The insect caspases.

Developmental and tissue homeostasis is a delicate balance between cell proliferation and cell death. The activation of caspases, a conserved family of cysteine proteases, is a main event in the initiation and execution of programmed cell death. While caspases have been characterized from many organisms, comparatively little is known about insect caspases. In Drosophila melanogaster, seven caspases have been characterized; three initiators and four effectors. In mosquitoes, several putative caspases have been identified in the genomes of Aedes aegypti and Anopheles gambiae. A small number of caspases have been identified in the Lepidoptera, the flour beetle, Tribolium castaneum, and the pea aphid, Acyrthosiphon pisum. The availability of new insect genome sequences will provide a unique opportunity to examine the caspase family across an evolutionarily diverse phylum and will provide valuable insights into their function and regulation.