Key points are not available for this paper at this time.
A When the accession numbers are entered at the National Center for Biotechnology Information home site (http: //www. ncbi. nlm. nih. gov/) they will provide direct links to nucleotide and protein sequences as well as references to the identification of these genes. B UPF3B (XM₀16123) and UPF3X (NM₀23010) appear to represent two additional copies of the UPF3 gene. How they differ in function from the UPF3A gene and transcript is not understood. C The web address for WormBase, the database for C. elegans genome information, is http: //www. wormbase. org/. EST, expressed sequence tag.
Peter H. Byers (2002) studied this question.