A Discovery of Witches(68)

“Genetic material that distinguishes us from humans,” Matthew said, “as well as material that regulates cell function or is what scientists call ‘junk DNA.’”

“It’s not junk, though,” Marcus said. “All that genetic material has to be left over from previous selection, or it’s waiting to be used in the next evolutionary change. We just don’t know what its purpose is—yet.”

“Wait a minute,” I interjected. “Witches and daemons are born. I was born with an extra pair of chromosomes, and your friend Hamish was born with a single extra chromosome. But vampires aren’t born—you’re made, from human DNA. Where do you acquire an extra chromosome pair?”

“When a human is reborn a vampire, the maker first removes all the human’s blood, which causes organ failure. Before death can occur, the maker gives his or her blood to the one being reborn,” replied Matthew. “As far as we can tell, the influx of a vampire’s blood forces spontaneous genetic mutations in every cell of the body.”

Matthew had used the term “reborn” last night, but I’d never heard the word “maker” in connection with vampires before.

“The maker’s blood floods the reborn’s system, carrying new genetic information with it,” Miriam said. “Something similar happens with human blood transfusions. But a vampire’s blood causes hundreds of modifications in the DNA.”

“We started looking in the genome for evidence of such explosive change,” Matthew explained. “We found it—mutations proving that all new vampires went through a spontaneous adaptation to survive when they absorbed their makers’ blood. That’s what prompts the development of an extra chromosome pair.”

“A genetic big bang. You’re like a galaxy born from a dying star. In a few moments, your genes transform you into something else—something inhuman.” I looked at Matthew in wonder.

“Are you all right?” he asked. “We can take a break.”

“Could I have some water?”

“I’ll get it.” Marcus hopped up from his stool. “There’s some in the specimen fridge.”

“Humans provided the first clue that acute cellular stress from bacteria and other forms of genetic bombardment could trigger quick mutations, rather than the slower changes of natural selection.” Miriam pulled a folder out of a file drawer. Opening it, she pointed to a section of a black-and-white graph. “This man died in 1375. He survived smallpox, but the disease forced a mutation on the third chromosome as his body quickly coped with the influx of bacteria.”

Marcus returned with my water. I took the cap off and drank thirstily.

“Vampire DNA is full of similar mutations resulting from disease resistance. Those changes might be slowly leading to our extinction.” Matthew looked worried. “Now we’re trying to focus on what it is about vampire blood that triggers the generation of new chromosomes. The answer may lie in the mitochondria.”

Miriam shook her head. “No way. The answer’s in the nuclear DNA. When a body is assaulted by vampire blood, it must trigger a reaction that makes it possible for the body to capture and assimilate the changes.”

“Maybe, but if so, we need to look more closely at the junk DNA, too. Everything must be there to generate new chromosomes,” Marcus insisted.

While the three of them argued, I was rolling up my sleeve. When the fabric cleared my elbow and the veins in my arm were exposed to the cool air of the laboratory, they directed their freezing attention at my skin.

“Diana,” Matthew said coldly, touching his Lazarus badge, “what are you doing?”

“Do you still have your gloves handy, Marcus?” I asked, continuing to inch my sleeve up.

Marcus grinned. “Yeah.” He stood and pulled a pair of latex gloves out of a nearby box.

“You don’t have to do this.” Matthew’s voice caught in his throat.

“I know that. I want to.” My veins looked even bluer in the lab’s light.

“Good veins,” Miriam said with a nod of approval, eliciting a warning purr from the tall vampire standing next to me.

“If this is going to be a problem for you, Matthew, wait outside,” I said calmly.

“Before you do this, I want you to think about it,” Matthew said, bending over me protectively as he had when Peter Knox had approached me at the Bodleian. “We have no way of predicting what the tests will reveal. It’s your whole life, and your family’s history, all laid out in black and white. Are you absolutely sure you want that scrutinized?”

“What do you mean, my whole life?” The intensity of his stare made me squirm.

“These tests tell us about a lot more than the color of your eyes and your hair. They’ll indicate what other traits your mother and father passed down to you. Not to mention traits from all your female ancestors.” We exchanged a long look.

“That’s why I want you to take a sample from me,” I said patiently. Confusion passed over his face. “I’ve wondered my whole life what the Bishop blood was doing as it pumped through my veins. Everyone who knew about my family wondered. Now we’ll know.”

It seemed very simple to me. My blood could tell Matthew things I didn’t want to risk discovering haphazardly. I didn’t want to set fire to the furniture, or fly through the trees, or think a bad thought about someone only to have that person fall deathly ill two days later. Matthew might think giving blood was risky. To me it seemed safe as houses, all things considered.