Bee calamity clarified

[Sadsack]

Bee calamity clarified
Posted by Bob Grant
[Entry posted at 24th August 2009 08:45 PM GMT]

An illness that has been decimating US honeybees for more than three years probably isn't caused by a single virus, but by multiple viruses that wear down the bees' ability to produce proteins that can guard them against infection, according to a new study. Image: courtesy of Joseph Spencer

"We may not have the smoking gun," University of Illinois entomologist May Berenbaum, the study's main author, told The Scientist, but "we found the bullet hole."

Cells taken from bees that had succumbed to colony collapse disorder (CCD) were cluttered with ribosomal RNA fragments, suggesting that the bees had trouble translating genetic material into functional proteins, Berenbaum and her colleagues report today (August 24) in the Proceedings of the National Academy of Sciences.

"This is an elegant piece of work that weaves together data on host gene expression, microflora and observations of others into a coherent and compelling story," W. Ian Lipkin, a Columbia University researcher who was not involved with the study, wrote in an email to The Scientist.

Berenbaum and colleagues at the US Department of Agriculture screened thousands of transcripts in the guts of bees from both healthy and CCD-stricken colonies from the east and west coasts of the US.

CCD bees had several unusual RNA fragments resulting from broken, malfunctioning ribosomes. Multiple infections with a family of viruses called the picorna-like viruses, which seem to especially afflict CCD bees, could cause the appearance of such RNA fragments as they overwhelmed ribosomes and limited the cells' ability to manufacture functioning proteins. Bees that are not able to make proteins cannot mount effective responses to viral or bacterial infection or respond to dietary shortages, Berenbaum said.

Although the study didn't uncover a single cause for CCD, said Dan Weaver, a Texas-based apiculturist who was not involved with the research, it "provides some hints and suggestive evidence that maybe there's a general impairment of bees' ability to cope with pathogens at a basic regulatory step."

Berenbaum said that CCD may not be the result of one particular pathogen or environmental factor, but rather may occur when multiple viral infections overwhelm the bees' translational machinery. Bees may be able to handle one or two viral infections simultaneously, but not three or four. "You can recover from a gunshot wound," Berenbaum said, "unless someone is kicking you in the head at the same time."

While apiculturists like Weaver would rather have a single pathogenic cause of CCD in hand, the disorder, which has caused widespread bee mortalities in the US since 2006, appears to be more complex than that. "It would be better if we had more definitive evidence of what exactly is going on," Weaver said. "I think that would be everyone's fervent hope. But so far that hasn't materialized."

Berenbaum's study does, however, rule out some of the previously suggested theories for the cause of CCD. For example, the screen failed to turn up elevated expression of pesticide response genes in CCD bees. "The pattern we saw was inconsistent with pesticides as a cause," said Berenbaum, adding that this will probably not stop some in the honeybee business from blaming pesticide manufacturers for the disorder. Interestingly, the screen also failed to find increased expression of immune response genes, suggesting that the bees were not able to mount effective responses to the pathogens attacking their colonies.

In addition to the ribosomal RNA fragments, Berenbaum's screen revealed a suite of other transcripts, at least one of which resulted from viral infection, which corresponded to CCD. Berenbaum said that she hopes researchers can use these characteristic transcripts and ribosomal RNA fragments to develop a way to rapidly identify bees struck with CCD. "At the very least we have markers that we think is a reliable and objective indicator of CCD," she said. "Ultimately we can have a quick assay that would allow a more objective analysis of CCD."

Weaver welcomed the idea, but lamented the pace at which scientists are able to fully understand CCD. "I'm happy that we're making progress," he said. "It's just painfully slow."

[faithinacure]

SS: Thanks for your post. Here's another in the news today:

New Clue in Disappearing Honey bees
___
WASHINGTON — Researchers have a new clue to the collapse of honey bee colonies across the country — damage to the bees' internal "factories" that produce proteins. Theories about the cause of bee colony collapse have included viruses, mites, pesticides and fungi.

