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X Chromosome May Leave a Mark On Male Fertility 124

Posted by samzenpus
from the guiding-hand dept.
sciencehabit writes "Behind every great man, the saying goes, there's a great woman. And behind every sperm, there may be an X chromosome gene. In humans, the Y chromosome makes men, men, or so researchers have thought: It contains genes that are responsible for sex determination, male development, and male fertility. But now a team has discovered that X—'the female chromosome'—could also play a significant role in maleness. It contains scores of genes that are active only in tissue destined to become sperm. The finding shakes up our ideas about how sex chromosomes influence gender and also suggests that at least some parts of the X chromosome are playing an unexpectedly dynamic role in evolution."
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X Chromosome May Leave a Mark On Male Fertility

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  • ...women! Excellent news for crossdressers. Bad news for religious fundamentalists of the middle east *wink* *wink*.
    • Re:So we are part... (Score:5, Interesting)

      by Samantha Wright (1324923) on Monday July 22, 2013 @02:46PM (#44353547) Homepage Journal

      No, it's just bad science journalism. The X chromosome is, for the most part, just another part of the genome; it contains all sorts of random junk, like blood clotting factors and parts of the receptors in our eyes that let us see colour. Any disease you've ever heard of that's "X-linked" or more common in men than women is either affected or effected, directly or indirectly, by the X chromosome. It is of no significance or note whatsoever that it contains stuff that's only activated in the male body.

      If you want something weird and sex-linked to rant insanely about, however, there's always the mystery of digit ratio [wikipedia.org].

      • It's significant from a health and evolutionary perspective. X inactivation in women makes expression of these genes mosaic which can prevent disease as well as cause some interesting immune responses. A gene can be beneficial in a pair but fatal solo which creates an interesting evolutionary tradeoff. If a woman can't have sons, is that a significant evolutionary disadvantage?
        • It's not a trait that lasts very long; every successive daughter has a 50% chance of passing it on afterwards, after all, so at most you'd expect such a mutation to only be around for three or four generations.

          However, such diseases are probably the reason why women make up 51% of the population. In the stereotypical portrayal of hunter-gather societies, certainly it is desirable to have slightly more women than men; the traditional division of responsibilities leaves the women with more consistent work. Co

      • X linked diseases are more serious to men because men can't be carriers. Men only get one X chrome and if it stinks we are stuck with it. It really isn't that shocking that a simplistic models used in genetics is proven wrong. That has been the common fact for the past decade.
        • by Samantha Wright (1324923) on Tuesday July 23, 2013 @03:28AM (#44358879) Homepage Journal

          There's nothing wrong here; it's just a simple misunderstanding by the journalist. We've known about X-linked for as long we've known about sex chromosomes, which inherently implies that the X chromosome has responsibilities beyond determining sex.

          Believe it or not, however, there are actually advantages to the Y chromosome being so minimal. Men are nature's beta testers: sometimes mutations in the X chromosome have significant benefits, and as these traits aren't balanced out by a second allele, they become more pronounced and hence are easier to detect during sexual and natural selection. This is (probably) why men display a greater variance in height, strength, and analytical skill. Similarly, by always suffering from a disease, and hence by not getting laid, men protect the rest of the tribe from the disorders they end up with. (Admittedly not great when you're actually in the middle of things, but sexual dimorphism and reproduction are both full of cruelties.)

  • by Anonymous Coward on Monday July 22, 2013 @02:26PM (#44353347)

    This is what happens when you have 3.5 Billion years of hacks. Legacy code, no overall architecture and absolute chaos.

    Let's start over and redesign humans from the ground up.

    • by etash (1907284)
      Agreed! But this time let's make it a truly intelligent* design, shall we?

      *no appendix for example.
      • by kaliann (1316559)

        The appendix may not be as useless as we once thought.
        Recent investigations have suggested that the appendix acts as a kind of "wildlife preserve" for our gut microbes. Throughout much of our evolutionary history (and much of the modern world) massive diarrhea has been a disease with two distinct issues: the likelihood of death from dehydration, and the disruption of intestinal flora in the survivors. A rapid recolonization with "good bugs" would have helped keep survivors from the kinds of recurring and

    • by Samantha Wright (1324923) on Monday July 22, 2013 @03:00PM (#44353699) Homepage Journal

      The Y chromosome used to just be a variant of the X chromosome, with only a few genes different; they were the same size. Over time, careless maintenance staff decided the backups were redundant and stopped keeping them. Thus something like 5% of men have one or more factory defects—most commonly colour-deficient vision, which some backward engineer decided was a feature [straightdope.com], not a bug, and went to great lengths to distribute bad copies to other users.

