Overlapping sense transcripts in the HLXB9 locus. RACE/array analysis of two non-exonic transfrags (transfrags 1 and 2, depicted by arrows) of the HLXB9 gene, encoding a homeobox protein, is shown. Both 5′- and 3′-RACE/array profiles are shown for each of the two transfrags as 5′/3′-RACE-1 and 5′/3′-RACE-2, correspondingly. Both transfrags are connected together in a novel sense transcript located within intron 1 of HLXB9 on the bottom strand of Chromosome 7. Transfrag 2, however, is also represented as an alternative exon in several novel HXLB9 transcripts. This transfrag is also connected to a distant downstream region located ∼16 kb away. The maps of cloned RT-PCR products representing different alternative isoforms of transcripts containing novel exons are shown at the bottom.
