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!
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.
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.
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.
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)
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!
@@hugodaniel8975 Well this was already for my bachelors at university haha. After that I did a masters in Biology, and now I work at a hospital at the Clinical Genetics department :) I don't really use this subject during my job though. I deal with deletions, mutations, etc in DNA
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)?
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.
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.
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
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.
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? =)
Why splotches of orange, splotches of black? If its truly random, there would be orange, white, and black tiny spots or hairs throughout the cats body. Can you explain why orange hairs group together, and black... it seems X-inactivation happens to a group of cells at a time (of the same allele), instead of single cells at a time... Can you explain?
I think I figured it out... to answer my own question, lets say 6 cells get replicated from the zygote, 4 of those get the X chromosome where orange is active, 2 get the X chromosome where black is active. All the daughter cells of these "initial 6 cells", will inherit the same X inactivation pattern. Thus, they appear in groups in the phenotype. What I don't get is how these two steps happen, if they happen at all...
Oops, yeah I meant to say males than females. But why is it more common in males then? Why are women only usually carriers since the X inactivation is random?
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...
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?!?!
Harmya Alderson Your'e not necessarily a "female" in first 7-8 weeks. sex determination occurs later, so female and male designation are both given later. Before this, when they are "identical" they are neither 'female' nor 'male', instead they just contain the same primitive structures that will eventually differentiate into a female system or a male system...check out some reproductive embryology lectures for visual clarification! they depict this concept accurately! And yes this is the same for cats too
Wrong... All embryos are female (human) the 1st 7-8 weeks. Sex determination only pop's up later for male... it's only after genes deterioration that it becomes a male! I'm always surprised to see how people are ignorant on the subject! ... or refusing to accept reality!
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!
Same here :) This guy carried me through AP Bio and is one of the biggest reasons why I got into medical school
I am taking Genetics in college and got very confused with X inactivation. Thank you so much for clearing all of the blur!!!
How's it go? I love genetics too!
This video makes me want to get a bunch of cats and study their genetics.
only the "get a bunch of cats" part for me lol
Mr. Paul Anderson is the best teacher I’ve ever come across. He always doesn’t fail to impress us.❤
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.
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.
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.
This is too interesting, I'm currently reading about this for school, so watching a lot of stuff like this is so helpfully
Thank you so much! This is much better than lectures. 👍👍
Greentings from a medical student based in Tunisia 👋🏻👋🏻👋🏻👋🏻
Greeting dear
Are you already a doctor
This man has never steered me wrong...shout out to Professor Andersen
You're an AMAZING teacher!! I'm revising the subject and didn't understand much about this. THANK YOU GOOD SIR!!!
X inactivated has been stumping me for a while but I get it know in only a couple minutes of your video that's so awesome!
This video is pretty old, but still appreciated! It helped me understand my own cats. Thanks!
This comment is pretty old, but still appreciated! It helped me understand my own cats. Thanks!
@@warpromo6636 This comment is pretty old, but still appreciated! It helped me understand my own dogs. Thanks!
@@warpromo6636 This comment is pretty old, but still appreciated! It helped me understand my own cats. Thanks!
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, 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)
dude you are awesome!! your videos always help me with homework or exams!!!
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!
Genetic Midterm tomorrow! This made more sense than my lecture notes! Thank you.
You saved me, dude. You're a great teacher.
This was really great - so useful in helping me understand the concept in a quick and simple way. Thank you so much!
Thank you. Calico cats confused me. I like the extensions at the end. Cool facts.
You're saving my ass in Bio!
Thank you so much, sir!
Thank you Mr. Andersen!
This was definitely helpful! Mr. Andersen, you are a great teacher! Thank you for sharing to educate others :-D
WOW talk about clarity and simplicity Thank you so much!!
Thats is amazing! Showing basics in such way! Thank you!
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!!!
It was certainly helpful :D This is really going to help me through my genetics exam! Thank you so much!
Good luck on your exam. Did you pass it😊
@@hugodaniel8975 Haha indeed I did, Now I work as a genetics analyst😂
@@Manoahmanolo wow i want to work on genetics too 😍 what did you study in college? Do you use x inactivation concepts at your job?
