The central dogma is one of the many fundamental concepts all teenagers in high school are encouraged to learn. It states that the information to make proteins is encoded by DNA and this information is relayed by an intermediate molecule called RNA. Harold Marin, a local high school and junior college graduate that now works at UCSF, enlightened us on the current state of affairs with DNA technology. He began by showing glowing bunnies that had been genetically engineered- Now, how can that be real? For those that did not know - genetic modification is not only done to food, but also to other organisms - case in point- these bunnies! Scientists now have the molecular tools to cut and paste specific gene sequences from one organism to another. With the bunnies, a pGLO plasmid (from a fluorescent jellyfish) is used to genetically modify them to glow. As described by Mr. Marin, CRISPR technology involves an RNA guide and Cas9, which is a protein that acts like scissors to modify gene sequences. He explained that the CRISPR project began when scientists found repeating codes in bacterial DNA. After studying these sequences they realized that it matched the codes of bacterial viruses called bacteriophages. They called these repeating codes of DNA CRISPR (for Clustered Regularly Interspaced Short Palindromic Repeats). They also found that these DNA codes associated with scissor-like proteins in the bacteria which they called Cas (for CRISPR-Associated proteins). Now why would bacteria carry virus DNA? The answer is that during a viral infection, the bacteria uses the CRISPR to recognize the foreign material and “cut” it out. This is an example of a very rudimentary bacterial immune system. By manipulating the properties of the Cas9 protein, scientists were able to apply it to other areas of biological research. When CRISPR and Cas9 work together they can scan and break the double stranded DNA, which then opens the door to insert a new DNA code within this break. As the cell repairs the broken strand, it will read the new code as its own and make that new protein that was inserted. After Harold explained the basic function of this technology he went on to discuss the work he does- which involves putting the CRISPR guide into human cells with Cas9 in order to “cut out” their genes one-by-one and compare to a control group. However, the work he does can go beyond gene editing on a cellular level. With this technology, scientists have been successful in manipulating genes in human embryos. Due to ethical issues, however, the embryos are not allowed to develop beyond day 14. Cas9 can also be reengineered to repress or activate it gene expression. In the world of genetics, Cas9 is one protein out of many. One of the questions brought up during the after cafe focused on the ethics involved when using this technology?. As teenagers it is our job to know how this science is applied because it will continue to be part of our future. Mr. Marin signed off with a challenge for the next generation to understand, apply and appreciate this new technology and to avoid creating a society such as that seen in the movie GATTACA.
Submitted by Lindsey Tah Piner High STEAM club president