      On the plus side, we recently found out that the genome actually does have some [wikipedia.org] documentation—well, more like debugger symbols—so it's getting easier to figure out where the important binaries are located. Unfortunately in the process we also discovered that what appeared to be severe filesystem fragmentation is actually rotational performance optimization, and most of the rest of the disk is actually a messy broth of shell scripts [wikipedia.org], not merely unallocated space as we assumed [wikipedia.org].

      The sad thing is that even if we did redesign everything, it would probably be way worse than the existing codebase, particularly since we only have a tiny portion of the actual spec, which you can imagine was never exactly written down.

      • Can you explain that again, but with more car analogies?

        • Not a chance. The computing mapping is almost 1:1, and I simply don't know enough about cars to come up with a plausible explanation for the second half. Not everything in biology can be fit into a car analogy. Computers are somewhat easier.
      • by ildon (413912)

        This is what happens when you use genetic algorithms [slashdot.org] to design your code. It's a lot faster and more efficient, but no one knows how the hell (or even why) it works, and you end up with a bunch of garbage code that probably does nothing, but heaven help you if you try to remove it.

        • Well, we upgraded [wikipedia.org] to include a dynamic self-modifying portion, but there are some bugs; the basic self/non-self discrimination regularizer has a high tendency to cause wars over stupid things like who [ou.edu] has [turnbacktogod.com] the [blogspot.com] better [biography.com] facial [blogspot.com] hair [wikimedia.org]. Unfortunately, the wide range of other regularizers—emotions, convictions, self-preservation, altruism, and the rest—aren't enough to completely repress this sort of thing. On the plus side they're now inventing new ones [wikipedia.org].

          (In all seriousness, I think comparing the human s

      • I wish to table the motion that Samantha Wright be officially recognised as a Slashdot Treasure.

        That is all.

        • I think the Slashdot Treasury is already full of stale copypasta and mangled attempts at Yakov Smirnoff jokes, but the thought is appreciated.
    • It should have a consistent interface on phones and tablets as well.
    • by Alsee (515537)

      Let's start over and redesign humans from the ground up.

      Humans designed by committee might have cupholders for ears and camel humps, but even a committee wouldn't do anything as asinine as running a sewer line out through the middle of male&female sex bits.

      -

      • by Dcnjoe60 (682885)

        Let's start over and redesign humans from the ground up.

        Humans designed by committee might have cupholders for ears and camel humps, but even a committee wouldn't do anything as asinine as running a sewer line out through the middle of male&female sex bits.

        -

        Actually, only males have the sewer line run out through their actual sex bits. With females, the uterus and fallopian tubes are totally separate from the ureter. For the male, it makes a lot of sense actually. Why build two hoses when you can have one with a valve to select what comes out of it. Kind of like the hose on the gas pump at the filing station. One hose supplying different fluids as the situation warrants.

        As any engineering student will tell you, the purpose of engineering isn't to build the s

        • by twosat (1414337)

          Three graduate engineers were discussing who might have been responsible for the design of the human body.

          The first one said "Think of all the joints etc. it must have been a mechanical engineer".

          The second one said "No no, what about all the electrical impulses and nerves etc? It must have been an electrical engineer".

          The third graduate was shaking his head, "You are both wrong, the human body was designed by a civil engineer - who else would run a waste pipe through a recreational area"?

    • by kick6 (1081615)

      This is what happens when you have 3.5 Billion years of hacks. Legacy code, no overall architecture and absolute chaos.

      Let's start over and redesign humans from the ground up.

      The early programmers attempted to select the most fit patches (based on what they were able to observe as rank novice coders) to incorporate into the next version of the software. However, with programming techniques such as "fat acceptance," "gender nonconformity," and "child-bearing as a right" the most recent patches have absolutely ZERO quality control.

  • by Anonymous Coward

    And where's the documentation?

    • by MozeeToby (1163751) on Monday July 22, 2013 @02:32PM (#44353425)

      An infinite number of monkeys and a ruthless unit testing process. As for documentation, there's lots of people working on it, but some of them think they should be able to hold exclusive rights to their documentation.

