A Wish the Heart Makes: Fornever in Blue Genes by Tigger Chapter 12: Understanding "Eureka!" Mandy shrieked, causing Cat to come off her couch into a fighting stance. "That has to be it!" She jumped up and moved to the Nurse's station. "Call Dr. Bob West. I need him. Now!" The voice was all woman, but the tone of command was one every senior employee of BioCybernetics would recognize in an instant as "the Boss". Teri quickly swiped a finger across a touchpad on her panel and spoke normally. An immediate response answered her call. "The Doctor is on his way, Sir . . . errr, Ma'am," Teri fumbled. For the next four hours, Cat watched in amused tolerance as the two scientists huddled around the small screen of Mandy's computer display. More than once, the interplay became loud and heated. Finally, Bob had stormed off. Cat cocked a questioning eyebrow at Mandy who was visibly trying to control her mirth. "God, Cat, that is the most fun I have had since I woke up. I had forgotten how much I love jerking his chain, and I think . . ." Mandy paused for a moment considering her next words. "I think, that Bob has a hard time remembering that under all this pulchritude is the same guy he has been banging heads with, intellectually speaking, for more than two decades." An insulted little smirk twisted her features. "Just because he gave me tits doesn't mean my brain disappeared along with my penis." Cat howled at Mandy's indignation. "Welcome to 21st Century Womanhood, luv. An era of gender-based equal opportunity under siege from a legal and regulatory based backlash against some of the more extreme outcomes of the 20th and 21st Century feminist movements. Women have to prove themselves in the workplace everyday, just like men. You still think like the chauvinistic hunter-gatherer of ages past and expect automatic respect from your fellow male. Only Bob sometimes forgets, and reacts to that cute feminine skin you're wearing instead of that shared masculine outlook." She laughed again, bringing a rueful smile to her charge's face. "So, what did you two geniuses decide?" "Oh, that I just *can't* be right and that *he* is going to *prove* that I can't possibly be correct." That got Cat's attention. "And why, pray-tell, can't you be right?" "Because the solution is so easy, all he had to do was play with a couple of numbers to see what might be going on. Only problem is that it flies in the face of what we supposedly know about genes. It is still sex linked, Cat. Only instead of one gene on one chromosome, the effect derives from two gene sites on either of two possible X chromosomes in the female. The reason survivability is so disparate between males and females is that males have only one X chromosome, so both sites have to be right for him to survive." Two days passed before either woman saw Robert again. A very rumpled, almost painfully fatigued Dr. West dragged himself into the security apartment while Morag spotted for Mandy during a resistance and free weight session under Cat's watchful eye. He said nothing, just moved to a nearby chair and sat watching the exercise. When Morag finally let Mandy stop, she noticed Bob for the first time and strolled over to where he sat. "Decided you are going to talk to me again, old friend?" she asked with a hint of laughter in her voice. Fatigue circled eyes lifted to meet hers. "It would appear you are correct. I have never seen anything like it before, but then, we know that the folks who did the GPD never considered genetically based gender transitions in their studies." With some difficulty, Mandy controlled the urge to gloat, and settled down beside Bob and asked, "So, was it a dual gene interaction?" "Apparently. Two gene sites on the X chromosome that the GPD decided didn't have any discernable effect on modern homo sapiens. Who knows why - maybe they were leftovers from early humanid evolution that have no current purpose - sort of like the tailbone that no longer hooks to a tail. Anyway, I ran a sorting routine against the X chromosome since the effect was so clearly sex linked. I found ten unmapped sites that fit that pattern you described, but equally importantly, had no partnering site on the male Y chromosome. That took twenty minutes." Mandy's brows went up in disbelief. Twenty minutes on a state-of-the-art quantcha computer was like forever in real time - the equivalent of almost the same number of years of computing on an old twentieth century super computer. He continued. "I spent the next 24 hours doing clinical clonal studies to try and isolate the correct site, and the last 24 hours confirming my results. I can now show, at least to my own satisfaction, that two gene sites, both sites previously listed in the GPD as having no identifiable genetic effect, interact during a gender change and determine whether the subject will survive or not. It also explains why a subject that succeeded going from male to female invariable dies going back. The successful gene set that permits a new female to survive is the one that assures the reverse transformation is nonviable." By now, Cat was seated with them. "I hope the hell you two know what you are talking about, because I am lost." Mandy smiled at her friend. "It is just like I explained earlier, Cat. Our experience is that genes normally operate independently, but in this case they don't. In the case of changing sex, going from male to female, the process replicates the missing genes on the smaller Y chromosome by duplicating the genes on the existing X for those genes that don't do anything, only "fixing" those that result in an undesirable recessive like color blindness. Okay so far?" "Yeah, basic biology." "Okay, what he is saying that two gene sites on the X chromosome determine whether a gender change, under our process, lives or dies. For the sake of argument, call them gene A and gene B. Each gene has two possible types, call them A1 and A2, B1 and B2." By now, Cat was sketching on paper to get a visual idea of what Mandy was saying. "For a successful male to female transition, there is only one viable gene set because there is only one X chromosome in a male. The only A gene must be A1 and the only available B gene must be B1, and that only happens 25 percent of the time. On the other hand, there are two A sites and two B sites in a female XX pair. Therefore, if at least one of the A's is A2, and one of the B's is B2, the female to male transition is viable. That has a probability of 56.25 percent. Okay?" Cat wrote and sketched furiously for a moment. Mandy realized she was writing down all the possible combinations of genes at the A and B sites and hand calculating the probabilities. Finally, she nodded. "Okay, but what did Bob mean when he said that the successful male to female was assured to be non- viable?" Mandy grimaced, and Bob sighed resignedly. He took up the explanation. "That, I am afraid, is our fault in the way we generated the second X chromosome. The transition process ignored any unidentified GPD gene sites during transition and merely replicated those X sites existing on the one X chromosome the male possess. To survive the transition, therefore, the male's X chromosome must be A1B1, so both of the new woman's X chromosomes are also A1B1. Therefore she lacks the A2 and B2 gene combination required for a viable female to male transition." "Shit," Cat muttered in disbelief. "Can you fix it? I mean, you change genes everyday when you are healing things." Dr. West shook his head slowly. "We don't know, Cat. Changing one gene on one chromosome when we know what that gene does is one thing. We don't have any experience fumbling with interacting highly close-coupled pairs of genes. Hell, I can't even simulate the effects because I don't know what will happen. I simply don't know what those damned genes really do. Besides messing up gender changes, that is. No, the only way we will learn anything worth knowing is to do real experiments the old fashioned way and play with a lot of clonal cultures." Cat took one look at her old friend, who had, against his will, been turned into everything she desired in a lover. Her heart twisted and then she turned steel hard eyes on Robert. "Well, when did you start them, and how long before you know anything?" Shock, then anger lit the normally placid face of the older man. His mouth opened and shut several times in rapid succession as he bit back one retort after another. Then, he stood abruptly, turned on heel, and stormed out of the apartment past an amazed Teri Richards.