About the strains from C. elegans Knockout Consortium

I am wondering whether the strains made from C elegans Knockout Consortium (“ok” allele) and stored at CGC have been backcrossed into N2 background
to eliminate other possible mutations. Or were they just made by mutagenesis and genotyped for one certain gene knockout allele?

It depends on when the deletion was made. When the consortium first started sending strains out, it was with the understanding that the researcher who requested it would outcross the strain and send it to the CGC for distribution. They then switched to a policy of isolating the mutants and sending them to the CGC without outcrossing - unless it’s a lethal mutation, when in the process of balancing it the mutation was outcrossed once. Usually the listing on the CGC indicates the number of times a strain has been outcrossed. For example, ok205 was outcrossed 5x while ok3139 was outcrossed 1x and ok2000 was outcrossed 0x.

Hope this helps!

Steve

OK~Thanks a lot!