Day 7: In Our DNA
by Chris Smith
April 25th is DNA day, but what first comes to mind when you hear DNA?
For some, perhaps it is a twisting, ladder “thing.” For others, it may be the evidence criminals leave behind in the latest crime show. Deoxyribonucleic Acid, or DNA, is one of many molecules in the body that makes you, well, you! A change in one section, or sequence, of that twisting ladder can have major changes in the body. Let’s explore some of these molecules and how advancements in science and technology have major impacts.
CRISPR
Through these advancements, scientists have the ability to change an organism’s DNA using tools called gene (or genome) editing. Clustered regularly interspaced short palindromic repeats, or CRISPR, is one such genome editing tool. CRISPR-Cas9 tool was adapted from a naturally occurring phenomenon bacteria use in immune defense. Using a small piece of ribonucleic acid (RNA) that binds to a targeted piece of DNA. An enzyme then “cuts” the targeted portion. Genetic material can then be added or deleted using the cell’s repair system. Or the DNA can be changed entirely by replacing a customized DNA sequence. While there are some ethical concerns surrounding gene editing, there is hope there is a role in possibly treating or preventing certain diseases.
Cheap DNA Sequencing
$2.7 billion – that is the cost of the first genome sequence as part of the Human Genome Project. Completed in 2003, it took 13 years and thousands of scientists. Today, with new technologies, we now have sequencing companies that can provide a human genome for $100 to $200. The ability to have cost-effective and efficient sequencing from a large group of individuals can have implications in diagnostic and disease therapies. Currently, sequencing detects and can provide physicians with targeted treatments such as some cancers.
Opto and Chemo Genetics
Optogenetics and chemogenetics are two different ways to modify neuronal activity. Both have the ability to do this with specific types and regions of neurons. Additionally, both neuromodulators employ the use of genetic strategies to either light-sensitive ion channels (opsins for optogenetics) or designer receptors exclusively activated by designer drugs (DREADDs for chemogenetics).
The optogenetic technique can be used to investigate neuron connections in different areas of the brain, the role of different areas of the brain regarding different behaviors, and different neurological disorders. However, this technique does require device implantation.
Chemogenetic uses local or systemic pharmacology that can increase or reduce neuronal activity for several hours. Additionally, it is non-invasive and reversible. Chemogenetics has advanced biomedical research in neurodegenerative and psychiatric conditions.