Homeosis

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Homeosis is the transformation of one body part into another, arising from mutation in or misexpression of specific developmentally critical genes. It may be caused by mutations in Hox genes, found in animals, or others such as the MADS-box family in plants. Homeosis is a characteristic that has helped insects become as successful and diverse as they are.^[1]

Homeotic mutations work by changing segment identity during development. For example, the Ultrabithorax genotype gives a phenotype wherein metathoracic and first abdominal segments become mesothoracic segments.^[2] Another well-known example is Antennapedia: a loss-of-function allele causes legs to develop in the place of antennae.

In botany, Rolf Sattler has revised the concept of homeosis (replacement) by his emphasis of partial homeosis in addition to complete homeosis, which is commonly accepted ^[3].

[edit] References

1. ^ Lodish et al., 2003. Molecular Cell Biology, 5th Edition. W.H. Freeman and Company, New York.
2. ^ Nusslein-Volhard & Wieschaus, 1980. Mutations affecting segment number and polarity in Drosophila. Nature 287, pp. 795-801.
3. ^ Sattler, R. 1988. Homeosis in Plants. American Journal of Botany 75: 1606-1617