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Thread: Yet another puzzle

  1. #21
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    Hi Eric,

    To answer your first point would 40 years working in scientific research in a Scottish University rated as one of the top 50 Universities in the World in one of the largest research institutes within the University that was rated 5* in the last RAE excercise a few years ago as one of the top institues in the world for the quality of our research be enough science for you?
    Back to inbreeding I went for a second opinion today and asked one of our top genetic professors who's speciality is human population genetics. He did not use a bowl of fruit example but said if you have a large bag of hundreds and thousands of all diffrent colours (he admits to having a sweet tooth) and you take out a handful you will still have at least one of every colour. The probability of picking out all the red ones in the first handful is very remote therefore you will still maintain your genetic diversity. If you relate this to the bee with so many CSD alleles the probability of you getting inbreeding is remote. You could still get inbreeding if you were very unlucky and managed to picked out all the same allele but the probability of this was extremely remote.
    I agree with Gavin in point 3 above that inbreeding is a bit over-hyped but beekeepers should be aware of the potential. I also think that there may be other factors involved. I was reading a research thesis today about the effects varroa treatments have on sperm numbers in drones and viability in the queen. To me that is more scary than potential inbreeding

  2. #22

    Default Yet Another Puzzle

    Hi Gavin

    Item 1 Re bowls of fruit! What implications are you talkng about? Are you coming to burn my house down?

    Item 2 Hit a nerve there - They should be informing me of this! Not you! Pleased to hear that they have oodles of commonsense - whatever that means!

    Item 3 Good to hear that you also consider inbreeding an issue, "important" would have been good!
    What does overhyped mean? - When beekeepers are still breeding from their best colonies instead of all of their colonies in a scenario of constant colony loss "hype" is not the key word - "education" on the dangers of breeding from the few would be more relevant

    Item 4 The Holy Grail of csd is stifled by chronic, related colony interbreeding - even Jon agrees with this postulation and I quote "I have argue elsewhere on the basis of this paper that you have to be caeful with reducing numbers of colonies...." .
    Inbreeding is already a problem around Crinan and was in the Clydebank area until the Clyde Area Bee Breeder Group introduced new blood into the Clydebank, Hargate and Cochno areas of West Dunbartonshire this year. New colonies created this year were established in the areas mentioned where no honey bees had been seen for some 6 years.

    Item 5 "It is a a good point that beekeepers see hygenic behaviour and confuse it with diploid drone gap". Get away wi ye! Treating against Varroa, especially with formic acid, would lay that particular ghost once and for all.

    Item 6 Gavin, Gavin - Is there no hope for you? Over time when the reducing gene pool reaches critical mass as the random drones continue to meet their sisters, cousins and aunts in the love match, the colonies will initially exhibit loss of vitality and then just go into melt down. I have, as I have stated elsewhere been closely involved in such a real life scenario involving inbred colonies on Islay in the 70s - probably before you were even a twinkle in you dad's eye!
    Unfortunately I go on holiday tomorrow - so I will have to take a rain check on further intercourse with this engrosssing discussion

    Regards

    Eric
    Eric

  3. #23
    Senior Member Jon's Avatar
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    Quote Originally Posted by Eric McArthur View Post

    Item 3
    What does overhyped mean? - When beekeepers are still breeding from their best colonies instead of all of their colonies in a scenario of constant colony loss "hype" is not the key word - "education" on the dangers of breeding from the few would be more relevant
    Eric
    Eric
    Breeding from your best colony is not a problem when the drones in the general population local to it carry all or most of the csd alleles. (adopting italic convention)
    You would need to demonstrate that the local drone population carries less than 6 csd alleles before suggesting that this strategy would lead to an inbreeding problem.

  4. #24

    Default Yert another puzzle

    Hi Jimbo
    I am impressed but not overwhelmed! Your prof, by your own admission used hundreds of thousands
    of genes (coloured sweets!!) in his response to your question. In my postulation we are not dealing with hundreds of thousands of genes - we are dealing with - how many? You tell me! As I stated in my response to Gavin - I have witnessed massive inbreeding and colony collapse due to loss of genetic diversity caused by reducing colony numbers over time, (and not cosmic time!).
    Your concurrence with Gavin puts you at odds with Jon, who rightly recognises that inbreeding can be an issue.
    In the present scenario there are areas in Scotland which are either in a borderline situationn with inbreeding or are already suffering the effects. Most thinking, educated (in beekeeping !) beekeepers
    are now aware that inbreeding is a problem waiting in the wings to manifest itself into a major problem as unrelated colony numbers continue to decrease.
    Your input regarding anti Varroa chemotherapy is another topic I would be delighted to get embroiled in. But I go on holiday tomorrow - too bad!

