Between your visuals and the way you simplify your teachings, it makes it very simple and easy to understand concepts that I was previously struggling to understand, Thank you.
I legit made a RUclips account so i could comment on this. Im watching this video for my Biology 115 exam. You are saving my grade and I thank you very much!!!! Sooooooo helpful
I just love these videos u make!!! Everything makes sense. It shows the reasons behind what cells do and why they do it. This has being so helpful in my courses! Thank you so much!
Thank you for taking something as complex as epigenetics and making it easy to digest, especially for those who do not have a strong grasp on biology or physiology...my undergrad psych students thank you as well :)
I'm not in a class or anything. I'm just trying to learn more about Epigenetics because I think it's a fascinating subject. Your video is very helpful and easy to follow. Thanks.
I am so glad I found you! The way you describe each lesson is so easily understood. I wish you were my teacher instead of the condescending one I have now.
I love these videos! I'd like to clarify that at the end when he was talking about how if someone's parents have diabetes they are more likely to pass it on to their child, he is referring to Type 2 Diabetes. People who become overweight and developed Type 2 Diabetes change their epigenetics, while in Type 1 Diabetes there is nothing you can do to prevent it or induce it.
Hi Paul, I can't thank you enough for the brilliant content you put up here for free. I'm a Genetics major and every time I face a problem I know I can rely on you and Shomu's Biology for explanations. I was pretty stressed out looking through my lecture notes, and this really helped clear things up. Thank you, and much love from Malaysia
Ok, so the answer to my question boils down to "it's an area of current research". that's both slightly frustrating and exciting. Thanks for the paper. I'll read that as soon as possible and see whether it's on my level and answers some of my questions. Epigenetics is such an interesting topic.
How do cells make sure that only the right bits are switched on or off? - in both systems. Also, how do you inherit such switches from your parents? Last time I heard this, you could have a transfer of some such traits by your mother easily but father-side epigenetic traits don't transfer. Is this incorrect?
Cells know where they are in the embryo because of protein gradients. The fertilized egg has proteins that are highest in concentration at one end of the cell and lowest at the other end. When the cell divides, one of the daughters will have less of the protein (the one from the end of the egg at the low concentration side of the gradient) and the other will have more of the protein. These proteins are usually transcription factors, that will turn on new gradients.
That's really really helpful for me. The concept of epigenetics was very confusing for me before. Now you make it super clear. Thannnnks very very much!
There's one thing I am confused about. So if the histones are wrapped around our genes, and say you become a smoker (but no one in your family tree extending hundreds of years smoked) and the chemical tag is added to the histones to make that gene become 'expressed', does that mean that the 'smoker gene' is predetermined? In other words, will I have a 'smoking gene' by default that is turned off, but will only be turned on if I smoke?
I didn't get how can you pass epigenetic modification you chromosome to kids. Especially on the context of diabetes. Shouldn't spermato and oogenesis be separated from all the epigenetic modifications?
I don't think we've got enough data to answer those question yet. "Molecular Signals of Epigenetic States" is a good paper on this. If a mark is there, we know how it is maintained. How it's established is less known. Double stranded RNA (often from repetitive sequences that fold back on themselves) directs proteins to silence sequences complimentary to the dsRNA by marking histones and methylating the DNA. Proteins or RNA inherited in the cytoplasm can also direct the initial silencing.
methylation can activate and also deactivate genes depending on place of methylation and degree of methylation. H3 K4 methylation is activation mark . H3 K9 is deactivation mark of genes.
Hey Mr Anderson, Thanks a Lot for the Awesome videos... very simple and precise.. The videos are nicely illustrated and clear.. Great work..!!!! Time saving and easy to understand.. Keep up the good work..!!!! :)
I got a graduate certificate in clinical pathology and am now working on an MS in pharmacogenomics and I swear this guy should walk up for my diploma with me, because when I don't understand something I start here.
I see. So basically, the chance is slimmer but it's there. I really hope to hear more about Epigenetics on a level that can be taken by non-experts. - All I found on it were either fairly basic explanations around the level of this video or super technical papers way beyond my scope.
In epigenetics, Ipso Facto, you are more related to your grandparents than your parents. This is because while your grandparents carry an "on" gene (let's say), it will be turned "off" in the next generation, then back "on" when you are born. That's why if you want to know more about yourself, ask your grandparents what kind of lives they lived when they were younger.
What about histone methylation? How does that affect DNA packaging and why does it sometimes lead to repressed transcription and sometimes to activated transcription?
Thank you soooo much for all the video you posted. You have helped me and my classmates in ways you may not understand. Please continue to post these video....Can you do one on inheritance patterns,the Molecule of Heredity and the Gene Expression and Regulation?
