“You were trying to see if there is a genetic difference between them that would explain their reactions,” said Sarah, thinking aloud. She was annoyed that Emile had not come to her immediately, but she now saw that he and the others had taken the same steps that she would have recommended.
“Yes, but we can’t find a difference. The mice are all clearly from the same gene pool.”
“Call the labs that supply the mice. See if they can verify the lineage.”
Emile nodded. Sarah began clicking through more screens, looking at the various graphs and comparing the results from the different groups of mice. It was obvious that Emile was right—these mice should have had predictable reactions to the viral infection, but that was clearly not the case. In some cases the high dosage of virus killed the mice, and in some it did not. In some groups the low dosage killed the mice, and in others, it did not. The results made no sense.
“And did you put some tissue samples under the microscope to see if the virus was present in the mice that are still alive?” asked Sarah.
“No,” said Emile, “but I’ll get right on it.”
“Okay, let’s see what the mouse supplier says and what the tissue samples show us. I’m going to go speak with Kevin and see if he might remember anything from when he got us the mice.”
When Sarah left her office she headed down the hall to where the techs generally worked. It was a smaller room, and since many of the techs were undergraduate students, they often brought their class work and sat at tables when there was not too much going on in the main lab. She was glad that it was not a distant walk. Her leg was beginning to ache again. As she entered the room, Sarah scanned the tables and quickly found Kevin sitting close to a window, poking away at his phone.
“Kevin,” she said, once she had wrested his attention from the monopolizing device. “We seem to have a problem with mice we’re using for these new experiments.”
Kevin looked at her blankly.
“The mice,” she repeated. “The mice you got us for the experiments for the Laptev virus. Something is wrong with them.”
Kevin raised an eyebrow as his expression changed to a slightly different kind of confused.
Sarah closed her eyes, realizing this was a task that she should have delegated. She had far too many problems to be speaking with this young man who seemed to have no life outside of his phone. She tried once more, this time conveying her ideas in staccato thoughts that he might be able to grasp before his mind wandered.
“The mice are reacting discordantly to the same stimulus. They should all have the same reaction. It doesn’t make sense. I’d like you to check with the people who work in the vivarium, and see if you can find anything that might give us a clue as to why the mice are acting differently. Anything at all. Do you think you could have an answer for me by tomorrow?”
Kevin nodded and Sarah decided that that was good enough.
CHAPTER 14
The next morning Sarah met with her group of researchers again. “As you all know by now,” she said, “we seem to have a problem with our mice here, and it could be egregious. Emile, Drew and Shane have run several tests using the mice as hosts for the Laptev virus, and there seems to be a discrepancy in the control group. Some of them contract the viral infection and die, while others contract it and live perfectly well. And the dosage we gave them, which should affect the rate of infection and illness, seems to not have the expected result.”
She paused and a furrow creased her brow. “So far we cannot find a pattern, and it certainly makes no sense that if the mice were all identical to begin with, there would be such differing reactions to the virus. I’ve asked several of you to follow up with some further investigations, and I’d like for all of us to pay close attention to see if between us we can crack this nut. Emile, will you please begin”
Emile nodded. “We took samples from striated muscles, as well as different organs, to see if there was a difference between the mice that lived, which we’ve called the ML’s, and the ones that didn’t make it, which we’re calling the MBD’s.”
“MBD’s, right,” said Shane, chuckling under his breath as if he was just getting a joke. “I just love that name.”
There were a few more giggles from Tally and Miquela and then Emile said, “It was Drew’s idea.”
Sarah was amused, in spite of herself. “Drew, would you like to share what that acronym means?” asked Sarah, a small smile playing on her lips.
All eyes turned to Drew and he said, “Well, okay, it was a hasty decision.” When no one responded after a few more seconds he said. “All right! Don’t get bent out of shape. It stands for Mice that Bit the Dust, okay?”
Everyone chuckled for a moment and then Emile continued with his account. “We preserved the dead mice as soon as we found them, to prevent tissue breakdown that might impair our ability to see what was going on. We took the samples in triplicate, fixed and stained them and examined them early this morning.”
“In most tissues and organs, we saw no difference between the two groups. However, if you’ll click on the picture there,” said Drew, indicating a file that revealed an enlarged photograph. “We were almost through examining the tissue samples when we got to the brain tissue slide. Since we hadn’t seen any differences so far on any of the other organs or the muscle tissue, we were planning to do an ELISA assay with the blood, using antibodies from human HeLa cells to detect the presence of the virus, but before we even got to that, we saw this.” Here Drew stopped and pointed to a dark circular shape with the tip of his pencil.
Sarah glanced at the slides of tissue projected on the screen. She saw that in some of the mice, the regularly shaped pink cells of the brain, long and sinuous, had large, dark purple circles inside the main body of the cell, with lots of dark little dots. She raised her eyebrows in surprise and asked “What are those? They’re not supposed to be there, are they?”
Emile shook his head, no. “I’m not certain what they are, but some of the mice have them and some don’t. Whatever they are, they don’t seem to be having a negative health effect on the mice. They look and act perfectly normal. No changes in eating, sleeping or learning behavior.”
For a moment everyone sat there looking at the translucent, pink images of brain cells on the slides on the screen. The purple dots were not in all the slides, but from what Sarah knew, they should not have been in any of them.
Sarah sat back and crossed her arms as the full impact of what she had been told began to sink in. Those little dark purple dots were definitely a problem. A humongous problem.
Or maybe she was jumping to premature conclusions. Perhaps if they had only taken samples from the dead mice, the dots could have been a product of metabolic decay. “You took these samples from living mice as well?” she asked.
“Yeah, this picture on the screen is from a biopsy of a living animal,” he said.
Sarah felt her shoulders tightening. “So the results that we have gathered over the past several weeks with the mice are pretty much meaningless?” she asked, already knowing the answer.
Emile and Drew kept their eyes fixed on the image of the brain cells on the screen, but Emile’s face was drained of color.
Sarah closed her eyes and shook her head. “I don’t believe it! Could there be a mistake? Maybe the slides were dirty before the mounts were made…” It was a lame suggestion, she knew. The dots were clearly stained with the same dye as the cells and there was no way that they could be random dust motes.
“We’ve double and triple checked,” said Drew, obviously as frustrated as Sarah and Emile. “There’s no doubt that some of the control mice are contaminated. And whatever has contaminated those mice is definitely there in those brain cells.”