      • by Nemyst (1383049)
        It's open source with unclear licensing, it's got no comments whatsoever and there's more dead code than you can shake a stick at. Sounds like your average SourceForge project then :)
    • "Source code is the ultimate documentation".

    • "The finding shakes up our ideas about how sex chromosomes influence gender and also suggests that at least some parts of the X chromosome are playing an unexpectedly dynamic role in evolution."

      Huh? What? Shakes up WHOSE ideas? Certainly not mine.

      YY babies don't tend to go very far (not XYY, just YY).

      Seriously... I don't see how this perfectly obvious stuff "shakes up" much of anything.

      • by Dcnjoe60 (682885)

        "The finding shakes up our ideas about how sex chromosomes influence gender and also suggests that at least some parts of the X chromosome are playing an unexpectedly dynamic role in evolution."

        Huh? What? Shakes up WHOSE ideas? Certainly not mine.

        YY babies don't tend to go very far (not XYY, just YY).

        Seriously... I don't see how this perfectly obvious stuff "shakes up" much of anything.

        Well, if they just reported the findings without adding hyperbole, nobody would read their article. For example take these two hypothetical titles: "Research sheds new light into inter-relationship between X and Y chromosomes." and "X Chromosome findings change how we will forever view gender." Which one do you thing will garner more page hits and readers?

        • I don't doubt that they might have had reasons to write it that way... but that doesn't do any more to impress me. The uncalled-for sensationalism actually ends up giving me a negative impression.
  • by i kan reed (749298) on Monday July 22, 2013 @02:31PM (#44353407) Homepage Journal

    The y chromosome doesn't code many genes at all, and this has been known for a long time. It's main function is turning specific genes off. Anatomy of all sorts, including gender characteristics is coded across all 24 chromosomes. The y just suppresses the female parts.

    If I learn something over a decade ago in a high school class, it shouldn't be "science news."

    • by Teresita (982888)
      The Y chromosome is a li'l runt and they think it won't even be there anymore in a hunnert thousand years or so.
      • by Valdrax (32670) on Monday July 22, 2013 @03:16PM (#44353889)

        The Y chromosome is a li'l runt and they think it won't even be there anymore in a hunnert thousand years or so.

        I don't think there's anyone who takes this seriously any more. There were some people suggesting that if genes are lost at a linear rate off the Y chromosome, it should disappear in another 10 million years. However, chimpanzees and humans show no difference in the number of genes on the Y chromosome since we diverged 6-7 million years ago, and we've both only lost one gene since we diverged from the rhesus macaque 25 mya. Given that sequencing of the platypus genome puts the common mammalian Y chromosome at a max of age of 166 mya, this suggests the linear model is just wrong.

        The Wikipedia has good article on this from which I drew my numbers, if you're interested in more.

        • Yeah... I heard this a few decades ago in grade school and I thought "WTF? Just about every organism on earth has two genders including things like plants. How can they say that the Y chromosome is going away?"

          Unfortunately, my WTF moments concerning these "scientific conclusions" haven't stopped. It's only gotten more frequent as I've matured. At least the poles haven't flipped like my "WTF sensor" for politics. I only go "WTF!?" when I hear something that actually makes sense in politics because I'm

          • by Valdrax (32670) on Monday July 22, 2013 @06:11PM (#44355545)

            Yeah... I heard this a few decades ago in grade school and I thought "WTF? Just about every organism on earth has two genders including things like plants. How can they say that the Y chromosome is going away?"

            To be fair, the Y-chromosome isn't the only way of determining gender, and the Y-chromosome of non-mammalian species has no common ancestor to those of mammals (they all degenerated long after splitting off).

            Some species use the number of X chromosomes. Reptiles and avians use ZW chromosomes, where the "female chromosome" is the shorter, degenerate one. Ants and bees are just kind of weird. [wikipedia.org] The platypus has something like 10 sex chromosomes and lacks the SRY gene, so we have no idea how it really works AFAIK, and platyfish (unrelated) have some sort of weird W/X/Y system.

            Single gender in plants is relatively rare, and I have no idea how it works.

            Unfortunately, my WTF moments concerning these "scientific conclusions" haven't stopped. It's only gotten more frequent as I've matured.

            I think that's more of a problem with bad science journalism than bad science, though.

