The Victoria and Ernie’s rubber duck-Y

The verdict finally came. A team of 284 genetic explorers has just come back from their "innerspace" exploration, sequencing the X chromosome to tell us something important in a landmark publication in the journal Nature. After reading the journal, this is how I understood it. Think water vessels. If the X chromosome is the equivalent of Victoria, Magellan’s circumnavigating ship, loaded with ancient and recent evolutionary loot, the Y chromosome, relative to the X, is more like, well, Ernie’s rubber duck-Y, good for one main thing: squeaking sex differentiation. I know, I know. I have too much fun with the Y chromosome when science comes up with new knowledge on X and Y stuff, but who would not? I can now hear male howling and banging, crying "foul" at the liberties I take with my metaphors. It does not take a certified historian to take a look back at most of history or even for a female science writer like me to survey the Ys in all their self-proclaimed splendor, and grin, in the light of new genetic findings that, indeed, Ernie’s rubber duck-Y had managed to float through about 300 million years of evolution not because of any complex machinery but mainly because it had too much air.

The Nature publication entitled The DNA sequence of the human X chromosome and published last March 17 is part of the sequencing of the Human Genome. It has concluded that the X chromosome, which has 1,098 genes, compared to the 78 of the Y, contains a lot more information about the health and disease of humans. This is significant in two main areas. First, it seems to be good news for females who bear two X chromosomes since any error on one X, could elicit help from the other X, which until now, was thought to be completely "silent" in females. The problem with males, being XY, is that with only one X chromosome, any error could not reach out for help since the other chromosome is Y, which mainly contains genes for reproduction and not so much genes for other nuances for life. Thus, the X genes that code for diseases, the scientists think, have more chances of being expressed in males, saying "a disproportionately large number of disease conditions have been associated with the X chromosome because the phenotypic consequence of a recessive mutation is revealed directly in males for any gene that has no active counterpart on the Y chromosome." I cannot help my fascination at this since genetics has also found out, a couple of years back, that a receptor in the X chromosome needs to say "yes" to the hormone in the Y chromosome, to make the sex of a baby "male." If the X chromosome stays silent on the matter, the baby could bear the XY chromosome but be female – yes, female – with mostly a female body but incapable of reproduction. Known as AIS (Androgen Insensitivity Syndrome), it is a rare condition but proof that genetically, the X is really the switch that holds the main fuses for life. Second, the X is not only rich and more varied but its other "X" in females, turned out to be not completely "silent" at all. In fact, it "speaks" to the active "X" in varying degrees in different women, according to studies probing the silent Xs of different women. So not only do females hold the main genetic switch, it seems to also have a customer-friendly next door "service-repair" facility in the supposedly silent "X."

So is it genetic doom again for the puny Y? To save you from what some say are my all too hasty judgments to metaphorically exile Ys when findings like these surface from the annals of science, here is what the journal said in scientific language: "A detailed comparison of the human X and Y chromosome sequences reveals the extent of Y chromosome decay in non-recombining regions." Decay. Depressing huh? Now, this XX would like to extend a sympathetic hand to the rubber duck-Y and would just like to call it "drift."

But wait. The Achilles of the Y genetic studies, David Page, says the Y does not need a helping hand from XX because the Y chromosome figured out a way to keep itself from decaying or drifting into oblivion. Page is a geneticist who has been reported to sport a coffee mug with the inscription "Save the Men," and has been scrounging the Y genetic stretch for what seems to be a scarce genetic commodity: the heroics of the Y chromosome. And whola! He and his colleagues found out in 2003 and published in Nature in June of that year, one significant battle strategy that the Y uses to save itself. Well, it just does that: it "saves" itself. It keeps "back-up" copies of itself in palindromes (words that remain the same spelled backwards). This means it keeps copies of its genetic "Madam, I’m Adam" codes tucked somewhere in the pockets of the Y cargo pants, so that as long as it remembers how to spell backwards, it will get itself back together again. I don’t know about you but there is something eerie as well as comical about the Y chromosome having no option but to "talk to itself" in palindromes in order to keep itself in the evolutionary race. Imagine, this could explain why women, after ages of trying to flake for men, layer by layer, into morsels that Y could manage to chew, pictures of situations both sexes are confronted with in all of human history, as they lived from caves to townhouses, uniformly and consistently, throughout history, get only one palindrome-response from men: "Huh?" 

"Huh?" – a lonely vowel sandwiched between the same consonant. This is the all-too familiar response we women get after asking our men on all kinds of issues sandwiched within at least 40,000 years of human civilization. A favorite Y of mine retorted to this observation of mine by saying, "Simplicity and economy are virtues." If we are talking about financial resource management, that may be true, but genetically, unless you are a fruit fly or a worm, these so-called virtues are a let-down. But don’t worry fellows, in the same Nature journal article entitled "Abundant gene conversion between arms of palindromes in human and ape Y chromosomes," Page et al. found you are in good ancestral company as the same palindrome strategy was found in male chimpanzees. I wonder if all that head-scratching I see in chimps is their version of "huh?" An evolutionary conference of palindrome strategists is really a bit too indulgent for my taste even for my most detached contemplations.

Last January, New York Times columnist Maureen Dowd had fun in her piece "Men Just Want Mommy" interpreting studies done in the US and Britain that month that revealed that men are more likely to marry women who are "inferior" to them, measured in terms of career placement. The British studies also found that the higher a woman’s IQ is, the less her chances of marrying, while it is the reverse for men. I cannot help but wonder if these findings at all find some genetic basis in the Y having no new material to re-invent itself to adapt to the complexities of the XXs and the environment, that men still generally want the same thing over and over again in their women regardless of what evolving women have become.

So I guess we are back to the high and open evolutionary seas where we find rubber duck-Y, going at it with his back-up copies of itself, and the Victoria, endowed with pregnant coded treasures of intimate genetic biographies. In the earliest Olympics in Greece, exclusive only to males, when women, out of their curiosity, were found sneaking in the vicinity, they were promptly hurled off the cliffs into the raging seas. Now, genetic science has shrunk and lightened the historically burdensome Y that I can now scoop it in my mind’s eye and walk to the nearest precipice and….! Uhm, nah, will let the Y dangle for a while in the breeze while I enjoy the view.

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