Handling: Easy to manipulate. Heterozygous males mate well. Vulvaless homozygous hermaphrodites completely unable to mate. Cause of vulvaless phenotype unknown. Translocation may break down spontaneously, but analysis of such events is lacking. Heterozygous strains occasionally begin to segregate large numbers of sick-looking progeny while appearing to remain heterozygous, or they occasionally begin to give larger broods (Schein and Baillie, unpublished results). nT1[qIs51] carries an integrated pharyngeal GFP element, and is homozygous inviable; this variant appears to be transferred to male cross progeny more frequently than to hermaphrodite cross progeny.