2023 A to Z Challenge Blog: D is for DNA

Welcome back. Believe it or not, it’s a balmy 8 degrees Celsius (48 F) and sunny, but we are under the threat of a freezing rain episode later tonight and tomorrow, so I’m putting this together and getting it ready to fly into cyberspace a day early. Even if I lose power, the blog will be out there. My theme this year is Did You Know? and it’s a series of bits of knowledge I’ve gleaned over the ten years I’ve been a published author.

Today’s Did You Know involves the letter D and deals with DNA. Deoxyribonucleic acid (DNA) is the molecule that carries genetic information for the development and functioning of an organism. DNA is made of two linked strands that wind around each other to resemble a twisted ladder — a shape known as a double helix. It controls absolutely everything about who you are as a person, your appearance, your health, even whether or not you like certain foods. As you may recall in my first post, in order for you to exist, DNA from your mother’s egg (23 chromosomes) had to combine with DNA from your father’s sperm (23 chromosomes) to make you (46 chromosomes.) But those 46 chromosomes can be vastly different from one person to the next.

You would’ve learned some of this in science class as I did way back in the sixties when we learned the Mendel’s four postulates and laws of inheritance are: (1) Principles of Paired Factors (2) Principle of Dominance (3) Law of Segregation or Law of Purity of Gametes (Mendel’s First Law of Inheritance) and (4) Law of Independent Assortment (Mendel’s Second Law of Inheritance).

My science teacher had explained it with blue-eyed and brown eyes parents, which is why, having brown eyes and my husband having blue ones, I would’ve expected at least one of my three children to have brown eyes, since brown is a dominant gene. Not so. Not only are my three all blue eyed, my sister’s children with the same brown/blue ratio that I have also only had blue eyed children.

He never mentioned that other generations might get into the mix, and though while my eyes were brown, my father’s were blue. Thanks to my own research, I know that it isn’t as simple as the tall plants and short plants were. Every now and then, the ancestors get into the mix.

Simplified to the max, the explanation goes something like this. Each cell in the human body contains a nucleus filled with thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure. A gene is the basic physical and functional unit of heredity, and those genes are made up of DNA. Those gene cells form a genome that makes us human.

As much as it pains me to admit it, human DNA is not 100 percent unique.  In fact, the human genome is mostly the same in all people, but there are variations across the genome. This genetic variation accounts for about 0.001 percent of each person’s DNA and explains why we are all slightly different in appearance and health factors. The only people with the same DNA are identical twins.

Can you change your DNA? The short answer is not you personally, but Genome editing is a method for making specific changes to the DNA of a cell or organism. It can be used to add, remove, or alter DNA in the genome. Human genome editing technologies can be used on somatic cells (non-heritable), germline cells (not for reproduction) and germline cells (for reproduction).

Is gene editing safe?

The earliest studies showed that gene therapy could have very serious health risks, such as toxicity, inflammation, and cancer. Since then, researchers have studied the mechanisms and developed improved techniques that are less likely to cause dangerous immune reactions or cancer.

How much does gene editing cost?

Cell and gene therapies are expensive. Analysis by the Institute for Clinical and Economic Review (ICER) suggests the average cost of a gene therapy is between $1 million and $2 million per dose.

So, obviously, most of us will have to get by with the genes we have. For better or worse, you and your DNA are set for life.

Today, modern policing relies heavily on DNA evidence, especially in rape and murder cases. In the first book of my Harvester Series, The White Carnation, the police use DNA to identify a serial killer bent on creating his own dynasty. He selects the women, impregnates them, and after they’ve given birth, he kills them and discards the bodies since he no longer needs them.

Here’s the blurb:

He’s watching, waiting…
The last person disgraced reporter Faye Lewis wants back in her life is Detective Rob Halliday, her former fiancé, the man she blames for ruining her career and breaking her heart. But when she discovers her best friend’s mother murdered, she doesn’t hesitate to call him.
Breaking up with Faye after she unjustly accused him of sabotaging her career was a crippling personal blow for Rob, but he coped by burying himself in his work. For the past year, his team has been hunting the Harvester, a serial killer who ritualistically murders new mothers and vanishes with their infants. What Rob doesn’t need is another case, especially one involving his ex-fiancée. But, when the killer’s newest victim resembles Faye, all bets are off.
When Faye is assaulted in her own apartment, Rob realizes that not only are these cases connected, but Faye may also be the key to finding the elusive killer, providing Rob can keep her out of the maniac’s hands.
Realizing her vulnerability, Faye agrees to set aside their past to work the case together, but the more they investigate, the more complex the situation becomes. The mad man has an agenda, one that involves Faye. Can they catch the Harvester before he finds Faye and reaps another prize?

That’s it for me today. Find other bloggers and their posts here. https://tinyurl.com/3we8aa84

Come back tomorrow when I’ll give you a Did You Know? for the letter E. Enjoy your day.