X Inactivation 

I remember watching your videos in AP Bio back in high school! Now I'm in medical school reviewing certain concepts and here you are to the rescue. Thank you for the great content!

I am taking Genetics in college and got very confused with X inactivation. Thank you so much for clearing all of the blur!!!

This video makes me want to get a bunch of cats and study their genetics.

This is too interesting, I'm currently reading about this for school, so watching a lot of stuff like this is so helpfully

Mr. Paul Anderson is the best teacher I’ve ever come across. He always doesn’t fail to impress us.❤

thanks for this. I’m a vet med student and the reading my course provided is so wordy and difficult to grasp. You explained it in a way that I can actually understand.

This video actually helped me understand a bit more about what X inactivation meant and how genetic information is distributed in the stem cells, which is a theme we're seeing right now in my career. So I want to thank both Paul Andersen and the teacher who recommended this video to our class.

You explained this concept perfectly. Thank you for bringing the up the very important distinction of this X chromosome inactivation mechanism which is the random inactivation of the X chromosome occurring in each cell.

Thank you so much! This is much better than lectures. 👍👍 Greentings from a medical student based in Tunisia 👋🏻👋🏻👋🏻👋🏻

This man has never steered me wrong...shout out to Professor Andersen

This video is pretty old, but still appreciated! It helped me understand my own cats. Thanks!

You're an AMAZING teacher!! I'm revising the subject and didn't understand much about this. THANK YOU GOOD SIR!!!

Wow, you explained this concept so well Mr. Anderson. Thank you so much! P.S - I think it'd be really cool if you made a video on Polyphasic sleep (which ties in with circadian rythms)

You're saving my ass in Bio! Thank you so much, sir!

Thank you Mr. Andersen!

This was really great - so useful in helping me understand the concept in a quick and simple way. Thank you so much!

MY REPORT FOR TOMORROW MAINLY CONSIST OF BARR BODIES AND I FIND IT HARD TO UNDERSTAND BUT THEN I CAM ACROSS YOUR VIDEO...I JUST WANNA THANK YOU BIG TIME!

dude you are awesome!! your videos always help me with homework or exams!!!

Genetic Midterm tomorrow! This made more sense than my lecture notes! Thank you.

Lol these videos are even amazing for college genetics, I’ve watched your videos since 9th grade. When I finally get to med school I owe you

WOW talk about clarity and simplicity Thank you so much!!

All ur video are old but gold

Hi! awesome video really explained X-inactivation super well, but I have a pressing question: How does X-inactivation relate to X-linked dominant / recessive traits? more specifically: In X-linked dominant inheritance (in females), a single dominant allele (heterozygous) can cause the trait, just the same as a pair of dominant alleles (homozygous dominant) would, while the lack of any dominant alleles and thus a pair of recessive alleles (homozygous recessive) results in no expression of the trait. A heterozygote (female) should present with the trait since the dominant allele dominates over the recessive one for expression, and in pedigrees the female is shown to be affected just the same as a homozygote, however, when taking X-inactivation into account, really isn't the heterozygote expressing the trait about 50% less, since half of the female's cells are expressing the dominant allele while the rest are expressing the recessive allele which expresses a different phenotype? That being said, both are still expressing the trait, unlike in X-linked recessive inheritance (in females), where a heterozygote is NOT considered to be affected, and is not shaded in pedigrees, because the dominant allele which doesn't code for the trait in question dominates over the recessive allele of the condition, but when taking X-inactivation into consideration, the heterozygote should express the dominant allele in half the cells and the recessive allele in the rest, a single recessive allele in the absence of a dominant allele is enough for a trait to be expressed like in males, so really, the heterozygotes of both patterns are exactly the same, they both express both alleles equally, why is one said to be affected while the other is not (also one is shaded the other not)?

I am studying Barr bodies and what neutrophils have to do with them,,, thank you for such an illustration.

This guy is awesome

Thats is amazing! Showing basics in such way! Thank you!

That’s amazing! I’ve never noticed that about cat’s fur !

Thank you. Calico cats confused me. I like the extensions at the end. Cool facts.

