Summer is rapidly approaching and I’m so looking forward to a nice long Memorial Day weekend with outdoor cookouts and plenty of time for gardening. Those of us New Englanders that have endured a long, hard winter really appreciate ending our hibernation and spending time outside in the spring and summer. Gardening is one of my favorite activities, and in this region we are strongly advised to wait until Memorial Day to do the majority of our planting. But after hearing that one of my colleagues had just come down with poison ivy, I began to wonder why these plants so often get in the way of enjoying our short season of outdoor life. Poison ivy, oak and sumac have always been a very annoying part of growing up in New England. They are plants that I never had too many fond thoughts of. Yet, I never really knew much at all about them – other than the itchy, irritating red rash they cause – that is. I decided to do a little digging, reasoning that they must have some redeeming, or at least interesting, biological qualities. After all, it seems that they are only protecting themselves against all of us herbivores. They can’t exactly run away from us, so they have to keep us at bay some how. Their defense mechanism seems quite clever actually.
A quick check in Wikipedia revealed that poison ivy is a member of the Anacardiaceae family of flowering plants. To my surprise cashew and pistachio plants are also members of this same family. Apparently not all members of this plant family are skin irritants at least! The reaction you get from poison ivy is due to contact with urushiol, a very potent oil found in the sap. In fact, only about 1 nanogram is needed to cause a rash (as little as ¼ of an ounce is said to be necessary to cause a rash on every person on earth). The rash, or Toxicodendron dermatitis, is a result of the immune system’s delayed hypersensitivity response – i.e., the reaction may take hours or days to develop. Interestingly, about 20% of the population is not allergic to urushiol. They can wander through poison ivy indefinitely and have no problems (the genetic variations responsible for this trait are certain to be an interesting topic for future work in the genomics and immunology fields). Another surprising fact was that many animals don’t have any type of allergic reaction to urushiol. Deer, goats, horses and cattle are fine with these poisonous plants. In fact, one of the suggested ways to get rid of poison ivy is to get a goat. This seems to be another very interesting genetics of immunity issue – how and why do some animals manage to not only evade these plants, but thrive on them. As more complete genomes are resolved the genes, SNPs, or genetic variations in general, will be uncovered and we should all be enlightened.
After the mad rush of the holiday season, I found a little time to catch up on reading, and stumbled across an astounding article in the NYtimes: New Genetic Test Asks Which Sport a Child was Born to Play, by Juliet Macur. A company called ATLAS (Athletic Talent Laboratory Analysis System) is offering a genetic test for kids which they claim will determine if your child is likely to be a super-athlete. Furthermore, they say it can tell you what type of a super-athlete your child may become, i.e., a sprinter or a weightlifter, so that you can begin preparations and training sessions for your child as early as one year old. This test is based on genotyping for an isoform of the muscle protein actinin, ACTN3. Actinins are an important family of actin-binding proteins.
Well, since I am a mom of a seven year old and a scientist that has spent more than fifteen years doing basic muscle research, this really caught my attention. My first thoughts were that this was morally appalling and scientifically impossible. All that I had learned and studied about muscle had led me to believe that muscles just don’t work that way. No doubt that the actinins are crucial to muscle function, but I thought that one muscle protein couldn’t do all of that. My off-the-cuff guess would be that at least 200 genes would contribute to such traits, and probably half would encode non-muscle proteins (genes related to drive, metabolism and many other factors would seem likely to be involved equally here). I wondered if I had missed some major development in the muscle field while enjoying motherhood, Continue reading
Do you still believe that monozygotic, or identical, twins are really genetically identical? Or that we are all 99.9% genetically similar to each other? Well I certainly did, and boy was I wrong! It turns out that CNVs (Copy Number Variations) are causing the “facts” some of us learned in Molecular Biology 101 to be rewritten. If you, like me, thought that what you learned years ago was still true, then there is a great webinar you may want to watch. It is brought to you by Science/AAAS, and it features three prominent experts in genetic variability, Drs. Charles Lee, Lars Feuk and Alexandra Blakemore. The moderator is Dr. Sean Sanders, who is the Commercial Editor of Science. Even those of you that are up to speed on the current research can find many interesting facts and learn about the new techniques used to study CNVs, or just genetic variability in general. It turns out that CNVs are much more prevalent than was previously thought. You hear so much about SNPs that it seems like they are the source of genetic variability that we should be most concerned about, but CNVs are catching up real fast. This new field is rapidly advancing because of major technology breakthroughs.
All of the panelists present a short talk highlighting the prevalence, importance and experimental limitations of studying CNVs and their role in normal human variability, as well as in disease. They present some of their own data and discuss the future direction of this young field. This is followed by a very interesting question and answer session where they allowed listeners to email their questions. It may even turn out that CNVs are the reason that your personality, IQ, height and weight differ from your colleagues, friends and family. So not only is this an exciting new field, but it is certainly one we can all relate to! Continue reading