Varroa tolerancy genes, y 2015

[Finman]

Phenotypic and Genetic Analyses of the Varroa Sensitive Hygienic Trait in Russian Honey Bee (Hymenoptera: Apidae) ColoniesAbstract


Varroa destructor continues to threaten colonies of European honey bees. General hygiene, and more specific Varroa Sensitive Hygiene (VSH), provide resistance towards the Varroa mite in a number of stocks. In this study, 32 Russian (RHB) and 14 Italian honey bee colonies were assessed for the VSH trait using two different assays. Firstly, colonies were assessed using the standard VSH behavioural assay of the change in infestation of a highly infested donor comb after a one-week exposure. Secondly, the same colonies were assessed using an “actual brood removal assay” that measured the removal of brood in a section created within the donor combs as a potential alternative measure of hygiene towards Varroa-infested brood. All colonies were then analysed for the recently discovered VSH quantitative trait locus (QTL) to determine whether the genetic mechanisms were similar across different stocks.

Based on the two assays, RHB colonies were consistently more hygienic toward Varroa-infested brood than Italian honey bee colonies. The actual number of brood cells removed in the defined section was negatively correlated with the Varroa infestations of the colonies (r2 = 0.25). Only two (percentages of brood removed and reproductive foundress Varroa) out of nine phenotypic parameters showed significant associations with genotype distributions. However, the allele associated with each parameter was the opposite of that determined by VSH mapping.

In this study, RHB colonies showed high levels of hygienic behaviour towards Varroa -infested brood. The genetic mechanisms are similar to those of the VSH stock, though the opposite allele associates in RHB, indicating a stable recombination event before the selection of the VSH stock. The measurement of brood removal is a simple, reliable alternative method of measuring hygienic behaviour towards Varroa mites, at least in RHB stock.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4409217/

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[For want of a better word]

It does not appear to be the scent of the mite itself that stimulates hygiene toward Varroa-infested brood [33]. Rather, hygienic bees preferentially detect and remove brood infested with DWV- transmitting mites, triggered by “deviant” volatile compounds released by the damaged infested pupae [34].

From the paper published in 2013...... a genetic anomolly ... a " gene controlled" trait that is missing or not expressed in Aml but prevalent in Amm ?

Perhaps a ghost " gene" of DWV hygienic behavior that was passed through to the "old" native honeybee sub species that survive in Northern Europe, and possibly had evolved a mechanism to defeat DWV.... that is missing in the Mediterranean sub species that evolved and were moved in by man later?

Yeghes da

 

[Finman]

that was passed through to the "old" native honeybee sub species

Remember that AMM is the youngest native bee race in Europe

 

[For want of a better word]

Remember that AMM is the youngest native bee race in Europe

Heads or tails... but Amm has evolved via different evolutionary lines...

Perhaps then the "OLD" Mediterranean sub types have lost the gene control ability to sniff out DWV infected grugs??

Yeghes da

 

[Beefriendly]

Heads or tails... but Amm has evolved via different evolutionary lines...

Perhaps then the "OLD" Mediterranean sub types have lost the gene control ability to sniff out DWV infected grugs??

Yeghes da

Perhaps the answer may lay in varroa having jumped specie from cerana. Non of the Apis mellifera strains have co-evolved with this particular parasite. Sensitivity to DWV infected larvae makes a sort of sense as they have co-evolved with this virus.
Of note varroa jacobsoni has recently jumped from A.cerano to A.mellifera.
https://phys.org/news/2016-11-species-varroa-mite-threatens-european.html

 

[Finman]

Heads or tails... but Amm has evolved via different evolutionary lines...

Perhaps then the "OLD" Mediterranean sub types have lost the gene control ability to sniff out DWV infected grugs??

Yeghes da

Amm is OK. It is best bee in the world.

It has biggest sting in the world

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[For want of a better word]

Amm is OK. It is best bee in the world.

It has biggest sting in the world

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Blimey.. will stick with me grugs and .. the still is doing fine!

Nos da