Dear worm community,
Does anyone know of an effective RNAi (by feeding) strategy to generate an otherwise normal, but sterile, germline with no dead embryos. cdc-25 (RNAi)
works well but there is no germline present. FUDR is effective but generates dead embryos. Ideally, we would like a normal germline but infertile animal. We are
about to try fem-2- Does anyone have any other suggestions?
Hopefully someone will say fog-2 RNAi works great, because that would make my life awesome.
I wonder if spe-8 works by RNAi. If you want something as close to normal as possible but no self-progeny it’s arguably better than using Fem or Fog: it makes sperm, and they’re even capable of function, except they’re missing something that can be complemented by mating in wild-type sperm.
There’s nothing about an RNAi phenotype in WormBase that I can see, which isn’t promising. There are a couple of other spe mutants with a similar phenotype you could check, though.
AFAIK, none of the Spe genes is susceptible to RNAi (at least, not any of the ~dozen that I’ve tested). The Mog genes are susceptible but cause embryonic defects. Best bet might be one of the Fog genes. But note that, if successful, oocyte maturation and ovulation will be affected by the absence of sperm.
Murr, I think I remember Diana Chu RNAi depleting sperm components, but that could just be random neurons firing.
Yup, Chu and Meyer 2006 describe RNAi working on sperm genes, along with pers comm from Sam War and Steve L’Hernault that most Spe genes are refractory to RNAi. You could drill down in the Supp figures/tables there to see whether a c=goo candidate presents itself.
Or surely there is a ts Spe somewhere?
@dreiner, your neuron firings are not random. Diana Chu did indeed report that RNAi of gsp-3/4 causes a partially penetrant sperm sterility. A̵n̵d̵ ̵I̵ ̵t̵h̵i̵n̵k̵ ̵C̵r̵a̵i̵g̵ ̵L̵a̵M̵u̵n̵y̵o̵n̵ ̵h̵a̵s̵ ̵i̵d̵e̵n̵t̵i̵f̵i̵e̵d̵ ̵a̵ ̵d̵i̵f̵f̵e̵r̵e̵n̵t̵ ̵g̵e̵n̵e̵ ̵w̵i̵t̵h̵ ̵s̵p̵e̵r̵m̵-̵s̵p̵e̵c̵i̵f̵i̵c̵ ̵s̵t̵e̵r̵i̵l̵i̵t̵y̵ ̵b̵y̵ ̵R̵N̵A̵i̵.̵ [Nope]
There are a number of t.s. Spe alleles, but I assumed the request for RNAi targets precluded a genetic solution to the problem.
Although RNAi might be preferable, a new approach was just pre-printed by Patrick Phillips’ lab. Using the auxin-inducible degron system, they generated a strain to deplete spe-44 in the germline so one can get conditional sterility upon exposure to auxin.
https://www.biorxiv.org/content/biorxiv/early/2018/03/18/284232.full.pdf
We used RNAi of egg-5 quite effectively in our eLife paper (https://elifesciences.org/articles/06259) to block progeny production without affecting the germline.