It is my understanding that there may be more male calico and tortoiseshell cat embryos, but, because of the chromosomal defect, they usually die in the womb. I volunteer at a feral cat clinic. Over the past 20 years we have spayed and neutered over 125,000 cats (I live in Henderson, outside of Las Vegas). During that time we have never seen a male calico or tortoiseshell cat. I will add, however, that I adopted a male tortoiseshell cat, Nacho, 14 years ago.

You saved me, dude. You're a great teacher.

This was definitely helpful! Mr. Andersen, you are a great teacher! Thank you for sharing to educate others :-D

You are a life saver

Mary Lyon is a total queen

Barr Bodies are not disintegrated X chromosomes; they are highly compacted X chromosomes in an inactive state. They can't be degraded, the cell needs all the X chromosomes intact such that it can go through replication (S phase) and pair up at the metaphase plate.

Thank you! Love the fact that you make it easy for us to understand and how you break it down for us! :) thank you soooo much!!!

Hey,thanks alot.ur explanation is just awesome.

Excellent explanation sir!

The man carries all chromosomes (X and Y). The woman only carries the X chromosomes. The man who has the X and Y chromosome carries the direct bloodline from both parents, meanwhile the female only carries her mother's X chromosome. New studies shows that the Y chromosome can be traced much more accurately than the X.

Great Explanations!

It was certainly helpful :D This is really going to help me through my genetics exam! Thank you so much!

That helped me a lot. Thank you

The only video on the topic not narrated by a person with a thick Indian accent. ;) Great video though.

Thanks for this video now I understand much better the processus

Thank you so much this was sooo helpful for me!

Very well explained. Thank you!

Best explanation ever!!!

thanq sir....understood clearly...!!

SUPER helpful. Thank you!!!

Thank you from USC!!!

God bless you man. I just watched your video on chromosomal genetics and I'm thinking you dont have a video on this and come to find out you do ! your so awesome lol

Greatly explained!!

Nicely explained thanks!

Very clear video!

Nice explanation. Thanks.

wonderful video, thanks very much!! that was so interesting!

Does the Barr Body slide is flipped? The dense one should be the Xi and the spread one is Xa

Some teacher in an American uni was fired to provide this class. 4 students complained and after that he was fired.

incredible explanation !! Thanks a lot sir..

I can watch this dude talk forever

beautifully explained!

BIG HELLO FROM IRAQ

Thank you!

What is the difference between x- inactivation and codominance?

Great video. Thanks

Is this also the same as when some people have different skin colors on their body? Or is that epistasis as well?

Great video

Thanks for the great video!

thanks for this video

this is really helpful!!! thanks!!!

Omg That mouse freaked me out I have phobia on it haha but good video! It helped😊

Professor,What's the meaning of "wad up" that you mentioned in the video?

Thanks so much... :D

This is magnificent 😍😍😍

I love you Bozeman science

This was great BUT what I need to know is the Xic (genes xist and tsix) and the epigenetic regulation by Long Noncoding RNAs, please? An animation for that? =)

really useful~ thank you so much

AMAZING!!!

Thank you! now is clear....

great!!

you, sir are a legend. :) thank you!

that was great! thanks

awesome!

Wow it helps me a lot! Thx :)

Wow 😳 thank you man

Is this phenomenon true for all animals that have patches over their skin (eg- cows, horses etc?) or just for cats ?

thanks a lot

How do the cats reproduce when it is very rare to find a their male counterpart?

So why is colorblindness so much more in common in females than in males if one of the X chromosomes randomly becomes a Barr body?

thank you sir

esto es asombroso

you are awesome!!!!

Thanks man!

Good that your talking about cats, you said... "before your born..." if you're a female... Cause every human share the same course, they all are XX for the 7-8 weeks of their lives! Because, even if you're a male, ur 1st 7-8 weeks, u are a female! I pretty much imagined that it was the same 4 cats?!?!

we are in the matrix!

Pretty good stuff..

thanks!!

is it possible for the barr body to be sequenced? or only the activated x that can only undergo DNA sequencing?

not an expert on this - but I assume for tigers it's perhaps not an X-linked characteristic, therefore no lyonization would have to take place as they would have 2 copies? :) Would be interesting to look at evolution wise, why the cat's pigmentation moved onto the X chromosome...

very cute KITTY HE PICKED

x inactivation is something like codominance ? because the two phenotypes are express?