hp684(Q1864X) mutant animals generate reversal movement with little flexing of the posterior body, and the stiffness is prominent during prolonged reversals. This phenotype is progressive, and most prominent when animals develop from the L4 stage larvae into adults. Reference: Chitturi JH, et al. PLoS Genetics. 2018;14(4):e1007303.

Stiff backing. Presumptive null. This strain carries two CRISPR-engineered deletions to ensure complete knockout of ubr-1 function. hp821 is a deletion in the 5 ' end of ubr-1 and hp833 is a deletion near the 3' end of the gene. Reference: Chiturri J, et al. PLoS Genet. 2018 Apr 12;14(4):e1007303. doi: 10.1371/journal.pgen.1007303. eCollection 2018 Apr. PMID: 29649217.