Bees transfer virus to varroa mites.

[Hivemaker.]

Seen on BEE-L.


Bidirectional Transfer of RNAi between Honey Bee and Varroa destructor: Varroa Gene Silencing Reduces Varroa Population


Acquisition of RNAi components (dsRNA, siRNA) by ingestion and their spread within the recipient organism has been previously reported by us and others. Here we extend such observations, demonstrating cross-species horizontal transmission of dsRNA which, upon transmission from one organism to another still retains its biological activity. We show that dsRNA ingested by honey bees is further transmitted to the parasitic mite Varroa destructor that feeds on the honey bee's hemolymph. Reciprocally, dsRNA-carrying Varroa transmits the dsRNA back to bees. Furthermore, we demonstrate that bees ingesting dsRNA of Varroa gene sequences become vectors of dsRNAs, transmitting the signals to the Varroa, thus engendering silencing of mite genes and resulting in a significant phenotype, Varroa mortality. The exchange of active silencing signals between the honey bee and the mite suggests a potential RNA-based interaction between invertebrate hosts and parasites. Furthermore, our results offer a potentially conceptually new control measure for the mite Varroa destructor, which is one of the greatest threats to apiculture.

http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003035

 

[domino]

Good stuff. Feed RNA bullets to bees, mites shoot themselves.

50% reduction in varroa in the treated hives within 3 months. Appears harmless to bees and doesn't need chemicals.

 

[pargyle]

Seen on BEE-L.


Bidirectional Transfer of RNAi between Honey Bee and Varroa destructor: Varroa Gene Silencing Reduces Varroa Population


Acquisition of RNAi components (dsRNA, siRNA) by ingestion and their spread within the recipient organism has been previously reported by us and others. Here we extend such observations, demonstrating cross-species horizontal transmission of dsRNA which, upon transmission from one organism to another still retains its biological activity. We show that dsRNA ingested by honey bees is further transmitted to the parasitic mite Varroa destructor that feeds on the honey bee's hemolymph. Reciprocally, dsRNA-carrying Varroa transmits the dsRNA back to bees. Furthermore, we demonstrate that bees ingesting dsRNA of Varroa gene sequences become vectors of dsRNAs, transmitting the signals to the Varroa, thus engendering silencing of mite genes and resulting in a significant phenotype, Varroa mortality. The exchange of active silencing signals between the honey bee and the mite suggests a potential RNA-based interaction between invertebrate hosts and parasites. Furthermore, our results offer a potentially conceptually new control measure for the mite Varroa destructor, which is one of the greatest threats to apiculture.

http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003035

In English anyone ? I read the abstract as well - feeding bees with double stranded RNA renders Varroa ineffective or kills them when they ingest the bees hemolymph ?

Ribonucleic acid (RNA) is a ubiquitous family of large biological molecules that perform multiple vital roles in the coding, decoding, regulation, and expression of genes. Together with DNA, RNA comprises the nucleic acids, which, along with proteins, constitute the three major macromolecules essential for all known forms of life.

So... is it GM if the bees are fed this stuff ? And ... if it gets into the bees hemolymph simply by the bees eating it where does the RNA eventually end up ? In the honey ?

Well ... if it does then I suppose honey eaters have nothing to worry about getting infested with Varroa !

 

[Hivemaker.]

It is early days of course, but the line of research looks to be very promising.

 

[Skyhook]

Please keep us updated- with translations if possible, for those of us not so fluent in the lingo.

 

[Hivemaker.]

Please keep us updated- with translations if possible, for those of us not so fluent in the lingo.

The link i added is coming up in English on my computer, no idea why it is not doing the same on yours, maybe you could try it on Google translate and see if that works.

 

[domino]

Please keep us updated- with translations if possible, for those of us not so fluent in the lingo.

They are saying they want to use a well know process where gentic material flows between plants and animals to feed genetic material to bees that is passed to varroa when they drink bee blood. Once inside the varroa it turns off key processes in the mite that kills it.

In the test they show that in three months this reduce mites by 50% without harming bees.

