Monday, August 25, 2008

The human genome and epigenetics

So as many of you may or may not know, they've mapped our entire human genome. What that means is that they have long lists of letters that are put together in certain ways that map out exactly what protein-coding genes, RNA, etc. go where, and do what in the human body. Our genome is within percentage points of being the exact the same as rats, monkeys, and a few other mammals. For a long time people have thought that our health, our psychological tendencies, our addictions, and our physical appearance to be the sole product of our genes. Recently research has been illuminating the other side of that argument. I recently watched a NOVA special called Ghost in Your Genes.

Take for example, identical twin girls, according to our understanding of the human genome they have the exact same set of genes and DNA. Those twins reach the age of 60, and one twin develops cancer while the other one does not. Take another set of teen adolescent identical twin boys. At the age of 3 one boy starts to drift into his own world and has a harder time interacting with human beings, or anything live. He starts to obsessively spit on the computer monitor and wipe it clean, over and over and over again. He was eventually diagnosed with severe autism. The other twin boy excels at school, is an athlete, and talks of the colleges to which he will apply.

If genes are the only things at play here, how do identical twins, with exactly the same genes and DNA, divert so greatly in the physiological or psychological symptoms they present?

This is where epigenetics comes into the story. Taken directly from Wikipedia:

Molecular basis of epigenetics

The molecular basis of epigenetics is complex. It involves modifications of the activation of certain genes, but not the basic structure of DNA. Additionally, the chromatin proteins associated with DNA may be activated or silenced. What this means is that every cell in your body has the same instruction manual, but different cell types are using different chapters. Your neurons, for example, contain the DNA instructions on how to make your fingernails- but in neurons, those genes are turned off. Epigenetic changes are preserved when cells divide. Most epigenetic changes only occur within the course of one individual organism's lifetime, but some epigenetic changes are inherited from one generation to the next.[9] Specific epigenetic processes include paramutation, bookmarking, imprinting, gene silencing, X chromosome inactivation, position effect, reprogramming, transvection, maternal effects, the progress of carcinogenesis, many effects of teratogens, regulation of histone modifications and heterochromatin, and technical limitations affecting parthenogenesis and cloning.

Epigenetic research uses a wide range of molecular biologic techniques to further our understanding of epigenetic phenomena, including chromatin immunoprecipitation (together with its large-scale variants ChIP-on-chip and ChIP-seq), fluorescent in situ hybridization, methylation-sensitive restriction enzymes, DNA adenine methyltransferase identification (DamID) and bisulfite sequencing. Furthermore, the use of bioinformatic methods is playing an increasing role (computational epigenetics).

These epigentic chemicals can tell which parts of a strand of DNA to be expressed, and which to be turned off. These epigenetic switches can be mediated, and modified by diet, environment, stress levels, and even the stress levels and amount of food your grandparents had to eat. I recommend the "Tale of Two Mice" interactive on the URL I listed above.

Nuture is getting more press, it's getting more research, and for this little bodyworker, the line between mind and matter is thinning at an outstanding rate.


Monday, August 11, 2008

Reunions, family, and driving...oh my

The boy and I finally got back into Seattle after our week long sojourn to Idaho, Utah, my 20th high school reunion, and more family than you can shake a stick at.

It was a very nice drive and much shorter than I remember it being. We stopped in Idaho to stay the night and see my father, my step-mother, my nephew, half-sister, niece I had not met yet, and my unborn niece that is due to make her appearance any day now. If you feel you need a flow-chart to keep track of all the family, join the club. It was good to see them all, and I hope to be able to get down there more frequently, and hopefully they can make it up north on occasion.

We then headed to Utah. Highlights with the family included a delightful afternoon of pedicures and dish with my sister The Rookie, a big free for all dinner with the bulk of my siblings (half, step, real, fake, and everything in between), with my sister A being one of the very missed absentees at this fete. I did a few cranial sacral sessions with the family, which proved to be a very good learning experience. Ly and I connected with some folks we went to school with in Cedar City, Utah that we hadn't seen in about 15 years. Had a lovely dinner with my sister of Chaos in her cute little house, over which I am still harboring envy. We managed to log some good pool time, some good chat and catch up time with family, friends and my precocious nieces and nephews. It was good to see my brother who I don't get to talk to as much as I would like.

The 20th reunion was a mixed bag. At least 4 of the people I was wanting to see didn't come to the reunion, but I did manage to catch up with a VERY old friend with whom I used to totter around in diapers (as infants to clarify for those who were wondering). It was good to see him and his lovely wife. I did feel a little out of place as the majority of people had an average of 4 children. I was truly one of the minority in that I didn't have any children. When telling many folks at the reunion that I was not able to have children, I got that "Oh, you poor thing how lonely your life must be" look. Folks were honestly mortified as though my life just wasn't the same as it would have been if I had bred. I took it all with a grain of salt, spoke of the amazing things with which my life is currently filled, and moved on to other subjects. I did get a little bit of the, " still doing drAHma? You were always so good at that drAHma." It seemed to me that many of the popular student body folks were still gathered together in the same configurations I remember from high school. The only difference is that they had about 20 more pounds on 'em, more lines around their eyes, and many were sporting fake tans. They chose a good soundtrack for the evening, and I don't care who knows it, 80's music ROCKS!

Ly and I drove straight through on our way back to Seattle. I had to get back to work, and I needed a day to chill before doing so. Plus, this past weekend was filled with weddings, a final party for the massage school I went to, and our 12th anniversary on Sunday.

So that's the skinny, thank you to the family for making it a very adventurous, playful, and entertaining visit.