171 likes | 356 Vues
Rewriting the Genetic Code. By: Ishika Desai. Genetic Code. DNA is made up of long sequences of letters that code for specific amino acids. Codons are made up of three of these nucleotides ( ACTG) Most three letter combos code for amino acids, but some represent stop codons.
E N D
Rewriting the Genetic Code By: Ishika Desai
Genetic Code • DNA is made up of long sequences of letters that code for specific amino acids. • Codons are made up of three of these nucleotides (ACTG) • Most three letter combos code for amino acids, but some represent stop codons.
How does it work? • System overwrites specific DNA sequences within the genome • Uses Multiplex Automated Genome Engineering (MAGE) to site-specifically replace stop codons across E. Coli strains • Uses Conjugative Assembly Genome Engineering (CAGE) to precisely control a naturally occurring process that bacteria use to exchange genetic material
Potential Advances • Engineer bacteria that are resistant to several viruses • Build proteins not found in nature
Bibliography • Isaacs, Farren J., Harris H. Wang, and Peter A. Carr. "Precise Manipulation of Chromosomes in Vivo Enables Genome-Wide Codon Replacement." Science Magazine: Sign In. N.p., 15 July 2011. Web. 09 July 2013. <http://www.sciencemag.org/content/333/6040/348.full>. • Trafton, Anne. "Scientists Unveil Tools for Rewriting the Codeof Life." MIT's News Office. N.p., 15 July 2011. Web. 09 July 2013. <http://web.mit.edu/newsoffice/2011/editing-genome-0715.html>.
MedulloBLASToma By: Ishika Desai
Medulloblastoma • Malignant brain tumor located in the cerebellum • Makes up 20% of brain tumors in children • Cause of medulloblastoma is unknown • Can become cancerous if it is combined with the expression of the catenin beta 1 gene
β-catenin Gene • Officially known as CTNNB1 • Expression of β-catenin is associated with: • Carcinoma • Lung Cancer • Medulloblastoma • Malignant breast tumors • Endometrial cancer • Ovarian cancer
shRNA production within E. coli DNA shRNA-induced silencing complex Pol II Pre-miRNA Drosha shRNA lysteriolysin O Dicer enzyme Exportin 5 Leaves E. coli
≈≈≈ Invasin production CTNNB1 mRNA shRNA CANCEROUS CELL shRNA Genetically engineered E. coli
Methods currently used to treat cancerous medulloblastomas: • Surgery • Radiation • Chemotherapy • All of the methods listed above generally still result in a considerable amount of damage to healthy tissue • Oncologists and researchers have been looking into cancer treatments that precisely distinguish between healthy and diseased cells
Expected Results Inverter (NOT) Logic Gate A X
Expected Results • After invading the cancerous cells, it is expected that the shRNA in the RISC will bind to the CTNNB1 mRNA transcripts and induce mRNA cleavage • This will silence the CTNNB1 gene