Sex and the Hierarchy

I should like to make it very clear that the schematics of the sex determination hierarchy shown below are by no means comprehensive. In the interests of simplicity and brevity, I have neglected to mention numerous genes that also play integral and interesting roles in the hierarchy: e.g. genes that actually function as numerator and denominator elements in determining the X-chromosome:autosome ratio, genes that function in the mother, but when defective, can affect the sex of the progeny, and the whole series of genes involved in germline sex determination.

Download this figure to view the sex determination hierarchy


Attempting to cite all the publications that have gone into creating this hierarchy would take up far too much space. I have opted instead to cite the following reviews. For the interested reader, these should serve as a good introduction:

Baker, B. S. and Belote, J. M.
Sex determination and dosage compensation in Drosophila melanogaster. Annual Review of Genetics 1983, 17: 345-93.

Burtis, K. C.
The regulation of sex determination and sexually dimorphic differentiation in Drosophila. Current Opinion in Cell Biology 1993, 5:1006-14.

Cline, T. W.
The Drosophila sex determination signal: how do flies count to two? Trends in Genetics 1993, 9:385-90.

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Revised: July 9, 2005