The histones are removed and replaced by protamines in sperm development, so it's unlikely modified histones would be inherited from the father. Genome-wide DNA demethylation occurs twice in early development so it would seem inheritance of these states isn't possible. However, some marks clearly survive demethylation and histone replacement; imprinted genes are expressed differently depending on weather they were inherited from mum or dad and such marks can be inherited from the father.
I'd tend to agree with you. If environment influences how genes are expressed, it's only because the genome encodes the proteins and DNA elements that mediate epigenetics. It's worth treating seperate until more is known about how it works and it can be more incorporated with genetics, we must be careful not to make it sound like woo. A lot of this is due to the history - a lot of the guys who first pushed epigenetics seem to have been opposed to 'the central dogma.'
Can someone explain further how epigenetics are inherited? There seems to be no histone acetylation or methylation of the first cells of an embryo because they have no expression of any particular genes yet. How is something like diabetes passed on if gametes, sex cells, and stem cells are undifferentiated and basically a blank slate?
Research has shown that sometimes epigenomes are imprinted within the gametes, yes it is often for the epigenomes to be erased while the gamete is created, but there are some imprints that get passed on. Go search Ted ed
Hi Mr. Anderson, Thank you so much for making these videos! They are very helpful. One question here: the addition of a methyl group to cytosine causes the DNA to lose its affinity to its DNA binding proteins such as transcription factors at that site. Since transcription initiation requires two types of transcription factors (one bind to the TATA box and the other bind to the various regulatory sites of particular genes) to bind to a gene, the transcription factors can no longer bind to the methylated region, which means no mRNA can be formed, hence no polypeptides will be translated? Thank you in advance!
It's hard to simplify this issue the way you do to something as understandable as this video. The heritability (through meiosis) of epigenetic marks isn't well established. New methods will give us a lot more info on epigenetics soon enough. I like how so many disparate mechanisms work together to regulate so many different processes. Differences in epigenetics between species make it hard to teach. Maybe some general principles (like a histone code) will come out of further research?
These proteins don't last long though so the positional info they give is temporary. The proteins direct epigenetic mechanisms to turn genes off in a more permanent way. The proteins from the gradient bind specific DNA sequences (found in the promoters of genes that need to be turned off in that cell type) and also bind enzymes that methylate DNA or modify histones. (I think that's what the "zone of polaring activity" comment was getting at)
I know too little about this for that comment to be helpful but thanks. (I have no idea what the zone of polarizing activity is in this context.) If you have time, I'd love to hear a more detailed explanation.
i realize epigenetics deals mostly with proteins and RNAs, but i always thought it should be portrayed as more of an extension of genetics it just seems to be talked about as this separate thing from the genome, rather than just how the environment (and ultimately DNA based regulation) influence the genome
I thought Dna Methylation would lead to increased transcription as it forms areas of " Z DNA". With Z-DNA being more loosely packed wouldn't transcription increase i.e.: euchromatinized genes? any explanation would be helpful
Great video ... now here's a man who understands epi enough to explain the genetics ... any "gut" thoughts on how to reverse epigenetic damage? Are there any suspected or known mediators? Thanks for the intelligence.
Very good quick video, thank you! Just one queston, can anyone please explain the mechanism by which certain cells determine which portions of the DNA to methylate and which lysine amino acids are acetylated. I find it very interesting how different cell type can identify which portion of the DNA gets unreadable. For example, in a heart cell, how is it determined which portion of the DNA gets methylated and which portion of the histones get acetylated so that only heart cell DNA is expresed? Thank you!!!
Methyl groups are hydrophobic, so don't interact very well with water. As the environment of a cell is very aqueous (watery), addition of methyl groups to the DNA induces tighter wrapping of the DNA around the histone proteins. If you like, the methyl groups on the DNA "hide" from the external environment. tighter packaging of the DNA thus decreases the chances of successful transcription... :)
Thank you! Great help to explain it to others. My MS kicks in when I eat gluten etc. I need no gluten/dairy/soy/sugar/GMO/food with a label/heated oils...take vitamins/good oils/minerals..probiotic...LDN..detoxing to be alright.
It all made sense at about 8:30 for me. I got here by way of a study that showed that induced behavioural traits in mice can be passed on to next generation mice - even when artificial insemination is used along with strict isolational environmental controls - a bit like Pavlov's dogs having puppies which salivate when they hear a bell - despite the puppies having been produced by artificial insemination in a different country. Nearly as weird as cannibal worms who inherit memory from worms they have eaten. I only found out about epigenetics today. Weird Science!
