(I missed the original post since I am on the BestofBee list, and I
hope your replies to this mail seem important enough to Allen to
post them to BestofBee as well.)
I think I should comment on this as I am working with genetic analyses
in honey bees too. The following labs are involved in this kind of DNA
research in honey bees according to my knowledge (alphabetically):
A. Estoup (France; but he is no longer working on bees)
R.F.A. Moritz (Germany)
B.P. Oldroyd (Australia)
R.E. Page (USA)
(me, who used to work with R.Moritz, but am now a one person group)
In the following I will refer to publications by the persons (et al.)
mentioned above. Please e-mail me directly if you want the exact
citations.
> The research shows that in an open mated, mature queens
> colony:
>
> a) The workers, on average came from 10 different drones.
That is about right, but variation is quite large here, both between
subspecies in species, and between species:
average # of subfamilies
found in the sample +/- SD
Apis mellifera mellifera 11.5 +/- 0.7
carnica 13.0 +/- 8.5
ligustica 20 (1 colony only)
Apis andreniformis 13.5 +/- 4.5
dorsata 26.8 +/-10.8
florea 8.0 +/- 3.7
mellifera 13.8 +/- 5.5
These data were obtained by taking samples of about 20-200 worker bees.
The sampling error may be high in some cases. So, these data
have to be considered to be minimum estimates.
As the genetic analyses are relatively expensive regarding time and money,
only a few colonies have been investigated at all. There are more
data available by now that are in the process of publication.
Striking is the high number of subfamilies found in A.dorsata.
Correcting for sampling error it can be concluded that the queens of these
dorsata colonies have mated with up to 53 (!!) drones.
Drone density and weather are likely to be reasons for inbetween subspecies
variation.
> b) There are roughly equal numbers of workers from the 10 drones, so
> the queen not only stores the sperm but also uses it equally and
> randomly.
This needs not to be true. At least in most of the cases where worker samples
were sufficiently large, the number of workers from different drones
in the colonies investigated differed significantly. But I see no reason to
decide this question for all queens, i.e. to say ALL queens use the same
amount of sperm from each male, or ALL queens produce different numbers
of workers from each drone.
Two things are often mixed in this context: paternity frequency and
sperm usage. A queen can well fertilize the eggs in unequal paternity
proportions, but still use the sperm from her spermatheca at random.
And this seems to be true for most queens at least.
I have an article about sperm usage in BES coming up soon.
(I am always unsure about this copy-right thing, but I will
post the journals web-adress to the list.)
> c) Since each worker will have obtained a random half of the queen's
> chromosones all those which came from any of the 10 drones will be
> three quarters related to each other (all chromosones from the one
> drone are the same) and have three quarters of their characteristics
> alike; but on average they will only be one quarter related to the
> 90% of all other workers in the colony which came from a different
> drone parent. So the workers have an enormous amount of variation in
> their characteristics.
These statements were purely concluded from theory,
and have not anything particular to do with genetic analysis.
Characteristics are not genes! In fact, two workers of the
same subfamily will have more than three quarters of their
characteristics in common, because genes can have DNA sequences
that are subtle different but still produce the same protein.
> d) When a swarm occurred the workers did not divide randomly; they
> divided very much according to their drone parents, the swarm
> consisting very largely of workers from only three or four drones.
I would be curious to see the reference for this. I only know of
two investigations: Getz et al. (1982) performed experiments with
2 colonies headed by artificially inseminated queens (one cordovan,
one Italian drone):
Colony 1 group size cordovan normal
Swarm bees 25700 79 % 21 %
Remnants 11000 64 % 36 %
Colony 2 group size cordovan normal
Swarm bees 22500 58 % 42 %
Remnants 7800 43 % 57 %
There is a statistically significant difference in the composition
of swarm and hive bees in both colonies. However, there is
obviously no clearcut division of subfamilies.
Subsequent research suggested that cordovan workers just have a higher
tendency to swarm.
Kryger and Moritz (1997) used two colonies headed by naturally
mated queens (number of matings >= 21 and 24, respectively).
Their work was intended to investigate potential kin recognition,
i.e. worker's potential power to recognize the relatedness
towards offspring queens (the hypothesis being that workers of
the same subfamily as the young queen should preferentially join
the after-swarm). The authors found that the subfamily distribution in the
mother colonies before swarming was significantly different from the
subfamily frequencies in the primary swarm. They conclude that the
various subfamiles have different propensities for swarming. Furthermore,
they found different subfamily distributions between mother colonies
and after-swarms. However, again almost all subfamilies were present in
all 3 samples (mother colony, primary, after). They found no significant
difference between primary and after-swarms. They conclude that the effects
of kin recognition were less than 2 %.
____________________________________________________________________
Michael Haberl
Zoologisches Institut der Uni Muenchen Tel: ++49 89 5902-444
Luisenstr. 14 Fax: ++49 89 5902-450
80333 Muenchen e-mail: [log in to unmask]
Germany http://www.ebe-online.de/home/mhaberl/index.htm
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