Extended Data 5. Translation into 3'UTRs at endogenous loci tends to yield hypomorphs.

CRISPR/Cas9 editing¹⁷ was used to construct the mutations shown. See Supplementary Table 1 for precise nucleotide sequences of all strains. −1/+1 TerByP indicate the loss or gain of one nucleotide relative to the zero frame, generating a frameshift over the stop codon, and translation into the 3'UTR out-of-frame with the coding sequence. For unc-22, “wild type” indicates a lack of twitching, even in 1mM levamisole. For unc-54(Ȓ1,TerByP), “weak Unc” animals were visibly slower than unc-54(+), but faster than unc-54(TerByP). All mutant phenotypes were recessive.