About skn-1

The genotype of the worm strain EU1 I got from CGC is skn-1(zu67) IV/nT1 [unc-?(n754) let-?] (IV;V).
The description is Heterozygotes are Unc and segregate Unc, WT which give only dead eggs, and dead eggs.
Maintain by picking Unc.

I was wondering how I can get skn-1 -/- (homozygous mutant)? What does nT1 [unc-?(n754) let-?] (IV;V) mean.

Thanks a lot!

nT1 is a translocation involving linkage groups IV and V. It is used as a balancer for parts of those chromosomes, including the location of skn-1.

Animals heterozygous for a reciprocal translocation segregate progeny homozygous for the non-translocation chromosomes (1/16), animals homozygous for the translocation chromosomes (1/16), translocation heterozygotes (4/16) and aneuploids (10/16). See Rosenbluth and Baillie for more.

In the case of nT1 [unc(n754) let-?], the translocation chromosomes carry two additional mutations: one that dominantly causes an Unc phenotype, and one that recessively causes a lethal phenotype. The viable nonUnc animals are homozygous for skn-1(zu67) - but note that they’re not nulls, because of maternal rescue.

Thanks for your reply. But I must pick Unc not viable unUnc worms. Is that right?

The Unc animals are skn-1(zu67)/nT1 [unc(n754) let-?]. They are fertile, with the progeny classes in my earlier post.
The nonUnc animals are skn-1(zu67) homozyotes. They should not produce viable progeny, because of maternal-effect lethality.