chromaffin cells

But let me get to the really key part here. Among the recovered materials was this.” Coleman held up a small white packet about half the size of a business card and less than half an inch thick.

“According to their clinical records, something like this is intended to be surgically implanted just beneath the skin of each Fixer. And this is an expanded polytetrafluoroethylene pouch that contains hundreds of millions of cells.”

“What type of cells?” asked Church.

“Well, you see, boss, that’s the really interesting part. RNA-Seq showed that they were most likely chromaffin cells. Those are the cells in the adrenal cortex that are responsible for the release of catecholamines.”

“Cate…?” began Wilson, fumbling with it. Coleman stepped right in.

“Catecholamines are the molecules responsible for the body’s fight-or-flight response, which was interesting by itself. But when we dug down and did whole genome sequencing, we found a number of genetically inserted tet-on promoters. Specifically, they were attached to inserted versions of DOPA decarboxylase, dopamine β-hydroxylase, and phenylethanolamine N-methyltransferase.”

“I have no idea what that means.” Coleman, who was in gear and very excited, tried to scale it down, but he was a lab rat and very rarely had to explain these things to ordinary mortals.

“Tet-on promoters are a little bit of DNA that can be used to control when a gene is expressed. Think of it as a light switch for a gene. But this switch is flipped by adding tetracycline. It has been used in biotechnology for a long time, but this isn’t just some off-the-shelf version. This is highly specialized to turn on very fast and make huge amounts of the genes. And the genes they control are the genes in the synthetic pathway to turn L-Dopa into norepinephrine and adrenaline.”

-Relentless pg. 341-342, Kindle Edition.