I never understood this: If you block a gene from being expressed, what gene is expressed in it's place? Wouldn't it be a wrong one, for example heart cell instead of skin cell? Is there an alternative healthier gene? It can't be nothing. If i have, let's say, a mutated finger and i block that gene off, what would be in it's place? I think is absurd that there would be no finger.
oh goodness i hope someone replies before my test, but is methylation reversible or is it only irreversible? there's been videos about demethylation but none with a super clear explanation that i've understood. and i understand that methylation is what keeps one of the two x chromosomes silent in females and becoming fatal, so that makes me wonder if demthylation can ever occur to make that other x chromosome appear once again??
Between your visuals and the way you simplify your teachings, it makes it very simple and easy to understand concepts that I was previously struggling to understand, Thank you.
you successfully explained this topic in under 10 minutes while my lecture couldn't do it in an hour! ... love your videos thank you!
Mr. Andersen, you are a wonderful teacher!
I legit made a RUclips account so i could comment on this. Im watching this video for my Biology 115 exam. You are saving my grade and I thank you very much!!!! Sooooooo helpful
You're fantastic at teaching. I'm studying for the MCAT-this was very helpful!
What did you get?
I just love these videos u make!!! Everything makes sense. It shows the reasons behind what cells do and why they do it. This has being so helpful in my courses! Thank you so much!
you're like my favourite lecturer ever!
Thank you for taking something as complex as epigenetics and making it easy to digest, especially for those who do not have a strong grasp on biology or physiology...my undergrad psych students thank you as well :)
Best of all other videos. The host is super clear ! Thank you
This man is excellent at explaining relatively complicated topic.brilliant stuff
I'm not in a class or anything. I'm just trying to learn more about Epigenetics because I think it's a fascinating subject. Your video is very helpful and easy to follow. Thanks.
I am so glad I found you! The way you describe each lesson is so easily understood. I wish you were my teacher instead of the condescending one I have now.
Waw, what an explanation, what a presentation! Astonishing!
In med school right now, rewatching some of these vids for my biochem exam :D
you provided the basic informtation in a simple way, that was very helpful. Thanks,
I love these videos! I'd like to clarify that at the end when he was talking about how if someone's parents have diabetes they are more likely to pass it on to their child, he is referring to Type 2 Diabetes.
People who become overweight and developed Type 2 Diabetes change their epigenetics, while in Type 1 Diabetes there is nothing you can do to prevent it or induce it.
How is lifestyle affecting which genes are expressed? Can u elaborate a bit wrt diabetes?
I gotta say, this video is awesome. I have final exam tomorrow, and this is super, duper helpful!
I am hoping to get a 5 on my AP Bio test and trying to cover every lurking detail and gain conceptual understanding; your videos do the job!
Hi Paul, I can't thank you enough for the brilliant content you put up here for free. I'm a Genetics major and every time I face a problem I know I can rely on you and Shomu's Biology for explanations. I was pretty stressed out looking through my lecture notes, and this really helped clear things up. Thank you, and much love from Malaysia
The fact that these are still helpful 7 years 😂🤯👌
Awesome, thank you. I'm studying for exams and our teachers have to make this stuff impossible. This really helps a lot
Ok, so the answer to my question boils down to "it's an area of current research". that's both slightly frustrating and exciting.
Thanks for the paper. I'll read that as soon as possible and see whether it's on my level and answers some of my questions. Epigenetics is such an interesting topic.
you are making my life so much easier
I hope you were the teacher of the year in Montana! Awesome presentation of material. Thanks for your efforts.
Thanks for the clear and simplified explanation of a complex process.
You are an AMAZING present!!!!! LOVE all of your analogies!
How do cells make sure that only the right bits are switched on or off? - in both systems.
Also, how do you inherit such switches from your parents? Last time I heard this, you could have a transfer of some such traits by your mother easily but father-side epigenetic traits don't transfer. Is this incorrect?
Cells know where they are in the embryo because of protein gradients. The fertilized egg has proteins that are highest in concentration at one end of the cell and lowest at the other end. When the cell divides, one of the daughters will have less of the protein (the one from the end of the egg at the low concentration side of the gradient) and the other will have more of the protein. These proteins are usually transcription factors, that will turn on new gradients.
thanksss please will continue to increase! Biological explanations for things even more complicated
my favourite biology lessons are urs..thank you so much
So.... lamark was right but he just got it wrong ? :P
That's really really helpful for me. The concept of epigenetics was very confusing for me before. Now you make it super clear. Thannnnks very very much!
Hope it's helpful.It is so helpful that i can't even describe it.Thank you so much for all of your videos.
