It’s in Your Genes!
When we were kids, my brother and I would invent secret codes and send one another messages. We weren’t particularly clever about it, though. I seem to recall that a number 1 meant the letter A, a number 2 was B, and so on. And half the time the message would come out as gibberish because one of us, the sender or the receiver, misunderstood some agreed convention. “Time for lunch” might come out “slime for lunch!”
With smart phones in nearly every pocket (not mine, by the way – in fact, I just caved into my family’s pressure to get a dumb phone a few weeks back), the importance of accurate interpretation of words and even “tone of voice” in writing has become more critical than ever. A text from the boss that simply reads, “please come to my office right away” could set off a firestorm of emotions: Am I getting a raise? A promotion? The sack? Maybe you should hide in the bathroom and hope the boss forgets whatever it was he wanted to see you about in the first place!
My high school daughter is studying Spanish, so when my wife and I arrived after cross country practice to pick her up yesterday, I wanted to tell her estamos aquí (for those of you who don’t live near the Mexican border, that means “we’re here”). But since I hate typing on that tiny digital keyboard, I tried speaking it into my wife’s iPhone: “Still most sucky” was the message she got. Close enough, I guess.
Morse code was a pretty slick invention. But it’s got nothing on DNA!
Communication is complicated. First there is the original intent of the message. Then it must be delivered in a way that conveys that intent. But then it has to be properly interpreted and in some way, intellectually or kinetically, acted upon.
How does all this happen with the language of DNA? How does a living thing take a string of chemicals arranged in a pattern and act upon the instructions it finds there?
It’s actually really cool.
DNA is long-term stored information. Each cell of a creature gets a complete copy of all the DNA that creature needs to survive. But it only gets that one copy, so it guards it with its life, literally. If DNA gets damaged beyond repair, most cells are programmed to kill themselves to make certain that their misinformation doesn’t get passed along to the next generation.
To understand how the organism accesses its DNA instructions, we have to understand a basic principle. Each gene, made of DNA, gives exact instructions for making a specific protein. And proteins are the business molecules of the cell. When we say that someone has their father’s height, what we mean is that he or she inherited a particular gene that instructed many cells to produce a protein that then led to a particular height. I’ve often been told that I have my mom’s hair color and texture. That just means I inherited from her specific genes (DNA sequences) that gave instructions to make specific proteins that were then responsible for pigmenting my hair blond and introducing a few curls to it.
One gene instructs the production of one protein that then does something.
But since we don’t want all of our genes being expressed all the time (imagine continually making insulin or if our growth hormones never stopped being produced after puberty), there is an intermediate information form between the DNA and its protein product: RNA, or ribonucleic acid. RNA is central to an organism’s ability to regulate the expression of its genes.
RNA shares much in common with DNA, with a few minor exceptions that are inconsequential for our current discussion. But we do need to know where RNA comes into the picture.
When an organism needs the protein product of a particular gene, it sends a complex set of other proteins to the gene, straight to the DNA, to a region that acts like a light switch. When those proteins bind the DNA at that location, they flip the switch on – making an exact copy of the gene, only in RNA language rather than DNA language. This short-lived molecule is called a transcript, because it is produced by transcribing from one dialect of nucleotide language into a closely related one. The RNA transcript is then bound by another complex set of molecules called a ribosome that translates it from nucleotide language to protein language and thus directs the production of a new protein.
In my house growing up, my mother’s cookbook needed to be protected from egg and butter and hollandaise sauce, so she would copy the recipe she needed onto an index card and bring that into the kitchen where she would work her culinary magic.
The recipes themselves are like DNA, long-term instructions for making something that you might want to make today or some other day in the future. The copied version of a single recipe onto an index card is like the RNA transcript, not meant to last forever, but useful for the moment and expendable compared to the recipe itself. Finally, the baked ziti or pumpkin and cream cheese French toast is like the final protein: lovingly, precisely made according to the instructions stored in the DNA.
Remarkably, all living things use this system of DNA to RNA to protein as the central theme of their biochemistry. Even more astounding is that the language itself, the combinations of nucleotides that have meaning for protein synthesis, is the same in the mosquito as it is in the golden trout. As the preeminent geneticist Francis Collins said, “no tower of Babel was to be allowed in the language of life.”1
This precision and complexity (and we have just scratched the surface!) has to be among the most wonderfully beautiful things that happens on Planet Earth. And it occurs billions of times per second in you alone. Wow.
Questions for thought
College textbooks can teach us something of life. Life itself can teach us more. Romans 1:20 says For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse. What can we learn of the Father’s eternal power and divine nature from the modern scientific discoveries of DNA, RNA, and protein? Resist the temptation to oversimplify your answer to this question.
When we see a colorful butterfly on an intricate flower, we are drawn to the beauty of both and count ourselves blessed to have experienced them in the same place at the same time. Then we dig deeper and realize that the colors and patterns of the flower are intended to attract the butterfly, who then unwittingly carries pollen to the next flower, continuing its life cycle. How does a deeper understanding of the complexities of God’s creation influence your sense of awe and wonder at the Creator?
Creator God, in your wisdom you designed a language that instructs the biology of all living things. Its beauty and wisdom and ingenuity reflect your own. Teach us to seek a deeper understanding of you through your Word, your Holy Spirit, and your Creation. Let us never fear to peer deeper into the mysteries you are revealing to us. Amen.