28 April, 2012

A-Z Blogging Challenge: Y Chromosome

The Y chromosome.
Public domain image.
The Y chromosome is one of two human sex-linked chromosomes.

To partly continue yesterday's post about the X chromosome (though reading that one isn't absolutely necessary, in case you're wondering), the Y chromosome, unlike the X chromosome, is associated with males, since males are XY and females are XX. The Y chromosome has around 58 million DNA base pairs (opposed to the X's 155 million), 70-200 genes, and makes up about 2% of all DNA.

95% of the Y chromosome is male-specific, although sections called the pseudoautosomal regions have identical counterparts on the X chromosome. Because of this, only pseudoautosomal regions can exchange places in a process called recombination (which occurs between all of the two X chromosomes in females) and male offspring possess an almost identical copy of their father's Y chromosome.

Conditions that can result from changes in the Y chromosome include 48,XXYY syndrome (where there is both an extra X and an extra Y chromosome in males) and 47,XYY syndrome (where there is the normal one X chromosome, but two Y chromosomes).

A graphic example of 47,XYY syndrome, with a male on the left
and female on the right, by Silver Spoon and Lucas Zienius,
As I was researching this post, I also found that there was a good deal (as in, webpage after webpage) of speculation that men would start to die out, since the Y chromosome shrank from being identical in size to the X chromosome to its current state of having fewer than 10% of the number of genes on the X.

However, this is theory has been rather debunked by the finding that no Y chromosome genes have been lost for six million years, and that the Y chromosome evolves rapidly. So, it seems half of the human race is genetically safe. (The chances that humanity will survive for another six million years might be far off, anyway.)




I hope I've made this part of chromosomal biology interesting for you all. Though if not, I hope you'll come back on Monday anyway in which I address a topic that's easier and allows for some great (in my opinion, at least) photographs. ;)

And since it's the second-to-last day of the Challenge: Are you looking forward to slowing down on the blogging in May, or will you just miss it? I'm a bit of both . . .

-----The Golden Eagle


DeniseCovey_L_Aussie said...

Hey Golden, yes, I'm looking forward to that finishing line on Monday and getting back to a less frantic blogging lifestyle. I've really enjoyed your posts, and thank you for taking the time to visit some of my childhood bloggers.


Anonymous said...

Gimmie a Y...
ok... done

yeah, I am glad we didn't go through with the next REN3 for May. I need a break.

Hilary Melton-Butcher said...

Hi Golden Eagle - I enjoyed both your chromosome posts .. and am glad to read we're not in the process of dying out or losing half our population.

Interesting series .. cheers Hilary

Anonymous said...

So...men are more adaptable (read: able to evolve), at least on a primary level?

mshatch said...

I'll definitely be back and even if my brain hasn't been able to fully comprehend all your a-z posts, I've enjoyed every one I read - and I'll be back on Monday for the last :)

And no! I won't miss it! It was fun but I'm glad it's just once a year.

Cherie Reich said...

Sounds like good news for men. Mankind, not as much. LOL! :)

Tanya Reimer said...

This made me smile. What a fun way to look at our genetics!

Alex J. Cavanaugh said...

Better hope we don't die out or that will end the human race!

Rusty Webb said...

I've enjoyed all your posts. I'm more than ready to take some time off though. I'll be glad when the month is over.

Julie Musil said...

I don't want the Y to die out! What an interesting topic for Y day :)

Deepali said...

I can't wait to see your final post! :) CONGRATS on making it all the way and so perfectly regularly :)

Anonymous said...

Thought I would stop by since I haven't been on your blog in a while.

Biology! That is some exciting stuff. I am currently majoring in Biology/Pre-Med. I really enjoyed this post.

Christine Rains said...

Interesting posts. I don't think the human race will last that long either! I'm a bit sad the Challenge is going over. It's been fun, but I'll be glad to have some time back to get into a schedule of writing. I've been visiting too many blogs these past few weeks!

Lady Gwen said...

Hmmmm, another round of evolution anyone?

Inger said...

My sister had Down's Syndrome, but I didn't know there were so many other ways that there can be extra chromosomes that affect people born with them. Thanks for all this information. I'm so old I remember when they discovered DNA and I even read The Double Helix back then. Fascinating stuff. You are something else and I really admire you greatly.

Michael Offutt, Tebow Cult Initiate said...

Oh good. I'm glad that the Y Chromosome is safe. I enjoy looking at young men.

L.G.Smith said...

What Michael said applies to me too. :P

Also, I enjoyed your posts. Always so intelligently written. I learn so much here. And, too, I'm glad for things to be winding down. I think we all need a blog break after this marathon month.

Have a great weekend!

Pat Hatt said...

I don't think we'll still be here in 6 million years, but it's nice to now it was bunk. And the cat will still post every single day, as always at his bay.

Susan Gourley/Kelley said...

Since I have five sons and hope to have grandsons someday, glad to hear the males will still be around. I am looking forward to blogging only three or four times per week.

Matt said...

Haha awesome its the male chromosome. Kind of makes sense if you look at the letter Y and X. Maybe I'm just being childish. Awesome info as usual though, keep it up!

