Нэнси Кресс - Terran Tomorrow

The airlock gave onto a tunnel with two branches. One, sealed a short distance along, was an escape hatch that Zack hoped fervently would never have to be used. He hurried, holding his flashlight, along the much shorter tunnel. It connected to a similar branching outside Lab Dome. Airlock, decon, and he stood in the small space outside the bird lab and the mysterious, heavy third door. Up the stairwell to the young soldier on guard (didn’t they ever get bored, doing essentially nothing?), who unlocked the door to Lab Dome.

Zack raced into the conference room jammed with chairs, people, and the odors of too many bodies. Colonel Jenner sat at the head of the table. Was Jenner’s command post at the top of Enclave Dome more spacious than this? Zack had never seen it. Almost no civilian had, and only the most trusted soldiers.

“Sorry I’m late,” Zack said, squeezing into the only empty chair, beside Toni. Jenner frowned at him. Present were the heads of each research team, with some of their colleagues both military and civilian, plus some of the lab assistants. Four newcomers: two Army captains, Marianne Jenner, and Claire Patel. Neither of the Worlder scientists, which surprised Zack. Either Jane would not be able to keep up with the translation for this more technical meeting, or Jenner had decided on security grounds to exclude Ka^graa and Glamet^vor¡ from what was essentially a military briefing. Theoretically, these monthly briefings were classified, although in such close and crowded quarters almost nothing stayed secret very long. Major Duncan, whom Toni referred to as “Stonejaw,” wasn’t here; presumably Jenner had left her in temporary command at the top of Enclave Dome.

Surrounded by all those uniforms, Jenner looked tired but even more powerful than usual. “The emperor in state,” Toni said to Jason under her breath. She had the disconcerting ability to speak sotto voce without moving her lips at all.

Jenner said, “This briefing is in session. I’d like to introduce captains Mott and Darnley from Headquarters. Their mission is to update General Hahn.”

Zack blinked. Sending brass from Headquarters was a big deal, complicated and dangerous, unless these captains were already in the area. Why would that be? Something in Jenner’s posture suggested that this visit had been a surprise to him as well.

Jenner said only, “Captains Mott and Darnley will need to be brought up to speed on progress to date, so please start with the basics of your work. Dr. Yu?”

Dr. Jessica Yu, chief scientist for the base, also headed the vaccine unit. It seemed to Zack that she had always headed the vaccine unit, since the beginning of time. She’d been with the original Embassy team with Marianne. They had succeeded in creating a vaccine against R. sporii , and now Dr. Yu was trying to do the same for its weaponized cousin. At eighty-two, however, she turned more and more of the work over to others. She said, “Dr. Sullivan will present for the team.”

Major Denise Sullivan, once of the United States Army Medical Research Institute for Infectious Diseases, stood diamond-fiber straight, facing her listeners as diagrams from her tablet appeared on the wall screen behind her. Despite the lack of advance warning, her presentation was meticulous and detailed. Zack couldn’t tell how much of it the visiting captains understood, but by the end, one thing was clear: there was still no vaccine against RSA.

“Thank you, Major,” Jenner said. “Major Vargas?”

Juan Vargas, a brilliant but disorganized researcher perpetually in trouble for disregarding military protocol, headed the human immunity unit. His uniform, which he hardly ever wore, was missing a button. Toni, who respected both Vargas’s ability and his laissez-faire attitude toward spit-and-polish, changed her expression from fake to genuine interest, even though both she and Zack knew that Vargas’s unit had nothing real to report. They had made no progress toward tweaking the human immune system to cope with RSA. The variant of the protein that conferred natural immunity on a very few people was their hope; they had not been able to mimic it.

Marianne and Claire both asked a lot of questions. Zack watched Mott and Darnley. He became certain that they understood little of what they were hearing; Vargas was being too technical for laymen. Well, Zack could remedy that, maybe earning some brownie points for his team.

When Vargas wrapped up his presentation, Jenner said, “Dr. McKay?” And to the newcomers, “Dr. McKay heads the experimental unit. Please keep in mind that his research is the fallback position and may never be deployed, even if successful.”

Zack got to his feet. Before he could begin, Jenner added, “Since your area is the least familiar to all of us, Doctor, I hope your materials will begin with basics.”

“Yes,” McKay said. Definitely brownie points. He picked up a marking pen and pressed the button that retracted the screen into the ceiling. Behind it was an old-fashioned whiteboard on which someone had written “I WANT FUCKING REAL COFFEE!” There was no eraser. Zack swiped his sleeve across the board, leaving a smear. The marking pen had gone dry. Toni looked like she was suppressing giggles.

Two pens later, when he got one that actually wrote, he drew a diagram, talking as he sketched.

“Sparrows inherit two copies of every gene in their bodies, one from each parent. We are trying to alter one or more of those genes in order to develop two separate and distinct gene drives. Let’s call a sparrow carrying one copy of any altered gene ‘capital G.’ The other copy of the gene, plus both genes in unaltered wild sparrows, ‘small g.’ If the altered gene is dominant, then usually inheritance will go like this through successive generations:

“As you can see, fifty percent of the offspring carry the altered gene. Now each of these birds mates with wild sparrows, who are all small g:

“Now only one-quarter of offspring carry the altered gene. In the next generation, it will be only one-eighth, until the genetically engineered change effectively dies out. But with a gene drive, the situation is different. A gene drive utilizes a so-called ‘selfish gene,’ which is a bit of parasitic DNA that circumvents the laws of normal inheritance. It gets itself propagated preferentially by pasting a copy of itself into the matching chromosome inherited from the other parent, so that all of the offspring carry two altered genes. By piggy-backing on a selfish gene, a gene drive always gets inherited, like this.”

He sketched another diagram, suppressing the insane idea to draw birds instead of letters. Too bad he hadn’t had Caitlin “prepare his briefing materials.”

“Then those birds mate, and every one of their fledglings carries the alteration, on through the generations.”

Zack turned back to the table. “A gene drive creates a ‘selective sweep,’ spreading like wildfire and so eventually wiping out all other versions of that gene. This is a known phenomenon, occurring both naturally and through lab creations pre-Collapse, although there it affected insects, not birds.”

One of the new captains said, “But Dr. McKay, what are these two gene drives you’re trying to create going to do ?”