Chromosome Function: Sex Differences


The distinct development of females and males is usually the consequence of differences in their sex chromosome constitution. To compensate for these differences, the sexes adjust the expression of sex‐linked genes. Some inheritance patterns depend on the sex or sex chromosome make‐up of a parent.

Keywords: sex chromosomes (X, Y, Z, W); sex determination; dosage compensation; female/male; sex‐based inheritance patterns

Figure 1.

Summary of the sex‐determining mechanisms of humans, flies and worms as described in the text. Some details have been deleted for simplicity, including the autoregulation of Sxl expression that maintains it in the mode set by the X:A ratio, the DAX1/SRY interaction, and some of the genes in the regulatory cascades.

Figure 2.

Summary of some solutions to the ‘gene dosage problem’, as described in the text. (a) X‐inactivation control in mammals, simplified for clarity by not showing that initially both X‐chromosomes accumulate XistRNA. The X‐chromosome drawn in green has been inactivated, except for its Xist locus and its pseudoautosomal region. (b) Summary of the situation in flies (the DCC complex is shown schematically as a clump of circles) and nematodes (the chromosome binding complex is shown schematically as a clump of diamonds). As in Figure , autoregulation of Sxl is not shown.



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This article was reviewed by the authors in 2013 who suggested the following eLS articles for updates to this material:

Mammalian Sex Determination

SRY, Sex Determination and Gonadal Differentiation

Sex Chromosomes

X‐chromosome Inactivation and Disease

Dosage Compensation Mechanisms: Evolution

Y‐chromosome‐linked Traits

Mammalian Sex Chromosome Evolution

Evolution and Organization of Monotreme Sex Chromosomes

Evolution of the Mammalian X Chromosome

Sex Chromosome Abnormalities

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Mueller, Jacob L, and Wolfner, Mariana F(Sep 2005) Chromosome Function: Sex Differences. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0003939]