Left-handed folks aren't as rare as people with polydactyly or syndactyly (webbed hands or feet), but you may have noticed that there aren't as many left-handed people out there as right-handed people. Some of this is due to societal pressures, but I was intrigued to learn that much of it may have to do with genetics, and these genetic mechanisms may extend not just to which hand is dominant, but how the body plan is determined. Like many things in bioscience, it isn't always apparent that handedness and its genetic components are critical to other aspects of physiology, but as we will find out together, the genes associated with whether you use one hand more efficiently than the other can also influence developmental and neurological health!

In another life, I taught high school biology and had a lot of fun doing it. I had my students do the Cell City when we worked with organelles in the cell, and once we got to the genetics unit, we did something fun called Dragon Genetics. In this activity, students would pair up (one was the mommy dragon, the other the daddy dragon) and throw “chromosome” sticks to see what traits they would “pass on” to their theoretical dragon baby. The activity is quite simple once students understood basic Mendelian genetics (and some of the non-Mendelian patterns as well), and even my son was able to draw his own dragon baby when I had him be my guinea pig while he was still in elementary school. (Figure 1) There were some amazingly creative dragons adorning my classroom, and I hope you can share the Dragon Genetics activity with any teacher friends as we discuss non-Mendelian traits and disease here. As we celebrate the beautifully-designed experiments by Gregor Mendel that led to the modern study of genetics and genomics, we might also be reminded that patterns of inheritance, like many things in life, are far from binary.

Towards the end of my doctoral research, I first heard the rumblings of an acronym termed “CRISPR” that was starting to gather momentum. By the time I earned my doctorate, the applications that were discussed in both theory and in practice accelerated to the point that, while I didn’t fully understand the mechanism of the factors involved, I was certain that the discovery and re-engineering of this prokaryotic phenomenon would eventually be recognized with a Nobel Prize. Less than a decade after their first publications on the topic, ^{1, 2} Emmanuelle Charpentier and Jennifer Doudna were awarded the Nobel Prize in Chemistry “for the development of a method for genome editing,” which sounds a lot less important than it actually is!