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Dave Black

DocumentMore sex please.

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I think we talked briefly about this research in another thread.

 

I'm interested to see if this research leads to a suggested breeding programme using AI.

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I haven't the faintest idea why this should be a 'resource'.

It isn't.

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I haven't the faintest idea why this should be a 'resource'.

It isn't.

Hi Dave,

It was determined that the abstract and the document attached would be better served in the document library

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Do we know of any breed of bees which actually mate with more drones than the average number?

 

As far as I know Italian and Carniolans mate with around 15 to 20 drones.

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As far as I know Italian and Carniolans mate with around 15 to 20 drones.

This has been estimated in all sorts of ways, by measuring sperm volume or, most accurately, by determining paternity using DNA. Very broadly there appears to be a range, with some species (A.m.larmarckii) down at about five, and another (A.m.capensis) at thirty four. Mellifera (inc. ligustica and carnica) come in at 16.5-17.2.

I'm not sure this tells us anything. For the same bees, we kind of know that mating frequency depends on opportunity; isolation, wind, and temperature, that sort of thing. We don't know to what extent, if at all, it remains constant if you move the bees to a different mating environment.

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This has been estimated in all sorts of ways, by measuring sperm volume or, most accurately, by determining paternity using DNA. Very broadly there appears to be a range, with some species (A.m.larmarckii) down at about five, and another (A.m.capensis) at thirty four. Mellifera (inc. ligustica and carnica) come in at 16.5-17.2.

 

Was thinking if we can actually find out that one ecotype or a few lines of queens from certain breed of bees do actually mate with higher number of drones, then with some selection work and breeding we may be able to produce queens which will mate with higher than average number of drones in any weather condition. This could lead to a healthier bee population overall.

 

I guess this could be a bit harder to find out than most other things though especially to determine sperm volume (queen has to die I think) and to get DNA from the paternal side in a hive to find out how many drones the queen mated with. The queen may only use sperm from a few different drones at a time and progressively change into sperm from different drones during her life cycle.

 

Then you have to make sure that all the bees in the hive do come from that queen which maybe achievable if we are only collection young bees which have just hatched.

 

I think it will be a fantastic research topic for a research center to pursue.

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mmm, "we're British".

anyway, what a great heading for this thread..

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The queen may only use sperm from a few different drones at a time and progressively change into sperm from different drones during her life cycle.

There is no evidence that this is the case. Sperm use is effectively random and the only thing that matters is the volume 'submitted'. This kind of research is simple these days, but for me the take-home message is different. Rather than selective breeding the most effective thing we can do is to ensure the best mating conditions and drone availability. What we need is good management; more research is a waste of effort.

 

Michael Haberl, Diethard Tautz, (1998) Sperm usage in honey bees, Behavioral Ecology and Sociobiology, Volume 42, Issue 4, pp 247-255.

 

Pierre Francka, Michel Solignacb, Dominique Vautrinb, Jean-Marie Cornueta, Gudrun Koenigera, Nikolaus Koenigerc, (2002) Sperm competition and last-male precedence in the honeybee, Animal Behaviour, Volume 64, Issue 3, pp 503–509.

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Would it not be good to find out if we can actually select for lines of queens to actually mate with more drones which increases diversity in the colony there by improving general health of the colony? @Dave Black

 

Weather conditions might play a part in how well the queen is mated but if we can get queens which mate with more than average drones in good weather then that could be a bonus.

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Would it not be good to find out if we can actually select for lines of queens to actually mate with more drones...

