Drosophila has always served as a genetic model system, which was used to understand various aspects of life.
This is largely due to some key aspects of fruit fly biology like its fast development cycle, ease and cheap to culture in the lab, wide array of genetic tool ( various mutants available, markers, presence of imaginal discs and balancer chromosomes, salivary gland chromosomes, or giant chromosomes, UAS – GAL4 system, P element for mutagenesis and transformation for generating transgenic fly, flp – frt system for generating somatic clones, UAS RNAi for gene Knockdown), fully sequenced genome of about 12 Drosophila species and now fully working CRISPR – CAS system to knock out genes completely
Discoveries in fruit flies have greatly contributed to our understanding in different aspects of biology.
It all began in famous Fly Room of Thomas Hunt Morgan at Columbia University in 1900 , where he and his student , especially , especially, A. H. Sturtevant, C. B. Bridges and H. J. Muller, had greatly extended the laws of Mendel.
They also were able to demonstrate that genes are carried on chromosomes and are the mechanical basis of heredity using Drosophila as a model organism.
During his distinguished career, Morgan wrote many books and published many scientific papers, as a result of his work, Drosophila became a force to reckon with in discovering many biological puzzles.
As mentioned earlier, the role of Morgan and his students was immense in making Drosophila, a powerful model system to understand genetics.
The legacy of great geneticists using Drosophila was continued by Edward B. Lewis, Eric Wieschaus ,Christine Nussllein Volhard and many others.
Advantages of Drosophila as model system
1) Short life cycle . It takes roughly 12 days @ 25°C.
2) Easy and cheap to grow.
3) Many genetic tools are available.
a) P-elements : used for Transgenic flies and generating mutants in genes, Over expression studies.
b) availability of large collections of deletions , inversions and duplications.
c) Balancer chromosomes.
d) UAS – GAL4 binary system of over expression of genes and also knocking down using RNAi lines.
e) FLP / FRT technique to create somatic and germline clones.
f) Easy to genetic studies because of availability many mutants, p element insertions, enhancer trap lines, protein traps lines and identifiable genetic markers.
g) Recombination occurs only in females and not in males.
h) Mobilization of p elements can be controlled.
4) Functional genomics (availability of genome sequences from 12 Drosophila species)
6) Imaginal discs
7) Good information exists about various genes involved during development of Drosophila at every stage of life cycle with well worked out mechanisms.
8) 70% of Human disease genes have counterparts or homologs in Drosophila. Hence results can be extrapolated to Humans.