Figure 4.—

Molecular characterization of such-1(t1668). (A) Mapping of such-1(t1668): SNP mapping positioned such-1(t1668) between 10.77 cM and 11.51 cM on the right arm of LGIII. The such-1 mRNA contains 12 exons. (B) Schematic representation of exons 6 and 7 and of the intervening intron 6 in wild-type and such-1(t1668) animals, as well as image of relevant RT–PCR products. In the wild type, the most prevalent mRNA species is one in which intron 6 is spliced out (lane 1, bottom band, small mRNA). By contrast, in such-1(t1668), the most prevalent mRNA species retains intron 6 (lane 2, top band, large mRNA). This change in ratio is due to the fact that the small mRNA is degraded in such-1(t1668) embryos by the NMD pathway, since the small mRNA prevails in such-1(t1668) smg-2(e2008) animals (lane 4).