Nucleotide and deduced amino acid sequence of the Smn cDNA. The deduced amino acid sequence beginning with the initiating methionine is given. Numbering of nucleotides and amino acids is shown at the right. (▾) Positions of introns; a potential polyadenylation signal (ATAAA) in the 3′ UTR is underlined; (▵) the position of the DNA variants in exons 2a, 3, and 7 of human SMN. The polymorphic variants identified in SPRET/Ei DNA in exons 2b and 7 are indicated above the Smn sequence. Several other variants were also identified in exon 8 but are not shown because of multiple-base changes. The entire Smn cDNA sequence has been confirmed by comparison with the sequence of genomic DNA from the 129/SvJ strain. The GenBank accession no. is U77714.
