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What did you learn from surfing FlyBase? Why do the inversions in Balancer chromosomes greatly reduce the frequency of crossing over in meiosis?. Autonomous vs non autonomous. Nonautonomous. Domineering - mutant cells disrupt the development of neighboring wild type cells.
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What did you learn from surfing FlyBase? • Why do the inversions in Balancer chromosomes greatly reduce the frequency of crossing over in meiosis?
Nonautonomous • Domineering - mutant cells disrupt the development of neighboring wild type cells. • Submissive - wild type neighbors rescue mutant cells.
RNAi in flies ds RNA in cultured cells. http://flyrnai.org/RNAi_goals.html
RNAi in flies • Express a fold back RNA from a transgene. • This results in tissue/temporal specific gene knockdowns. • Collections of transgenic flies are available that contain transgenes to knockdown the expression of most fly genes.
Gene targeting • Until recently not available in flies. • One difficulty is that one cannot select for a targeted cell. • A technique has now been developed that has been shown to work on a number of genes.
Technique requires first getting a germ line transformant for the knock out construct. • The DNA for targeting is excised by the activity of the FLP/FRT site specific recombination system. • The excised circle is then cut by the induced expression of a very rare cutting RE. • High rate of homologous targeting.
In Vivo Imaging • A number of developmental stages/tissues provide opportunities for in vivo imaging.
Genetic Screens • Recessive lethal mutations
Flp/FRT • High efficiency of FLP/FRT clone induction has allowed new types of mutant screens.