The new study of sick bees disclosed fragments of ribosomal RNA in their gut, an indication of damage to the ribosomes, which make proteins necessary for life, according to a study in Tuesday's issue of Proceedings of the National Academy of Sciences.

RNA, which is made from DNA, is central to protein production.

The sick bees suffered an unusually high number of infections with viruses that attack the ribosome, the researchers from the University of Illinois at Urbana-Champaign and the U.S. Department of Agriculture reported.

"If your ribosome is compromised, then you can't respond to pesticides, you can't respond to fungal infections or bacteria or inadequate nutrition because the ribosome is central to the survival of any organism. You need proteins to survive," May R. Berenbaum, head of the department of entomology at Illinois, said in a statement.

The researchers said the varroa mite, which was accidentally introduced to the U.S. in 1986, is a carrier of picorna-like viruses that damage the ribosomes.

The mite may act as a tipping factor leading to ribosome breakdown, the researchers said.

The study was funded by the Department of Agriculture.___

[Katinka]

SS, Faith, thank you for this interesting post! I got a little curious and thought that there might be a connection to our disease so I looked up that Picornavirus..

Picornavirus - Wikipedia, the free encyclopedia

Picornaviruses are separated into nine distinct genera and include many important pathogens of humans and animals. The diseases they cause are varied, ranging from acute "common-cold"-like illnesses, to poliomyelitis, to chronic infections in livestock. Two main categories are enteroviruses and rhinoviruse.

Could the cause be a mutated virus strain? I'm thinking: is there a relationship between our disease, new emerging diseases in animals and in plants/trees such as 'sudden oak death'?

Is something happening in nature? A fatal virus, transmitted over insects
that are part of M? YES, I think so! The Baculovirus and the CaMV which are both used in bio-insecticides are IMO highly suspect.

Kat

[Sadsack]

Kat -

That there might be a connection between M and bee deaths was one of the first things I thought of when I realized that bee products (pollen, propolis, manuka) are helpful with this condition.

I had that thought very early in my sickness, and I am hesitant to admit this, but my thoughts were that "M" was trying to kill the bees because they could help us. Oh, I attributed an awful lot of "intelligence" to M, not to mention EVIL.

I don't think that way anymore, but I have not dismissed the "evil intelligence" possibility.

I also wonder if M is involved in the bat die off. Both of these mass deaths spell ecological disaster for us.

SS

[Katinka]

Originally Posted by Sadsack

I also wonder if M is involved in the bat die off. Both of these mass deaths spell ecological disaster for us.

SS

SS, I think so..something in nature is happening..and it doesn't look good..

If the bats die..there will be many, many more insects and WE all know what that means!

Kat

[Sadsack]

Kat -

Exactly what I was thinking. Each bat eats half its weight in insects daily. The only insects that won't increase are the ones we need to cross pollinate our crops for food - bees.

Well, Kat - just enjoy as much as you can while you can. We can try to figure things out, but I think things are happening way too fast to stop them.

SS

[Kritters]

Originally Posted by Sadsack

Kat -

Exactly what I was thinking. Each bat eats half its weight in insects daily. The only insects that won't increase are the ones we need to cross pollinate our crops for food - bees.

Well, Kat - just enjoy as much as you can while you can. We can try to figure things out, but I think things are happening way too fast to stop them.

SS

Sadly...I'm afraid it's true, SS...

[Katinka]

Originally Posted by Sadsack

Well, Kat - just enjoy as much as you can while you can. We can try to figure things out, but I think things are happening way too fast to stop them.

SS

Yes, SS, you are right! We all should try to enjoy our lives the best we can..I know this isn't always easy with this disease but I try to see the wonderful things in life..my children, my friends..and that makes me feel better..

....and the strong belief that there will be HELP soon! For all of us!!

Kat