The Cassandra Complex - Brian Stableford [124]
Unless, of course, Lisa thought, she had her remaining stock taken out while she was in her twenties and stored in liquid nitrogen.
“What I tried to do,” Morgan went on, “was to introduce retroviruses into pregnant mice, aiming them specifically at the eggs within the fetal ovaries. The idea was to secure a vast collection of ready-transformed pre-oocytes, which could then be extracted from the aborted fetus. It would have been authentic mass production, on a time scale measurable in days rather than weeks, let alone the years it takes to bring transformed sheep and cows to adulthood. You can see what a boon a system like that would have been to my search for the ideal addressable vector.
“Unfortunately, it wasn’t as easy as it sounded. Nature’s genetic engineers are unreliable slaves—they have their own agendas, and a lot of those agendas are what the man in the street calls diseases: colds, colics, and cancers. The womb has it own agenda too. It has a system programmed into it, and when you have wombs within wombs, things can get very complicated. I couldn’t get effective transmission across the placenta. I had to switch my attention to newboms, although it seemed like a terrible waste. So many eggs have already gone by the time a mouse is born, and the rest are dying in droves day by day. I thought it might at least be possible to do something about the latter problem, so I modified my retroviruses yet again, incorporating a control gene that was supposed to stop the oocytes from committing suicide.
“That one worked. In fact, it worked far better than I’d hoped. In coupling it with the rest of the package, I’d somehow contrived to produce a synergistic effect—one of those million-to-one shots of which I’d always been so flagrantly contemptuous. When you have a hundred thousand genetic engineers trying out hundreds of novel gene combinations every year, though, the laws of probability will give you a million-to-one shot every month. Mine was the only one I ever got in forty years of trying, but it was a big one.
“In those days, we were only beginning to get used to the first principle of genetic engineering—you can never do just one thing—so I hadn’t figured multiplicity of effect into my plans, let alone synergy, but they sure as hell came out in my results. Do you ever come across genetic mosaics in your police work?”
“Occasionally,” Lisa confirmed. Mosaics had first attracted attention when biologists contrived to fuse the embryos of two different species. The first sheep/goat hybrids had been produced in the 1990s, and the revelation had prompted people to wonder how often the same thing happened in nature. Whenever a single fertilized egg divided into two to produce identical twins, the result was obvious, but when two fertilized eggs fused to produce a single individual, there was no easy way of telling that the resultant individual was a mosaic. Until DNA analysis came along, there was no way of knowing how many cows in the bam or people walking the streets were actually patchworks of two distinct but closely related genomes. Human mosaics were even rarer than pairs of identical twins, but a world of nine billion people had to contain millions. Lisa had run across half a dozen human mosaics while conducting DNA analyses in the police lab.
“In that case, you probably know that animal mosaics were often created mechanically back in the 1990s. It was an early alternative to cloning that lost fashionability when nuclear-transfer techniques improved. The mosaics I created with the aid of my trusty retroviruses were a kind that nature had never contrived, though. My retroviruses produced a strain of mice whose egg-filled ovaries became benign cancers—not merely benign in the accepted sense that the cancers were harmless, but in a much stronger sense. The transformed eggs became capable of fusing with one another to produce zygote-like bodies