19.1.11: Drosophila Melanogaster
- Page ID
- 5959
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Some of the reasons for its popularity:
- The flies are small and easily reared in the laboratory.
- They have a short life cycle The figure shows the various stages of the life cycle (not all drawn to the same scale). A new generation of adult flies can be produced every two weeks.
- They are fecund; a female may lay hundreds of fertilized eggs during her brief life span. The resulting large populations make statistical analysis easy and reliable.
- The giant ("polytene") chromosomes in the salivary (and other) glands of the mature larvae.
- These chromosomes show far more structural detail than do normal chromosomes
- They are present during interphase when chromosomes are normally invisible.
- More recently, Drosophila has proven in other ways to have been a happy choice.
- Its embryo grows outside the body and can easily be studied at every stage of development.
- The blastoderm stage of the embryo is a syncytium (thousands of nuclei unconfined by cells) so that, for example, macromolecules like DNA injected into the embryo have easy access to all the nuclei.
- The genome is relatively small for an animal (less than a tenth that of humans and mice).
- Mutations can targeted to specific genes.