Hets are WT and segregate WT, paralysed Dpyunc and dead eggs. Maintain by picking WT.

Heterozygotes are WT and segregate WT, dead eggs and Uncs. At 25C the Unc Spds are Sterile; at 16C the Unc Spds are fertile but produce mostly dead eggs. Unc Spd animals will exhibit a fully penetrant maternal-effect embryonic lethal phenotype if shifted to 25C at the L4 stage. unc-13 spd-2 homozygotes may be propagated at 16C but may become sick causing immense frustration! See also WBPaper00004200.