Wednesday, February 18, 2009

males and females but no sex! weird ants:

Wasmannia auropunctata, the little fire ant. native to the new world tropics but a very invasive pest worldwide does sex REALLY WEIRD:

Fournier, D., A. Estoup, R. M. Orivel, J. Foucaud, H. Jourdan, J. Le Breton, and L. Keller. 2005. Clonal reproduction by males and females in the little fire ant. Nature 435:1230-1234:

"discovered that W. auropunctata has remarkable and peculiar reproductive biology. Their abstract is as follows:

Sexual reproduction can lead to major conflicts between sexes and within genomes. Here we report an extreme case ...

We found that sterile workers are produced by normal sexual reproduction, whereas daughter queens are invariably clonally produced.
[i don't know if this means clones of queen's diploid somatic cell, or produced from an unfertilized haploid egg, which is produced by meiosis and therefore not a strict clone of the queen mother, will have to investigate]

some pics here, more explanation to come soon in new entry:

either way the offspring are effectively clones


In an apparent response to this conflict between sexes, genetic analyses reveal that males reproduce clonally, most likely by eliminating the maternal half of the genome in diploid eggs. [!!!] As a result, all sons have nuclear genomes identical to those of their father.

The obligate clonal production of males and queens from individuals of the same sex effectively results in a complete separation of the male and female gene pools...."

In summary: queens give rise to fertile queens by cloning. males mate with queens and give rise to

1) sterile diploid workers

2) males with only the males genes which effectively means they are clones of the males. wait! in most ants males are haploid and all their sperm are clones of their somatic cells. i'm gonna have to find more info. are auropunctata males haploid or dipoid?

roughly then males clone males of themselves and females clone females of themselves. the only time 'sex' (fertilization) results in offspring, those offspring are sterile..



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