ABSTRACT
<p><b>OBJECTIVE</b>To determine AF172993 sequence is either the complete CDS or a transcript variant.</p><p><b>METHODS</b>RT-PCR was used to amplify the CDS sequence of Plunc, which was subsequently cloned into the pEGFP-N1 eukaryotic expression vector. After bi-directional sequence analysis, the sequence obtained was blasted against the AF172993 sequence, nr database and human genome database.</p><p><b>RESULTS</b>In CDS of the new cloned sequence, the 658 base A in the AF172993 sequence was replaced by C, and the corresponding genetic code was also converted from AAG to CAG, leading to the alteration of the amino acid Gln to Lys. In addition, the base C at the 658 position of the CDS showed perfect match with the base C at 2094188 position in human chromosome 20.</p><p><b>CONCLUSION</b>The base A at the 658 position of AF172993 sequence of Plunc is a mutation site, which alters the coding of the amino acid. AF172993 sequence is actually a transcript variant of Plunc, and the annotation to AF172993 in GenBank database is not correct and need to be revised.</p>