Fig. 1. Mutation analysis of egl-15 alleles. Alleles are graphically positioned based on the severity of their phenotype (horizontal axis) and the location of their lesion (vertical axis). The axis representing the level of the essential function of EGL-15 signaling activity is portrayed above by the triangle, with minimal activity corresponding to the Let phenotype and near normal activity corresponding to the Soc phenotype. Nonsense mutations are boxed, splice site mutations are represented in parentheses. n1457 and the other egl-15(Egl) alleles break this allelic series. An additional group of mutations isolated as suppressors of clr-1 (Soc) were characterized only in a clr-1(e1745ts) background: n2217(W633Opal), n2182(A650V), n2189(P876L), n2184(G890E), n2203(G871S) and n2206(W930Amber). The full-length EGL-15(5B) type 1 isoform is 1040 amino acids in length.