@@hugodaniel8975 Well this was already for my bachelors at university haha. After that I did a masters in Biology, and now I work at a hospital at the Clinical Genetics department :)
I don't really use this subject during my job though. I deal with deletions, mutations, etc in DNA
All ur video are old but gold
That’s amazing! I’ve never noticed that about cat’s fur !
This guy is awesome
For-fucking real!
Mary Lyon is a total queen
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.
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.
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.
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
The only video on the topic not narrated by a person with a thick Indian accent. ;) Great video though.
You are a life saver
Some teacher in an American uni was fired to provide this class. 4 students complained and after that he was fired.
That helped me a lot. Thank you
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.
Hey,thanks alot.ur explanation is just awesome.
Excellent explanation sir!
Best explanation ever!!!
Thank you so much this was sooo helpful for me!
Thanks for this video now I understand much better the processus
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?
thanq sir....understood clearly...!!
Very well explained. Thank you!
SUPER helpful. Thank you!!!
Omg That mouse freaked me out I have phobia on it haha but good video! It helped😊
Greatly explained!!
Thank you from USC!!!
Very clear video!
wonderful video, thanks very much!! that was so interesting!
incredible explanation !! Thanks a lot sir..
Does the Barr Body slide is flipped? The dense one should be the Xi and the spread one is Xa
Nicely explained thanks!
Nice explanation. Thanks.
Great Explanation!
beautifully explained!
Thank you!
Great video. Thanks
thanks for this video
I can watch this dude talk forever
BIG HELLO FROM IRAQ
you messed up the chromosomes, the inactive one is compacted and the active is spread
This is magnificent 😍😍😍
Great video
this is really helpful!!! thanks!!!
x inactivation is something like codominance ? because the two phenotypes are express?
Is this also the same as when some people have different skin colors on their body? Or is that epistasis as well?
Thanks for the great video!
What is the difference between x- inactivation and codominance?
In Co dominance the traits are equally expressed . In epistasis, between two different alleles . One masks the other
you, sir are a legend. :) thank you!
Professor,What's the meaning of "wad up" that you mentioned in the video?
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
Why splotches of orange, splotches of black? If its truly random, there would be orange, white, and black tiny spots or hairs throughout the cats body. Can you explain why orange hairs group together, and black... it seems X-inactivation happens to a group of cells at a time (of the same allele), instead of single cells at a time... Can you explain?
I think I figured it out... to answer my own question, lets say 6 cells get replicated from the zygote, 4 of those get the X chromosome where orange is active, 2 get the X chromosome where black is active. All the daughter cells of these "initial 6 cells", will inherit the same X inactivation pattern. Thus, they appear in groups in the phenotype. What I don't get is how these two steps happen, if they happen at all...
Thanks so much... :D
How do the cats reproduce when it is very rare to find a their male counterpart?
Wow 😳 thank you man
AMAZING!!!
when you look at a tortoiseshell cat, how do you know if it's X chromosome inactivation or co-dominance?
So in mammals certain cells inactivate different X chromosomes at random? It's not always the same X chromosome that's inactivated?
Thank you! now is clear....
Thanks man!
Same the video was really very useful!
Oops, yeah I meant to say males than females. But why is it more common in males then? Why are women only usually carriers since the X inactivation is random?
I love you Bozeman science
Wow it helps me a lot! Thx :)
How can the chromosome replicate if one of the x chromosomes is basicaly unable to duplicate itself
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...
thanks a lot
that was great! thanks
great!!
thank you sir
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?!?!
Harmya Alderson Your'e not necessarily a "female" in first 7-8 weeks. sex determination occurs later, so female and male designation are both given later. Before this, when they are "identical" they are neither 'female' nor 'male', instead they just contain the same primitive structures that will eventually differentiate into a female system or a male system...check out some reproductive embryology lectures for visual clarification! they depict this concept accurately!
And yes this is the same for cats too
Wrong... All embryos are female (human) the 1st 7-8 weeks. Sex determination only pop's up later for male... it's only after genes deterioration that it becomes a male!
I'm always surprised to see how people are ignorant on the subject! ... or refusing to accept reality!
awesome!
is femal sex determined by the prescence of two x chromosomes or a particular gene like SRY.