In a world where we can not do all things, no I don't think so. Breeding for any quality is hard enough, particularly while trying to maintain a set of desirable traits. Selecting for more polyandrous queens has several problems, not least; we don't know what outcome we are looking for, what determines it, how we will measure it, and at what level of polyandry it will be found. We will expose the queens to more mating risk, both from predation, sexual disease transmission, and environment hazards, and we may make keeping desirable traits more difficult in a wider drone pool. The later is, after all, the reason we look for isolation in mating apiaries to start with. I as have said, I think the practical application of this information, if there is one, is to modify our management. If we are inseminating, we may use more drone fathers. If we are open mating, provide quality drone colonies, establish favourable mating apiaries, that sort of thing. We don't actually know what intensity of 'extreme polyandry' is actually achieved in particular mating apiaries and how (or why) that differs from the norm. That might be something we should look at.

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@Dave Black I'm finding this topic very interesting, thanks. Has anyone looked at it from the drones' perspective? Selecting for queens whose drone offspring produce more sperm per encounter? If on average each encounter transferred more sperm then the queen could achieve higher fertility with lower environmental risk.

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I have heard that AMM drones produce more Sperm per drone. I am not sure if that is a proven fact.

 

There is some research o suggest that Queens do select on which sperms to use at what time.

https://www.cals.ncsu.edu/entomology/apiculture/pdfs/DeGrandi-Hoffman_et.al.2003 copy.pdf

DeGrandi-Hoffman_et.al.2003 copy.pdf

DeGrandi-Hoffman_et.al.2003 copy.pdf

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Has anyone looked at it from the drones' perspective?

Yes, but again, we don't yet know how all this works. This is where it gets interesting. If we think about the male mate there can be different strategies in play. Drones could compete to mate, and to some extent they do, in that 'fitter' drones fly better, but there has not been any observation of competition between drones for a mating position in the comet, no suggestion of any sexual display, nor any of queen selection of drone. There is the possibility that drones respond to some cue (like lots of drones about) and increase copulation duration to transfer more sperm. It is also possible that there is some element of 'post-copulatory' selection, like sperm competition (using, for example, some form of selective metabolic support for stored sperm), or what's called 'Cryptic Female Choice' (CFC, which describes mechanisms like controlling oviposition behaviour). Part of this is because it is important that only one sperm fertilises an egg, so females have to have mechanisms to limit sperm access.

 

I think there are two basic strategies here. For one, we can imagine carefully selecting the right mate, maybe selecting another if that didn't work out, but generally investing a lot of time and resource by male and female in getting the best 'match'. Alternatively, we could avoid all that trouble and risk and mate once indiscriminately, but in order to be certain that we had a good chance of success put in place some mechanism for bet-hedging, like mate with lots of different males. Clearly, given the right circumstances both strategies work, and there appear to be strategies which combine elements of the dichotomy I've described.

 

Another important factor could be how sperm viability is maintained. Both male and female secretions create an environment where sperm can be stored for years, and 're-activated' on demand. It has been suggested seminal fluid was selected to increase insemination and paternity success whereas spermathecal fluid evolved to maximize sperm survival. In the various glandular secretions that accompany sperm so far 50 to 100 proteins have been identified that perform a wide variety of biological functions such as protection, energy generation, behaviour modification, and cell recognition. It is entirely possible that the production of amino acids, sugars, and minerals varies between individual males, and individual sperm do better in one (male or female) environment than another. While we know these are important in some organisms, my guess is they are less so in the polyandrous world of the honey bee where we are bet-hedging and not mate selecting, but I don't think anybody actually knows.

 

The evolution of polyandry is something worth being curious about, and the paper I've referenced below may help to give you some idea what it's all about.

 

Garcia-Gonzalez F, Yasui Y, Evans JP. 2015 Mating portfolios: bet-hedging, sexual selection and female multiple mating. Proc. R. Soc. B 282: 20141525. http://dx.doi.org/10.1098/rspb.2014.1525

 

 

There is some research o suggest that Queens do select

I have only had time to skim through this quickly on my phone. Of the five possible explanations for their results it wasn't clear to me which was the most likely or why, and inseminating using two drones made me wonder how robust the finding was. Nevertheless, I understand the suggestion, and I think I have discussed that above.

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