Fig 1. Genomic alignment of SMPD1 splice-isoforms in human leukocytes.

(A) Black boxes represent protein coding exonic regions identical to ASM-1. Grey boxes indicate altered amino acid sequence and white boxes sequence of untranslated regions (UTR). Fine lines are intronic sequence. Arrows indicate PCR oligonucleotides. Novel splice-isoforms are marked with an asterisk and candidates for nonsense-mediated mRNA decay with NMD. Numbers below indicate nucleotides added or deleted from the transcript by alternative splice sites deviating from ASM-1. (B) Relative splice-isoform frequencies (log scale) in the human leukocytes cDNA pool based on cloned and sequenced PCR products depicted in (A).