Carol Riggs said...

How can you be a writer (very right brained) and yet elaborate on all this very left brained stuff? LOL Good job. I didn't realize there were so many chromosome combinations, with extra X's and Y's!

cleemckenzie said...

Here's to balance. That might help the human race survive into the distant future. Great Y-day post.

Andrew Leon said...

When I was a kid, Y was my favorite letter.
Yeah, I know that that doesn't exactly go with your post. At least, not on the surface. In my mind, it does, though.

Adam said...

the best chromosome

Cheryl Klarich said...

To misquote Dorothy in Jerry Maguire... Y's are the enemy... but... I still love the enemy...

Paul Tobin said...

You are going full steam ahead on this challenge. I am impressed.

Rachel Morgan said...

Yay! Stuff I know! Chromosomes have interested me since I first started learning about them in high school biology. Fascinating. Absolutely fascinating how those tiny little things control the majority of who/what we are!

Baur said...

This is really neat!

DWei said...

Oh phew, I heard about the first part of the y chromosome disappearing but not the part debunking that.

Quite reassuring.

Nas Dean said...

Interesting post on 'Y' chromosones.

KarenG said...

Too bad there's not a Z chromosome, and you'd be done.

The Golden Eagle said...

Denise: I'm glad you've enjoyed my posts! :)

You're welcome; it's been a great series!

Stuart: Wait, REN3 isn't happening in May? Oh . . . that was a surprise, since I didn't catch it'd been cancelled. I can see why, since all of the original hosts are participating in the A-Z Challenge!

Hilary: LOL. I am, too.

Joshua: I'm not sure. I don't believe I came across any articles stating that, but it's possible.

Mshatch: Thank you for returning to read my posts!

Me, too. I'd burn out if I had to blog A-Z for more than one month.

Cherie: Ha! Bet there are some who would disagree with you there. ;)

Tanya: I'm glad it make you smile. :)

Alex: It certainly would . . . and that would be really sad.

Rusty: Thanks.

Same here!

Julie: Good to hear you found it interesting. :)

Deepali: Thank you! Much of that was due to scheduling posts; all I had to do for most of the month was sit back and watch them go up. And reply to comments, of course. :P

Jeremy: Thanks for coming by!

I love learning about biology.

Glad you liked it!

Christine: I hope to start writing more in May as well. I really, really haven't been doing enough.

Lady Gwen: Who knows . . . maybe. :)

Inger: There are definitely a lot of them.

You're very welcome!

Aw, thank you so much. I admire you as well; you seem like a truly interesting, kind person from your blog posts.

Michael: Yup. There are benefits of the Y.

L.G.: LOL. I think other commenters would agree with you two!

Thanks. :)

Hope you enjoyed your weekend!

Pat: You're a marathon blogger, all the time. I don't know how you do it. :P

The Golden Eagle said...

Susan: I don't have kids, but I have to say I'm a bit glad as well.

Me, too. Though there are a slew of events right at the beginning of May, so it looks like I'll be posting a lot for another week or so!

Matt: I don't think that's childish. Plenty of scientific terms and theories are based on visuals. :)

Carol: Thank you!

Multiple personality disorder. :P Just kidding!

I didn't, either, until I started really doing the research for these posts.

Cleemckenzie: Indeed.

Thank you!

Andrew: But it's an interesting fact, nonetheless.

Adam: Maybe. As a member of the all-X, I'd have to say they're about equal. ;)

Cheryl: LOL. Ys can be nice sometimes!

Paul: I wanted to post the best stuff I could for this Challenge--especially as science isn't a topic I usually take on at The Eagle's Aerial Perspective.

Rachel: It definitely is!

Baur: Agreed. :)

DWei: I'm sure it is. And I think it's comforting for everyone to know that humanity won't die out!

Nas: Thanks!

KarenG: LOL. Yup, it's too bad . . .

Craig Edwards said...

Great post!

Sharon K. Mayhew said...

WTG on accomplishing all the (almost) a-z posts.

Really interesting stuff!

College Speed said...

Cool post :) this is one of the most creative uses of Y i saw in the A-Z challenge participants

Lynda R Young said...

I'm relieved humanity will survive another 6mil years ;)

Noushka said...

Truly interesting and easy to understand the way you put it!
That said, I really would like to know one day what that "Junk DNA" is all about!
I do not believe it has been put there for no reason!!
When we unlock that secret, I bet we will be in for a huge surprise! !)
Let's see what you will show us today...!!
Thanks for your kind comments on my blog, it means a lots to me!!
Congratulations for your work and have a great week!

The Golden Eagle said...

Craig: Thank you!

Sharon: Thanks. :)

College Speed: I tried to go with the more unusual scientific subjects for the Challenge.

Lynda: LOL. Yeah, me too.

Noushka: Glad to hear I've made the subject clear!

They say that so-called "junk DNA" does serve a purpose in regulating protein activation/inactivation.

You're welcome; I always enjoy stopping by your blog and looking at the photographs!

M Pax said...

Y's are shrinking? Fascinating. Thanks for sharing your research, Eagle. It's really interesting.