Hi tech searching of varroa resistant genes

[Finman]

https://academic.oup.com/jhered/art...e-Wide-Association-Study-of-a-Varroa-Specific

Varroa resistant hives were taken

When new workers emerged, 22 000 bees were marked with number
. They were set on varroa contaminated brood frame.


- With infrared camera they followed, which of workers really opened the brood caps.

Those bees were only 3.5% out of numbered 22000 bees, more or less.

"Of the 22 000 honey bees that were phenotyped during the behavior bioassays, 768 (3.49%) showed hygienic behavior against Varroa -infested brood cells. These included bees showing both low and high degrees of DUVB behavior. For the analysis, only the 122 top DUVB performing bees and 122 negative controls were used. ".

 

[Finman]

.
That is really interesting. You have mite resistant hives, but only 3,5% out of bees do really something in uncapping the sick brood.

When you pick larvae to graft new queens, how good change you have to find hygienic larvae into queen cells.


What I mean, not easy bee breeder...

.

 

[B+.]

Varroa resistant hives were taken

When new workers emerged, 22 000 bees were marked with number
. They were set on varroa contaminated brood frame.

More info on this (in Dutch) from last months BeeBreed NL meeting (http://beebreed.nl/koninginnenteeltdag-brascamp-2017.pdf)

 

[Fusion_power]

how good chance you have to find hygienic larva into queen cells.

The queen has to carry at least one copy and at least one drone the queen mates with has to carry the VSH genes. My experience is that about 90% of the queens I raise are highly resistant to varroa. This suggests that my bees are a bit more than 3.5% carriers of VSH traits. Grooming traits are the other side of this paradigm. The key trait I got from A.M.M. was strong grooming of mites off adult bees. I'm still waiting for one of the European programs put some effort into quantifying grooming.

 

[Finman]

.
Een project van LIB Hohen Neuendorf
Innovatiefonds Duitse Ministerie van Landbouw en
Voedselvoorziening.
Looptijd: april 2015 – maart 2018
Kosten: 1,3 miljoen Euro

A project LIB Hohen Neuendorf
Innovation Fund Federal Ministry of Agriculture and
Food.
Duration: April 2015 - March 2018
Cost: 1.3 million Euro

 

[wightbees]

I have not read links but from what I understand it's not one bee does all but a team effort I thought? For example, one be will open cell, another remove lava, another may clean and so on. Could someone correct me if wrong though?

 

[B+.]

Cost: 1.3 million Euro

....and, if you noticed on the penultimate slide in my attachment above, it is only useful within the breeding population (BeeBreed).

 

[Finman]

.
I do not know, what exactly costs, but to mark 20 000 with number costs something, and then you follow, what those bees do
.
And then map the geness of 122 bees.



Fusion is like a police dog Rex, which revieled all problems with nose.
.

 

[Finman]

I have not read links but from what I understand it's not one bee does all but a team effort I thought? ?

I did not find teamwork idea from the report.
.
There were different kind of working, but is does not mean teamwork.

 

[Beefriendly]

I have not read links but from what I understand it's not one bee does all but a team effort I thought? For example, one be will open cell, another remove lava, another may clean and so on. Could someone correct me if wrong though?

Rothenbuhler described AFB resistance due to single bees both uncapping and removing dead larvae. When he looked at the genetics and did some crosses he found that there was a recessive gene for each of the two actions and could produced hives where all bees uncapped but wouldn't remove and hives where the bees would only remove if someone else (him) did the uncapping of the diseased larva. He thought that in order to express the hygienic phenotype, an individual must be homozygous recessive at both the ‘uncapping’ and ‘removal’ loci. It has become a text book classic showing how genes can control behaviour. Although as time has progressed it's turning out to not be that simple.

 

[B+.]

one be will open cell, another remove lava, another may clean and so on. Could someone correct me if wrong though?

It is a complicated trait with some individuals expressing part of the trait and others doing the rest of the job. See the attachment to my post #3 above for more information.
Arista Bee Research in the Netherlands have a project which is looking for genetic markers for varroa resistance too (https://aristabeeresearch.org/program/). This is not suprising because some of the same people are on the scientific committee https://aristabeeresearch.org/about-us/

 

[Finman]

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More about these results

The most specific behavior is the detection of the Varroa parasitized brood cell through the cell caps. In an unselected population, less than 1% of the bees show this behavior.

An extremely left-skewed distribution appears, with many families whose members do not show the behavior at all and a very small number of families in which up to 2% of the members show the behavior.

If a bee initiates uncapping, she is usually supported by up to 10 other bees until the cell is completely uncapped. Some of these bees continue and begin removing impaired brood. Bees involved only in uncapping, without initiating this behavior, can be assumed to be less specific within this complex cooperation, as they are less able to detect the stimulus of a Varroa parasitized pupa through the closed cap.

Consequently, the whole hygienic process depends mainly upon the bees who first detect the parasitized brood and initially uncap the cells. This allows the other (presumably less sensitive) bees to more clearly recognize the stimulus of the parasitized brood through the partially opened cell cap and complete the hygienic removal of the handicapped brood.

We strongly assume that the bees which initiate the uncapping (detecting the infestation) are the most important ones for Varroa resistance breeding. Consequently, it is of major interest to know the genes involved in this special component of the resistance mechanism. Our specific bioassay allowed us to monitor the detection and uncapping of Varroa parasitized brood cells (DUVB) by individual bees.

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