    Regards

    Eric

  5. #25
    Senior Member Jon's Avatar
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    Hi Eric:

    Your concurrence with Gavin puts you at odds with Jon, who rightly recognises that inbreeding can be an issue.
    Just to clarify, I think everyone recognises that inbreeding is 'an issue' but only in very specific situations where there is a demonstrable loss of alleles at the csd locus.
    Demonstrable being the operative word.

    Enjoy your holiday. I am sure there will still be vigorous and non-inbred colonies around when you get back!
    -not to mention vigorous debate!

  6. #26
    Administrator gavin's Avatar
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    Enjoy your holiday Eric, and no, if your house burns down while you are away, it wouldn't be me!

    Forget the fruit then. I thought that it was a clear way of seeing that halving the population size doesn't half the allelic diversity in it. It just seems like commonsense.

    Anyone in an isolated location who obtains one colony (quite common with beginners) will be at risk of having problems with inbreeding.

    In a good, diverse colony ...

    Queen: ab
    Sperm in her spermatheca: c, d, e, f, g, h, i, j, k, l, m, n (for example)

    Next generation, still one hive, still isolated, one example:

    Queen: bk
    Sperm: a, b (no other options)

    There are lots of other possibilities for the genotype of the queen, but the sperm in her spermatheca in this unusual case of total isolation can only be a or b.

    So inbreeding is a serious risk when the population size is very small and the apiary isolated. It is hardly a risk when you have 10 well-mixed and diverse colonies dropping to 5, then doubling. However that was what you wrote in your magazine articles, and it is rubbish.

    If I remember right Andrew Abrahams has his closed population which was based on 6 stocks sourced from several areas in Scotland with pure Amm. He built up the numbers, and inbreeding doesn't seem to be a problem for him.

    all the best

    Gavin

  7. #27

    Default Yet Another Puzzle

    Hi Jon

    I think we have met before! The Irish forum springs to mind!

    Regarding:
    "Breeding from your best colony is not a problem when the drones in the general population local to it carry all or most of the csd alleles. (adopting italic convention)
    You would need to demonstrate that the local drone population carries less than 6 csd alleles before suggesting that this strategy would lead to an inbreeding problem".

    Not when all the drones are from your own colonies and a limited number of nearby apiaries with only a couple of colonies, over time!!

    Regarding pepper pot phenomenon:

    To eliminate any factors clouding a suspected inbreeding situation where peppe-rpotting is a symptom:
    1 To eliminated any major Varroa presence where hygenic behaviour is manifest eliminate the mites with formic acid.

    2 To clear up any chalk brood manifestation - feed colony with around 2 - 4 litres of 1 (sugar) : 2 (water) sugar syrup- this will clear up chalk brood in around 2 weeks - no need to requeen!
    The floor board insert should always be in place to record such events in the colony - it will show chalk brood drop as well as mite drop! If the pepper potting does not disappear - the problem is inbreeding!

    I heard that the BBKA apiary lost all its bees recently - and imported replacements because they could not get bees locally.

    Jimbo I have no proof of identity - but I have a name in my mind! Gavin and I go a long way back and I don't really agree with much of what he says - right Gavin!! I believe the feeling is mutual but I lose no sleep over it.
    Your conclusions on imidacloprid, I would dispute and opinions are formed primarily in the peer group to which one subscribes you being a Gavinite puts us pretty much on a collision course. But not to worry - history will declares a winner (and H. sapiens could be the loser!)

    "Getting back to inbreeding I (you) may be mistaken but I think you may be confusing a general reduction in genetic material with the specific inbreeding problem which can be caused by a reduced number of allees at the csd locus".

    Notwithstanding any bee population will ultimatedly collapse when all the colonies are too closely related - in a closed population scenario - the which I have had personal experience with in th epast.

    Regards

    Eric

  8. #28
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    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?

  9. #29

    Default Yet Another Puzzle

    Hi Jimbo

    Where are these bees located? Do they have Varroa?

    Eric

  10. #30
    Administrator gavin's Avatar
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    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?

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