There's one thing I am confused about. So if the histones are wrapped around our genes, and say you become a smoker (but no one in your family tree extending hundreds of years smoked) and the chemical tag is added to the histones to make that gene become 'expressed', does that mean that the 'smoker gene' is predetermined? In other words, will I have a 'smoking gene' by default that is turned off, but will only be turned on if I smoke?
I have a test in eight hours and this was incredibly helpful. Thanks!
I didn't get how can you pass epigenetic modification you chromosome to kids. Especially on the context of diabetes. Shouldn't spermato and oogenesis be separated from all the epigenetic modifications?
Love your videos, I just have a question: How is the epigenome inherited if all the acetyl groups are removed from the gamete DNA?
This was AWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWsome. Nice refresher. Now I can check out Dr. Lipton's video on Epigenetics. Thanks Bozeman!!!
What's the difference between gene regulation (enhancers, promotor region, etc) and epigenetics (methylation, aceytalation, microRNA)?
Sweet. I've been waiting for this video to come out since last year's AP exam.
September 20,2022! Thanks so much.
I don't think we've got enough data to answer those question yet. "Molecular Signals of Epigenetic States" is a good paper on this. If a mark is there, we know how it is maintained. How it's established is less known. Double stranded RNA (often from repetitive sequences that fold back on themselves) directs proteins to silence sequences complimentary to the dsRNA by marking histones and methylating the DNA. Proteins or RNA inherited in the cytoplasm can also direct the initial silencing.
OMG you are the best. You make everything sound so easy.
methylation can activate and also deactivate genes depending on place of methylation and degree of methylation. H3 K4 methylation is activation mark . H3 K9 is deactivation mark of genes.
Hey Mr Anderson, Thanks a Lot for the Awesome videos... very simple and precise.. The videos are nicely illustrated and clear.. Great work..!!!! Time saving and easy to understand.. Keep up the good work..!!!! :)
Great vídeo! How a dominant allele is selected (ignoring the recesive)? Si it an epigenetic process? Muchas gracias!
You are awesome. Your lecture videos has been very helpful
I got a graduate certificate in clinical pathology and am now working on an MS in pharmacogenomics and I swear this guy should walk up for my diploma with me, because when I don't understand something I start here.
I see. So basically, the chance is slimmer but it's there.
I really hope to hear more about Epigenetics on a level that can be taken by non-experts. - All I found on it were either fairly basic explanations around the level of this video or super technical papers way beyond my scope.
In epigenetics, Ipso Facto, you are more related to your grandparents than your parents. This is because while your grandparents carry an "on" gene (let's say), it will be turned "off" in the next generation, then back "on" when you are born. That's why if you want to know more about yourself, ask your grandparents what kind of lives they lived when they were younger.
Can you please do a podcast on plasmid mapping and protein synthesis? I'm struggling with those in AP bio and your podcasts always help me a lot!
Love this dude. Helped me in school now helps with curiosity. I am a college dropout
If I'm not mistaken, methylation doesn't exclusively deactivate/turn off gene expression. It can also, although far less common, activate/turn it on.
I have a bio midterm tomorrow, and epigenetics is on it... So THANKS :D I am glad you posted this video!
remember ur comment from 8 years ago?
Awesome video, uploaded just as i needed it
Hocam iyi ki var olmuşsunuz
What about histone methylation? How does that affect DNA packaging and why does it sometimes lead to repressed transcription and sometimes to activated transcription?
Thank you soooo much for all the video you posted. You have helped me and my classmates in ways you may not understand. Please continue to post these video....Can you do one on inheritance patterns,the Molecule of Heredity and the Gene Expression and Regulation?
remember ur comment from 8 years ago?
The histones are removed and replaced by protamines in sperm development, so it's unlikely modified histones would be inherited from the father. Genome-wide DNA demethylation occurs twice in early development so it would seem inheritance of these states isn't possible.
However, some marks clearly survive demethylation and histone replacement; imprinted genes are expressed differently depending on weather they were inherited from mum or dad and such marks can be inherited from the father.
I'd tend to agree with you. If environment influences how genes are expressed, it's only because the genome encodes the proteins and DNA elements that mediate epigenetics.
It's worth treating seperate until more is known about how it works and it can be more incorporated with genetics, we must be careful not to make it sound like woo. A lot of this is due to the history - a lot of the guys who first pushed epigenetics seem to have been opposed to 'the central dogma.'
thanks a lot, it's very well explained in a very simple way
Can someone explain further how epigenetics are inherited? There seems to be no histone acetylation or methylation of the first cells of an embryo because they have no expression of any particular genes yet. How is something like diabetes passed on if gametes, sex cells, and stem cells are undifferentiated and basically a blank slate?