 

[simoncav]

The use of modified RNA as a means of disrupting Varroa development is something that Dr Alan Bowman and others are working on at Aberdeen University in conjunction with Vita. They are undertaking trials this spring on colonies of bees to test the efficacy.

There is more detail with hopefully a simpler explanation in my blog here.

 

[alanf]

Citation 24 is to a paper by Alan Bowman and colleagues of Aberdeen University. http://www.parasitesandvectors.com/content/pdf/1756-3305-3-73.pdf He gave a talk at the National Honey Show. Most of this video http://www.youtube.com/watch?v=fr6xSSdrrgw is general background on varroa and bees but at around 1:20 there's a brief explanation of the work they did on gene knockdown in varroa mites. Gene knockdown is where you add extra genetic material that turns off the working of some genes. Essentially, gene code in the cell is DNA, a variant called RNA is produced from the DNA pattern and used to make proteins. If you can introduce extra RNA of a related sequence to where this protein production is going on it invokes a mechanism called double-stranded RNA-interference, a form of gene knockdown or gene silencing. Stop a specific gene producing a vital protein and you harm, maybe kill, the organism. The real bonus is that this can be made specific to the one form of gene you target, i.e. the mite version, not the bee version.

What the Bowman paper showed was that gene knockdown not only worked in mites but that one potential delivery mechanism was soaking the varroa mites in a saline solution of the RNA. Some potential, but not an obvious delivery mechanism in a hive.

The Gerbian paper demonstrates that virus RNA can transmit food to bee and bee to mite and remain active. So we have the potential to feed the bees RNA which they transmit to mites. Hence the claim in the abstract that:

The exchange of active silencing signals between the honey bee and the mite suggests a potential RNA-based interaction between invertebrate hosts and parasites. Furthermore, our results offer a potentially conceptually new control measure for the mite Varroa destructor

Still a long way to go on confirming the best genes to target and getting your manufactured RNA delivered to the mites as a mechanism in the field. Not to mention how you could manufacture RNA in quantity. But small steps.

 

[Chris B]

Very interesting.
And if treated bees get robbed, the robbers end up with a free varroa treatment as well as a free feed.
What really appeals about a feed based treatment is that it's effective for 6 months or more.

 

[DanBee]

Still a long way to go on confirming the best genes to target and getting your manufactured RNA delivered to the mites as a mechanism in the field. Not to mention how you could manufacture RNA in quantity. But small steps.

Indeed. We have a means to interfere, a mechanism to deliver the interference, but we don't yet know what to interfere with... and in particular that won't interfere with non-target species. This latter part I suspect will be where the bulk of the research time is absorbed before a 'product' is available to submit for licensing.

The saddest part will be if the ecos and antis jump all over it with their doom stories of franken-this and BigAg-that and end up derailing what could be a very fruitful line of research

 

[domino]

The saddest part will be if the ecos and antis jump all over it with their doom stories of franken-this and BigAg-that and end up derailing what could be a very fruitful line of research

I don't think it will happen with the RNAi research because it's one of the primary areas of promise in cancer research.

The anti-science squad may do okay pretending GMOs are being used to destroy the environment but they always look a bit daft when they try and argue with medical researchers.

 

[mbc]

I don't think it will happen with the RNAi research because it's one of the primary areas of promise in cancer research.

The anti-science squad may do okay pretending GMOs are being used to destroy the environment but they always look a bit daft when they try and argue with medical researchers.

I think the anti-progress squad are standing on firm ground if this RNAi technology is going to require enslaving vast armies of mini inoculators, I expect the wee folk will be tamping with the work load

 

[pargyle]

I don't think it will happen with the RNAi research because it's one of the primary areas of promise in cancer research.

The anti-science squad may do okay pretending GMOs are being used to destroy the environment but they always look a bit daft when they try and argue with medical researchers.

I have no problem with GM research ... the issue I always have is that products tend to be rushed to the market without a sufficiently long term study to prove that they are not going to do untold damage to other elements of the environment. Whether the pro-GM lobby like it or not the investment in this type of research is so costly that there is a massive pressure on the scientists to push new products through to production at the earliest opportunity in order that the cost of the research can be recouped (and future profits secured).