            • To be fair, the Y-chromosome isn't the only way of determining gender

              Huh. Shows how much biology I forgot and / or didn't know about. Thank you.

              I think that's more of a problem with bad science journalism than bad science, though.

              Yes, you're absolutely correct, and I'll certainly concede that point. Despite that: in my personal view of the world, I still consider science journalism to be part of science. After all, without a good way to spread truth to the masses, can science really be considered science? (I suppose it's fair to say that too many people who believe in the whole earth-created-in-six-day-and-here's-scientific-proof has shaped this particul

      • by Darinbob (1142669)

        If you look at all the chromosomes though, there are a lot of "runts". The size of the chromosome doesn't matter as long as they can hold a few genes that are vital.

    • Re: (Score:2, Flamebait)

      The y just suppresses the female parts.

      So the suppression of females by the Y Chromosome is natural, and this is what evolution has intended and achieved, and the general oppression of the women in the society is just a natural extension of what is going on in cellular level. So all the male chauvinistic pigs can now breath a sigh of relief, "we can't help it. we are born this way".

    • by wierd_w (1375923)

      Actually, it does both: Turn genes on, and turn genes off.

      Take for instance, "TDF Males".

      (TDF == Testis Determining Factor, and is encoded by the SRY gene on the Y chromosome)

      This single gene is sometimes translocated to the X chromosome in a rare mishap of cellular meiosis during gamete production.

      http://en.wikipedia.org/wiki/XX_male_syndrome [wikipedia.org]

      Since this is just a single gene out of the many on the Y chromosome, resulting phenotypical male offspring are infertile, and the "androgenization" of the offspring i

    • Yes. Exactly. Exactly. Exactly.
    • by gr8_phk (621180)
      The Y chromosome has degenerated because it is only present in males. Therefore it does not benefit from crossover. Therefore a bad mutation on it is passed down to all generations of males from that point on. This makes it a very poor place to put useful genes, and it is gradually becoming nothing more than a device to determine gender.
  • Behind every great man, the saying goes, there's a great woman

    Behing every failed man, there is a failed woman.

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      Behind every running man, there is a woman with an axe.

  • by goffster (1104287) on Monday July 22, 2013 @02:51PM (#44353601)

    Otherwise there would be very little genetic diversity between father and
    son regarding fertility, and we know that to be false.

    • Otherwise there would be very little genetic diversity between father and son regarding fertility, and we know that to be false.

      Not necessarily; the determining factors in fertility could just as easily be on the autosomal chromosomes (the of which nearly everyone gets one copy from each parent, and aren't involved in sex determination). Given that these chromosomes make up most of our genomes, in fact, you'd kind of expect that.

  • by Anonymous Coward

    Women, X-X. Men, X-Y. Chuck Norris, Y-Y.

    There is no chick in Chuck Norris.

  • Can't live with em, can't live without em.
  • by kilodelta (843627) on Monday July 22, 2013 @04:24PM (#44354621) Homepage
    That the basic body plan is female to start with. I mean why else would men have nipples too?

    And look at differences in the reproductive organs of men and women. Testes and Ovaries - just small deviations create each, and of course location.
    • Pacifiers. Although, men do actually lactate, they just can't produce very much.
    • "God isn't interested in technology. He knows nothing of the potential of the microchip or the silicon revolution. Look how he spends his time! Forty three species of parrot! Nipples for men! Slugs! He created slugs! They can't hear! They can't speak! They can't operate machinery! I mean, are we not in the hands of a lunatic? If I were creating a world, I wouldn't mess about with butterflies and daffodils. I would have started with lasers, eight o'clock, Day One!"

      -- Evil, "Time Bandits"

  • This is nothing new. The Y-Chromosome is too small to actually code for anything, and no one ever thought that it could contain more than a handful of genes. The Y is just a set of GOTOs pointing to the X.
  • by Rob_Bryerton (606093) on Monday July 22, 2013 @05:05PM (#44355031) Homepage
    You didn't finish that saying. Time to burn some karma.

    "Behind every great man, the saying goes, there's a great woman.

    And behind every great woman, there's a man. Staring at her ass.

  • Actually not, but he did write this pun filled song - to the tune of "Home on the Range,"

    Oh, give me a clone
    Of my own flesh and bone
    With its Y-chromosome changed to X
    And when it is grown
    Then my own little clone
    Will be of the opposite sex.

    More if you search for it.

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