> Interestingly, and I must check on this, somebody here in our bee lab
> told me that they think the young hatched cape bee lays fertilized
> eggs until she mates, after which she is able to lay both
> unfertilized and fertilized eggs.

I think there is a terminology error in the above (confusing
fertilised / unfertilised for diploid/ haploid, which are not always
interchangeable terms in these species). However,  the
main jist of this message, and the interest it conveys, is of course
correct.

 Thus in general, in many cases the virgin cape bee (A. m. capensis)
is parthenogenetic (thelytokous) and lays unfertilised eggs that
develop as matrilineal females because following egg formation (a
process of reductive meiosis where the diploid DNA content (two sets
of chromosomes) is duplicated and then seperated to form four haploid
copies) diploidy is restored in the egg pronucleus by terminal fusion
of two polecell nuclei (rather than between one egg pronuclei and the
sperm pronuclei following fertilisation (syngamy), as mentioned by
a previous posting.
Once she is mated, however, she displays largely, or entirely sexual
reproductive behaviour (arrhenotoky, where fertilised eggs are
diploid and develop as biparental females, unfertilised eggs are
haploid and develop as matlineal males... i have excluded the case of
diploid males here for simplicity). That is this thelytokous
parthenogenetic behaviour appears to change in that unfertilised
eggs largely, or entirley, fail to undergo terminal fusion, and thus
are haploid and develop as males, and fertilised eggs, (the majority
of her clutch at any point) which result from her usage of the
drone(s) sperm and are hence biparental diploid, develop as females.
Cheers
Rob
Robert Butcher,
Evolutionary and Ecological Entomology Unit,
Department of Biological Sciences,
Dundee University,
Dundee, DD1 4HN,
Tayside, Scotland,
UK.
Work Phone:- 01382-344291 (Office), 01382-344756 (Lab).
Fax:- 01382-344864
e-mail:- [log in to unmask]