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Gene Expression, Function, and Regulation. RS: Maribel Alvarez April 9, 2011. What do this characters have in common?. They are mutants. What is a mutant?.
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Gene Expression, Function, and Regulation • RS: Maribel Alvarez • April 9, 2011
What do this characters have in common? They are mutants
What is a mutant? An organism whose DNA has been changed. These changes cause the organism to display new characteristics or traits not found in wild-type. Wild-type (Typical form found in a population) Mutant
Scientist make mutant animals to study gene function and their products ~14,000 genes 50% found in humans ~40,000 genes Almost all genes are also found in humans ~19,000 genes 40% found in humans
Gene Expression x x How is the organism affected by the loss of this gene/protein? What role does the gene/protein have in the organism.
The development and growth of an organism is greatly dependent on the proper expression of genes
Human mutations results in medical conditions Sickle cell anemia: Hemoglobin Aniridia: Pax6 Primordial Dwarfism: PCNT Androgenic alopecia (baldness): Androgen receptor(AR)
How does an organism know when and where a gene is required to be on? How does your body know when to turn on Pax 6 to make your eyes? How does you body know only to turn on Pax 6 in cell located forehead and nose? Why don’t you develop eyes on your arm or legs?
Trancription factors are proteins that bind to regions of DNA to switch on genes in specific regions at a specific time. They regulate gene expression.
Organisms need genes expressed in specific cells at the right time. Gene expression must be regulated for proper growth and development of organisms
All cells have the same genetic information however only specific genes are turned on or expressed in each cell type
1. What would happen if the neuron specific gene is not expressed in cell one? 2. What would happen if the neuron specific gene was expressed instead of the epithelial specific gene in cell 2? Gene expression, function, and regulation No neuron 1. 2. The cell that was suppose to be an epithelial cell would be a neuronal cell.
Decapentaplegic(Dpp) is a TGF-β ligand (protein) important for wing growth and development in Drosophila Dpp expression wing disc Adult wing What do you think would happen to the wing if there is a mutation that would prevent Dpp expression (Can not be turned on)? What do you think would happen to the wing if Dpp is suddenly turned on in cells that usually do not express or need Dpp for wing development?
BMP4 is the human homolog of Dpp Fibrodysplasia ossificans progressiva is a disease due to high levels of BMP4.