Sadly, this is a phenomena that has been seen many times in the past within the pharmaceutical industry - I'm old enough to remember the effects of Thalidomide in many of my peer group ...

We are at an exciting juncture in the development of GMO's but it would be a tragedy if the promise that they provide was marred by commercial interests forcing them to the mass market too early, potentially without sufficient testing.

This research is very exciting and if it can be made to work safely the possibilities in other areas are endless .. Malaria as a result of Mosquitoes and sleeping sickness spread by the Tsetse fly immediately spring to mind.

 

[greengumbo]

I have no problem with GM research ... the issue I always have is that products tend to be rushed to the market without a sufficiently long term study to prove that they are not going to do untold damage to other elements of the environment. Whether the pro-GM lobby like it or not the investment in this type of research is so costly that there is a massive pressure on the scientists to push new products through to production at the earliest opportunity in order that the cost of the research can be recouped (and future profits secured).

Sadly, this is a phenomena that has been seen many times in the past within the pharmaceutical industry - I'm old enough to remember the effects of Thalidomide in many of my peer group ...

We are at an exciting juncture in the development of GMO's but it would be a tragedy if the promise that they provide was marred by commercial interests forcing them to the mass market too early, potentially without sufficient testing.

This research is very exciting and if it can be made to work safely the possibilities in other areas are endless .. Malaria as a result of Mosquitoes and sleeping sickness spread by the Tsetse fly immediately spring to mind.

This is not GMO though. It is work on RNA not genomic DNA so there is no permanent flow from one generation to the next and it won't linger in the environment as RNA is very unstable. In fact this group show that in the feed they give to the bees that the RNA is broken down completely in 3 days so no honey contamination either !

The issue of making enough of the stuff is a slight problem but there are ways to manufacture dsRNA in big enough quantities. They are even testing this same technology to target disease in vast shrimp farms in the far east and you would need huge amounts for that. Amounts that they seem to find economical.

As with all these things it is still going to be about IPM when it comes to Varroa but this opens up a treatment that they cannot build resistance to and that can be altered easily if better targets are found.

 

[pargyle]

Well ... as a layperson I'm now better informed and thank you. I'm gratified that this line of research could to be the answer to a lot of problems ... I can live with this science as it looks as though it is non-invasive, bio-degradeable, not contaminating and appears to have no lasting genetic effect on the host species - it meets my criteria ... Now wouldn't it be nice if we could have a pill the same to kill cancer cells ?

 

[Skyhook]

Well ... as a layperson I'm now better informed and thank you.

Very helpful post.

 

[PBee]

I'm a layperson also but....

Why would anyone want gene silencers to combat varroa when we already have generic, safe and cheap organic acids etc.?

Although plant based there is a lot of controversy around GM wheat in NZ/Australia at the moment and it uses RNA technology.

http://Evaluation of risks from creation of novel RNA

dsRNAs are remarkably stable in the environment. Insects and worms that feed on plants that make dsRNA can take in the dsRNA through their digestive system, where it remains intact (Gordon and Waterhouse, 2007, Mao et al., 2007).
Worms can absorb dsRNA through their skin when dsRNA is suspended in liquid(Cogoni and Macino, 2000, Tabara et al., 1998). Once taken up, the dsRNA can circulate throughout the body and alter gene expression in the animal (Mello and Conte Jr., 2004). In some cases, the dsRNA taken up is further amplified or causes a secondary reaction that leads to more and different dsRNAs (“secondary” dsRNAs) with unpredictable targets (Baum et al., 2007, Gordon and Waterhouse 2007

 

[Michael Palmer]

Well, I find the research exciting. One of my long time bee buddies is doing much of the field work with the project. He's coming by tomorrow for a visit. Thanksgiving holiday. It will be good to see bim again. We think so alike when it comes to bees, it's scary. A couple pints and talk about old times. I'll ask him what he's seeing, and if allowed, I'll post something here.

 

[Beefriendly]

"This cross-species, reciprocal exchange of dsRNA between bee and Varroa engendered targeted gene silencing in the latter, and resulted in an over 60% decrease in the mite population".
Similar approach as was discussed in the RNAi thread. Their 60% is better than good.
Hope for feeding and killing yet!