How epigenetics and pseudogenes satisfied @eegiorgi’s appetite for a real human predator

“Whether it’s X-Men, zombies or human/animal hybrids with enhanced senses, epigenetics gives writers a new realm of phenomena to explore. One can’t help but wonder: is reality truly stranger than fiction?” – E.E. Giorgi

Thank you, Elena Giorgi, for your fascinating contribution to the science articles in the May 2015 issue of  @PerihelionSF —

      

E. E. Giorgi is a computational biologist at the Los Alamos National Laboratory, an award-winning photographer, and a writer. She normally works in HIV research. Her debut novel, “Chimeras,” was a 2014 International Book Award winner.

Making Real Life X-Men by E.E. Giorgi

EVEN THOUGH I’VE NEVER BEEN a huge fan of the human/animal hybrid in science fiction (Sabretooth, Beast, “The Island of Doctor Moreau”), the concept has always intrigued me. Not so much the genetic explanations, rather, the idea of a predator in human disguise. After all, before we developed the opposable thumb that gave us the ability to hang from trees, we were already predators, weren’t we? And yet, none of the human mutation scenarios out there ever satisfied my appetite for a real human predator. That’s how, in my quest, I came to learn about epigenetics and pseudogenes.

Pseudogenes are bits of DNA that we inherited from our ancestors and, at some point during our evolution, got turned off. In other words, they stopped producing the protein they were originally coding for. For example, TAS1R2, the gene that encodes for the taste receptor for sweetness in humans is, in fact, a pseudogene in felines. As a consequence, cats don’t have a sweet tooth: they literally can’t taste sweetness.

Our DNA is riddled with regions that we inherited from our ancestors. We inherited mitochondria from bacteria, and roughly ten percent of our genome from viruses. As we evolved from amphibians to reptiles to mammals, new genes arose and the old ones became inactive and turned into pseudogenes. Can these old, inactivated genes ever be turned back on? As it turns out, some can. For example, viral pseudogenes that we inherited millions of years ago are now expressed in the placenta. Furthermore, the largest set of known pseudogenes is made of olfactory receptors, which can indeed be reactivated and become functional again. Ever wondered why pregnant women suddenly start smelling the weirdest things?

All this raises the question: how can genes be turned on or off? And what does it mean for a gene to be on or off? To answer these questions we need to take a step back and look at our own evolution.

Read more (for free!) in the May 2015 issue of Perihelion Science Fiction ezine

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“Fly Me to the Moon” is the most popular tourist attraction in Luna City. The theme park consistently outdraws Six Flags. Update 12-MAY-2015. By Bill Wright.

Further Reading

The Seductive Allure of Behavioral Epigenetics.
Epigenetic Differences Associated With Prenatal Exposure to Famine.
Genetics and Epigenetics of Obesity.
Maternal Obesity and Fetal Metabolic Programming.
The Epigenomics of Cancer.
Epigenetic Regulation on Gene Expression by Physical Exercise.
Epigenetic Reprogramming of Host Genes.
Control of HIV Latency by Epigenetic and Non-Epigenetic Mechanisms.