N2 worms with defective gonads

Model Organism: Worms Scientific Discussion
1

Hi all,

I’ve noticed some defective worms in the N2 plates that have sick or no gonad al all. These worms look like L4, with a white croissant and no eggs, although they are adults. Some of them lay eggs, but most of these eggs don’t hatch. When I started seeing these worms, they were only a few in each plate, but it seems I’ve enriched the phenotype in some way.
I thought it could be the plates (missing cholesterol or something else…), or some contamination, but some of my lines don’t have this phenotype, and all the lines I have been crossing with N2 look the defective, so I assume that the issue is with the N2 strain. Has anybody seen this phenotype before? Do you know what is causing it? Any solution to get rid of it? We have thawed a new N2 stock, but it would be good to know more about this phenotype to try to avoid it in the future…

Thanks!

2

infertility is one of the most common loss-of-function phenotypes, so it is probably a spontaneous mutation. it happens fairly frequently when passaging N2 stocks over time. good idea to thaw out a fresh stock (or get it again from the CGC) and immediately freeze back a bunch of tubes for future use as reference. it might be that it has a maternal effect and/or temperature sensitivity (depending on how you are passaging), so you could have picked from a plate that had many homozygotes and enriched that way. or, if you passage by picking L4s every time you will artificially select for mutations that cause slow growth, which could be pleiotropic and also cause sterility/embryonic lethality…