dsRNA ingested by bees is transferred to the Varroa mite and from mite on to a parasi

[Ian]

this was pulled from a conversation Randy Oliver is having on Bee-L

>>RNAi treatment for viruses is much like getting a
vaccination. For varroa or nosema, perhaps more like a systemic dog
treatment to kill fleas, but without any toxins involved.<<

[JRG13]

yes and no, you would need it refreshed often unless you're producing the RNAi fragments yourself. I do not know how quickly it's degraded once ingested.

[deejaycee]

Pretty hard to convince people to buy such a thing if they're likely to get it without purchasing it anyway, I think.

From what little I understand at this point, I think you've got the principals of spread about right, though I don't know how persistent the 'treatment' would be... whether there is a certain required 'density' of RNA that might need topping up to continue to be effective... or indeed what the mode of action in the mite would be, and how persistent that might be.

In terms of what it's going to be worth.. this technology is absolutely invaluable in all sorts of fields - think human medicine - and I'm darn sure Monsanto or any other party would have that in their minds as well. But it's going to take a pretty strong proof of concept and safety, etc, to ever get close to that field. Bees could be a valuable testing ground. Not saying you're going to get the tech for free, but there could be a strong incentive in terms of the larger market to get this working in our market.

[JRG13]

I don't think this is an instance of kicking the can further down the road either. If the efficacy was higher I'd be more excited, but 60% effectiveness is really lack luster to me for this kind of technology. If it were in the high 90's I'd be more excited, just think, you could treat with capped brood and still get good kill. There's other applications for this approach as well.

[JRG13]

As of now the price is really high, because producing the RNA is not cheap.

[squarepeg]

would the rna get incorporated in the bee genome and be transmitted to bee offspring? my take from the paper was that it is mite rna, that the bee eats, and then the mite takes it in when it sucks on the bee. once in the mite, it gets incorporated into the mite genome, and the next generation of mite dies of a serious birth defect.

i'm thinking that if the birth defect kills the mite offspring, that birth defect would not be transmitted to any future generations of mites. if so, the only way for the mites to get the killer rna in the first place would be if it was always available in the bees. if newly emerging bees weren't getting it in the food supply, and the bees that had eaten the killer rna are lost by attrition, the killer rna wouldn't be in the new bees for the mites to suck out.

that would suggest that the rna would have to avaible in the bee food at least for every turnover of the bee colonies' population.

the 'trick' is that the bees are vectoring the killer mite rna to the mites, i don't believe it is intended to change the bee's genetics. (altough some have suggested in could, and in unpredictable ways.....)

[Kieck]

The paper cited is clear that dsRNA taken up in feed by bees can be passed by mites into other bees. Just how far that cycle can go, I'm not sure. However, the paper seems to me as if the genes coded in the dsRNA are being transferred into the bees' genomes.

In short, it seems as if these are transgenic (or GMO) bees.

The simplest explanation I can think of for how a mite picks up genes feed to a bee involves incorporation of those genes into the bee's cells. After all, the mites are not tapping into the gut contents of the bees. Mites feed on haemolymph, not fluids in the digestive tract. So the dsRNA has to somehow cross barriers to get out of the digestive system.

[Ian]

In short, it seems as if these are transgenic (or GMO) bees.

your calling these bees GMO bees ?

[squarepeg]

kieck, yes once the mite contracts the rna sequence by sucking the hemolymph from a bee that has eaten the sequence, (the sequence could be thought of as a synthetic 'virus' deadly to mites but not bees), it indeed can be transferred to other bees via the mites. hence the title 'bidirectional transfer'.

the study shows that the sequence is transferred from the bee gut to its hemolymph.

i am going to reread the paper, but i'm still thinking the bee genome is not being targeted.

[squarepeg]

the rna sequence also ended up in brood that were feed by nurse bees who had eaten the sequence, and transferred to mites via sucking on brood.

[squarepeg]

after rereading, i'm convinced the bee genome is not the target for the rna sequence. (with the disclaimor that my background is neurophysiology and not genetics).

affecting the bee genome, or the physiology of the bee in any way, would be considered an 'off target effect', and the authors claim they did not observe any.

[squarepeg]

for what it's worth, randy oliver responded about this technology on another forum, and his take was that these findings are very preliminary, and suggested no one hold their breath waiting to see this hit the market. apparantly there are a lot of regulatory hurdles to overcome before anything like this can be made available to the public.

[Kieck]

Simple version of a viral infection: a virus inserts its genetic material into a cell, and the cell produces proteins and genetic molecules (DNA or RNA) bases on the genes of the virus.

"Transgenic" involves transfer of genes from one organism to another.

Seems to me that putting genes into an organism via a virus qualifies as transgenic. Some of the genes moved from one organism into a crop by humans were (and may still be at times) transferred by using a virus. These organisms are termed "GMOs" by many folks.

I'm not seeing where the distinction lies.

The authors of the paper cited in this thread imply that the dsRNA is analogous to a human-created virus.

[JRG13]

There's no gene transfer. GMO bees would have to have the sequence inserted and then could produce the dsRna's themselves w/o being fed. It's a little similar to virus, but not quite. The Rna simply shuts down expression of targeted genes, in this case a gene the mite needs to survive. The Rna does not self replicate as virus either, once it binds to the analogous rna of the expressing gene, it's essentially used up.

[Ian]

That was well said JRG13

I have been reading some of Randy Oliver's posts to this same topic on another forum
He is actively involved with one of the groups developing this technology
Got a long way to go before anythought of providing it for commercial use

[mac]

Got a long way to go before anythought of providing it for commercial use

My understanding is that some FIELD testing has all ready been done in Fl before Monsanto bought out Beelogic or what ever the developing companies name was. Jerry Hays was involved with these tests and is one of the reasons he now works at Monsanto. He was chief Bee inspector here in Fl. If the rna can be passed on into the bee dna it’s all ready out in the bee population.

[Ian]

its got to go through the regulatory processes ,
that is where the big tickets come into play, very expensive

[Kieck]

The Rna does not self replicate as virus either, once it binds to the analogous rna of the expressing gene, it's essentially used up. -JRG13

After studying up on exactly how dsRNA works and is used in this sort of application, I think JRG13's post is clear and accurate, and squarepeg was right on target, too. I let my ignorance show pretty clearly. The dsRNA is not replicated by any of the organisms, and it apparently degrades quite quickly even outside cells. It seems that it might only be intact for a few days after it has been created and fed to bees.

[Lburou]

...snip...The dsRNA is not replicated by any of the organisms, and it apparently degrades quite quickly even outside cells. It seems that it might only be intact for a few days after it has been created and fed to bees.

That takes care of my concern expressed early in this thread.

[jim lyon]

Good work by all who posted on a subject that is difficult for many of us to grasp. This is Beesource at its best. Incredibly it almost seems as though a consensus has been reached and all of this without any guidance from New York City.