE on the bottom strand). Approximate positions of the 5′- and 3′-ends of the transcripts on the top or bottom strand are indicated as “5′t,” “3′t,” “5′b,” and “3′b.” ChIP-CHIP profiles with anti-cMyc anti-body compared to input control DNA are also shown (Cawley et al. 2004). Two prominent sites at both 5′- and 3′-ends of the PISD gene, together with sites of lower affinity, can be seen.
