Dosage compensation, the origin and the afterlife of sex chromosomes
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Over the past 100 years Drosophila has been developed into an outstanding model system for the study of evolutionary processes. A fascinating aspect of evolution is the differentiation of sex chromosomes. Organisms with highly differentiated sex chromosomes, such as the mammalian X and Y, must compensate for the imbalance in gene dosage that this creates. The need to adjust the expression of sex-linked genes is a potent force driving the rise of regulatory mechanisms that act on an entire chromosome. This review will contrast the process of dosage compensation in Drosophila with the divergent strategies adopted by other model organisms. While the machinery of sex chromosome compensation is different in each instance, all share the ability to direct chromatin modifications to an entire chromosome. This review will also explore the idea that chromosome-targeting systems are sometimes adapted for other purposes. This appears the likely source of a chromosome-wide targeting system displayed by the Drosophila fourth chromosome.
Key wordsdosage compensation Drosophila msl Pof sex chromosomes
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- Ashburner M, Golic KG, Hawley RS (2005) Drosophila, A Laboratory Handbook. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.Google Scholar
- Bull JJ (1983) Evolution of Sex Determining Mechanisms. Menlo Park, California: Benjamin/Cummings.Google Scholar
- Fung S-TC, Gowen JW (1960) Role of autosome-IV in Drosophila melanogaster sex balance. Genetics 45: 988–989.Google Scholar
- Hochman B (1976) The fourth chromosome of Drosophila melanogaster. In Ashburner M, Novitski E, eds, The Genetics and Biology of Drosophila. New York: Academic Press, pp. 903–928Google Scholar
- Lyman LM, Copps K, Rastelli L, Kelley RL, Kuroda MI (1997) Drosophila male-specific lethal protein: structure/function analysis and dependence on MSL1 for chromosome association. Genetics 146: 1743–1753.Google Scholar
- Muller HJ (1940) Bearings on the Drosophila work on systematics. In Huxley J, ed., The New Systematics. Oxford: Clarendon Press, pp. 185–268.Google Scholar