X Chromosome May Leave a Mark On Male Fertility

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."

Comments

3.5 Billion years of hacks

[Anonymous Coward]

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.

Re:3.5 Billion years of hacks

[Samantha Wright]

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 , 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 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, not merely unallocated space as we assumed.

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.

Moronic writer. Old news with new data.

[i kan reed]

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."

Re:Who wrote this mess?

[MozeeToby]

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.

Re:So we are part...

[Samantha Wright]

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.

Y chromosome is likely to stick around.

[Valdrax]

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.