How CRISPR lets you edit DNA - Andrea M. Henle

Online deal days are back at Smith's. Don't miss your chance for extra savings when you shop, pick up, or delivery. You can save $30 on your first online order of $75 or more with your digital coupon. Plus, enjoy unlimited free delivery by starting a boost-free trial today. But hurry, these extra savings end October 20th. Restrictions apply. See site for details. Smith's, fresh for everyone.

Chronic migraine, 15 or more headache days a month, each lasting four hours or more, can make me feel like a spectator in my own life.

Botox Onabotulinum Toxin A prevents headaches in adults with chronic migraine. It's not for those with 14 or fewer headache days a month. It's the number one prescribed branded chronic migraine preventive treatment.

Rescription Botox is injected by your doctor. Effects of Botox may spread hours to weeks after injection, causing serious symptoms. Alert your doctor right away as difficulty swallowing, speaking, breathing, eye problems, or muscle weakness can be signs of a life-threatening condition. Patients with these conditions before injection are at highest risk. Side effects may include allergic reactions, neck and injection site pain, fatigue, and headache. Allergic reactions can include rash, welts, asthma symptoms, and dizziness. Don't receive Botox if there's a skin infection. Tell your doctor your medical history, muscle or nerve conditions, including ALS Lou Gehrig's disease, myasthenia gravis or Lambert-Eaton syndrome, and medications, including botulinum toxins, as these may increase the risk of serious side effects.

Why wait? Ask your doctor, visit BotoxChronicMigraine.com or call 1-800-44-BOTOX to learn more.

From the smallest single-celled organism to the largest creatures on Earth, every living thing is defined by its genes. The DNA contained in our genes acts like an instruction manual for our cells. Four building blocks called bases are strung together in precise sequences, which tell the cell how to behave and form the basis for our every trait. But with recent advancements in gene editing tools, scientists can change an organism's fundamental features in record time. They can engineer drought-resistant crops and create apples that don't brown. They might even prevent the spread of infectious outbreaks and develop cures for genetic diseases. CRISPR is the fastest, easiest, and cheapest of the gene editing tools responsible for this new wave of science. But where did this medical marvel come from? How does it work? And what can it do? Surprisingly, CRISPR is actually a natural process that's long functioned as a bacterial immune system. Originally found defending single-cell bacteria and archaea against invading viruses, naturally occurring CRISPR uses two main components. The first are short snippets of repetitive DNA sequences called Clustered Regularly Interspaced Short Palindromic Repeats, or simply CRISPRs. The second are Cas, or CRISPR-associated proteins, which chop up DNA like molecular scissors. When a virus invades a bacterium, Cas proteins cut out a segment of the viral DNA to stitch into the bacterium's CRISPR region, capturing a chemical snapshot of the infection. Those viral codes are then copied