Genomic organization and ASPSs of the hTERT gene. (A) Exon/intron organization of the hTERT gene assembled from [Genbank:AF128893] and [GenBank:AF128894] . Exons are shown as black boxes with numbering above. Start/Stop indicates the beginning and end of the ORF. (B) Schematic drawing of hTERT mRNA ASPSs. Exons are shown as open boxes with numbering inside. Black boxes represent intronic sequences and are cross-hatched to indicate uncharacterised 5' or 3' splice site. The ORF is indicated below each ASPS by arrows. The hTERT ASPSs have been assigned descriptive names: Ins-i, insertion of intronic sequence; Del-e, deletion of exonic sequence; followed by intron/exon number and a range of nucleotides in brackets when the insertion/deletion involves part of an intron/exon, respectively. (C) Formerly used designations: *, **, ***. (D) Sequence of donor and acceptor splice sites. Unspliced sequence is boxed. Range of spliced nucleotides numbered from the first nucleotide of each intron is shown above the sequence.