The Y chromosome contains vital genes, for males, that code for things males need. Its really pretty much that. Take away the Y chromosome and most mammal species aren't going to survive. Even the rats that lost it had the equivalent genes on the X chromosome. The gene expression of females isn't the same as males in short. In spite of the fact that females and males share an X chromosome.
Some (maybe most) of the genes in the Y are only useful for men. Others of the genes in the Y chromosome are “vital”, but the X chromosome has a copy of them. So the men have two copies of these parts.
In women, one of the X chromosomes is inactivated, so it’s almost like that each cell has only one (active) X chromosome. The shared part is not inactivated. So both men and women have two active copies of these parts, and only one active copy of the not shared parts.
The Y chromosome doesn't contain vital genes, in fact by chromosome standards it doesn't contain many genes at all. The primary role of the Y chromosome is as an activator and modifier of gene programs that reside all over the genome. This makes sense because the male anatomy is mostly just a modification on top of female anatomy (preventing some growth here, promoting some other growth there... done).
That said, I don't think it's possible to create a fully fertile male by forgoing the chromosome and just giving hormones - there might be some very few sex-specific proteins on it, but I think it depends on the species.
That's what I thought but then the article says this:
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The Y has been stable for the past 25 million years, scientists say. And a major reason is that many of its remaining genes are crucial to the survival of all humans, going far beyond sex determination. There are genes that affect protein synthesis, how active a gene is, and others that splice RNA segments together. They are found in the heart, the blood, the lungs, and other tissues throughout the body. “These are powerful players in the central command room of cells,” says David Page
I guess it depends a bit on what genetic regions we're talking about but to my knowledge since the Y contains so few genes it's not surprising that almost none of them changed for a long time. It's already very stripped-down. I'm far less sure about non-coding regions though, I'd have to check up on that.
From what I can tell the text doesn't contain a lot of new or surprising information, but it does present it in a misleading way.
It's clear that sexual dimorphism in humans is profound in some respects and superficial in others. Since the Y chromosome regulates sexual development, and since males do get some metabolic modifications, saying the Y influences protein synthesis in vital tissues is mostly a truism.
Saying that for example autoimmune diseases with lopsided sex distributions are not connected to sex determination is a fruitless semantics game disconnected from the actual science. To be fair, it's not any more sensationalist than the "rotting Y chromosome" spiel which has been in the press earlier, but all of this is really more a testament to all the things that are wrong with science reporting (and the scientists who enable it) than anything else.
Well that's the question - if it's "crucial to the survival", then how do ~50% of all humans survive without it?
The article does makes a point that unimportant genes have been eliminated from the Y. However, if the remaining genes and relevant proteins are beneficial (as opposed to mandatory), then it would still make sense in the [very] long run that those genes would migrate to some other chromosome, be beneficial also for female homo sapiens, and then get eliminated out of the Y as redundant there (since they'd be somewhere else for both genders already)
The Y chromosome contains vital genes, for males, that code for things males need. Its really pretty much that. Take away the Y chromosome and most mammal species aren't going to survive. Even the rats that lost it had the equivalent genes on the X chromosome. The gene expression of females isn't the same as males in short. In spite of the fact that females and males share an X chromosome.