Yet another puzzle

[Jimbo]

Hi Eric,

In reply to your question there is one gene the csd gene with many variations as you can see another gene fem gene is implicated

The isolation of the sex determination locus in honey bees led to the identification of the complementary sex determiner (csd) gene (Beye et al., 2003) (Figure 3A). The csd gene encodes a potential splicing factor that exists in at least 15 allelic variants that differ on average in ~3% of their amino acid residues (Hasselmann and Beye, 2004). The csd gene product is necessary for female development, because inactivation of csd gene product in female embryos causes a full switch into male development (Beye et al., 2003). The target of the csd gene product was recently identified as the feminizer (fem) gene (Hasselmann et al., 2008) (Figure 3A). The fem transcript is splicing differently in males and females, so that only female cells have a functional fem gene product. In males, splicing introduces a stop codon into the fem coding sequence.

Going back to Gavin's point. Three isolated colonies have been found in an isolated part of Scotland that were surveyed for black bees in 1993-94. by the Stoakleys The colonies were checked again this year and still found to contain pure black bees. How have three colonies managed to survive for about 16 years in isolation?

[Eric McArthur]

Hi Jimbo

Where are these bees located? Do they have Varroa?

Eric

[gavin]

Hi Jimbo

Where are these bees located? Do they have Varroa?

Eric

I suspect that the best answer to that one is to say - come to the November meeting and you'll find out from the person looking into them. If you can't we'll discuss it here afterwards.

[gavin]

A Gavinite?!! Come off it Eric ....

You could probably fairly easily model what will have happened at csd in these isolated colonies. I might even have a stab at it before the November meeting in Fife on bee breeding. Are you coming Eric?

[Jimbo]

Hi Eric,

Who mentioned Imidacloprid?

Time you had that holiday. Have a good one

Best wishes

Jimbo

[Stromnessbees]

Hi Jimbo

Three isolated colonies have been found in an isolated part of Scotland that were surveyed for black bees in 1993-94. by the Stoakleys The colonies were checked again this year and still found to contain pure black bees. How have three colonies managed to survive for about 16 years in isolation?

There might have been some drones flying in from further afield, but let's ignore that option for the moment.

These 3 colonies might have started with a very diverse set of genes, and with long-lived queens there might not have been enough generations yet to show the full effects of inbreeding.

According to Dorian, colonies with less than 75% brood viability (25% of larvae lost: 19% diploid males plus 6% other causes) will die out in winter, that is under regular management. Maybe these colonies were rather pampered by their beekeeper and just about managed to survive.

Of course, if they started as black bees and there was no other input, they will still be black bees now. The interesting thing would be to look at their brood pattern and count the number of empty cells within a randomly selected area (- count several and take an average if you like). Any more than 6% points to inbreeding.

Doris

[Rosie]

Hi Jimbo

Any more than 6% points to inbreeding.

Doris

I think I would be a bit cautious about that assumption. It might be true for new comb at the start of the year but it takes no account of pollen within the nest or hygienic behaviour, both of which seem to be additive during the season. There are also those new-fangled heater bees that recently hit the news.

Rosie

Thanks for an interesting talk, by the way, at BIBBA

[Stromnessbees]

Hi Rosie

Glad you enjoyed the talk. It's been a very long time since I have had to talk to an audience, especially as there were thousands of years of accumulated beekeeping experience in that room, very daunting for me with just a few.

The 6 % are quoted from Dorian's talk, and I suppose that we can allow for a few extra percent in adverse circumstances.

More figures I jotted down during the talk:

"If there are only 6 sex alleles present in the area the colonies are doomed."

"Aim to have at least 11 sex alleles in your local population."

"Only half of all colonies are effective drone producers."

"Within an area of 255 km2 (radius 9km) should be a minimum of 30 colonies to allow for enough genetic diversity, barriers like mountain ranges limit genetic exchange further."


Plenty there to discuss...
Doris

[Rosie]

Doris

I made a few notes from Dorian's talk too, but even he conceded that you had to be careful about counting the holes in the nest and the 6% allowance was based on another researcher's work who was probably working with exotic bees. He also said that the count only worked when the queen was introduced to a empty, drawn comb which needed to be counted 12 days after the introduction. If you wait too long to do the counting the queen may have returned to fill all the gaps.

Dorian's 30 colonies are also mentioned in Laidlaw and Page but but I think their figures and Dorian's were based on mathematical models. However, my interpretation of what Jacob Kahn had to say suggests that the bees are making choices that skew the results away from those predicted by statistical analysis. I don't know, however, whether the bees make things better or worse. Perhaps we should put our faith in Darwin and assume the bees have evolved to make good choices.

All the best

Rosie

[Stromnessbees]

Hi Rosie

... fair enough. I suppose the 6% apply to otherwise perfectly healthy colonies under ideal conditions, so allowances should be made. We just should not dismiss the idea of inbreeding problems alltogether.

Regarding the bees having evolved to make good choices: could Apiary Vicinity Mating, supposedly a trait of Amm, not be a possible Achilles' heel?

Doris