Research has shown that sometimes epigenomes are imprinted within the gametes, yes it is often for the epigenomes to be erased while the gamete is created, but there are some imprints that get passed on. Go search Ted ed
3 seconds in ya might as well hit the like button cause this dude ALWAYS does an amazing job
remember ur comment from 8 years ago?
Hi Mr. Anderson,
Thank you so much for making these videos! They are very helpful. One question here: the addition of a methyl group to cytosine causes the DNA to lose its affinity to its DNA binding proteins such as transcription factors at that site. Since transcription initiation requires two types of transcription factors (one bind to the TATA box and the other bind to the various regulatory sites of particular genes) to bind to a gene, the transcription factors can no longer bind to the methylated region, which means no mRNA can be formed, hence no polypeptides will be translated? Thank you in advance!
It's hard to simplify this issue the way you do to something as understandable as this video. The heritability (through meiosis) of epigenetic marks isn't well established.
New methods will give us a lot more info on epigenetics soon enough. I like how so many disparate mechanisms work together to regulate so many different processes. Differences in epigenetics between species make it hard to teach. Maybe some general principles (like a histone code) will come out of further research?
thank you so much this was very helpful in piecing together what my teacher says in class!!!!
OH Thanks so much! Yes! So helpful. You just made this super clear!
This is a very informative lesson. Thanks a lot.
These proteins don't last long though so the positional info they give is temporary. The proteins direct epigenetic mechanisms to turn genes off in a more permanent way. The proteins from the gradient bind specific DNA sequences (found in the promoters of genes that need to be turned off in that cell type) and also bind enzymes that methylate DNA or modify histones.
(I think that's what the "zone of polaring activity" comment was getting at)
It has to do with where the cells are positioned during development. A good example of this is the zone of polarizing activity.
I know too little about this for that comment to be helpful but thanks. (I have no idea what the zone of polarizing activity is in this context.)
If you have time, I'd love to hear a more detailed explanation.
i realize epigenetics deals mostly with proteins and RNAs, but i always thought it should be portrayed as more of an extension of genetics
it just seems to be talked about as this separate thing from the genome, rather than just how the environment (and ultimately DNA based regulation) influence the genome
Thank you. Clear and helpful !
clear & very simple ,,, thanks very much (Y) :D
Excellent video! Thanks
I thought Dna Methylation would lead to increased transcription as it forms areas of " Z DNA". With Z-DNA being more loosely packed wouldn't transcription increase i.e.: euchromatinized genes? any explanation would be helpful
Great video ... now here's a man who understands epi enough to explain the genetics ... any "gut" thoughts on how to reverse epigenetic damage? Are there any suspected or known mediators? Thanks for the intelligence.
excellent explanation, but did he mean by miRNA the noncoding Xist and Tsix, hope anyone replies.
Great explanation
Amazing videos... I always learn so much! Thank you,Mr. Anderson.
I just wanna know what is the name of software that you made this vedio， thanks！
This is Very very helpful. Thank you so much!
Yeah, he really did a great explanation. Thanks a lot, I'll look into that. :)
Cool stuff brother, I explain things very well. I get it better now
this was such a good explanation
Omg there are no words...just thank u thank u thank u!!!
Very good quick video, thank you! Just one queston, can anyone please explain the mechanism by which certain cells determine which portions of the DNA to methylate and which lysine amino acids are acetylated. I find it very interesting how different cell type can identify which portion of the DNA gets unreadable. For example, in a heart cell, how is it determined which portion of the DNA gets methylated and which portion of the histones get acetylated so that only heart cell DNA is expresed? Thank you!!!
U r so good at explaining.
Thank you. Very good explanation!
Very well explained. Thanks so much!
SOOOO awesome!!! LOVE this one!
Methyl groups are hydrophobic, so don't interact very well with water. As the environment of a cell is very aqueous (watery), addition of methyl groups to the DNA induces tighter wrapping of the DNA around the histone proteins. If you like, the methyl groups on the DNA "hide" from the external environment. tighter packaging of the DNA thus decreases the chances of successful transcription... :)
Facts Mr Anderson 💯
Very interesting and informative. 🌞
this is really cool and made clear. thanks for the explanation!
Thank you! Great help to explain it to others. My MS kicks in when I eat gluten etc. I need no gluten/dairy/soy/sugar/GMO/food with a label/heated oils...take vitamins/good oils/minerals..probiotic...LDN..detoxing to be alright.
I need more! Great video
It all made sense at about 8:30 for me. I got here by way of a study that showed that induced behavioural traits in mice can be passed on to next generation mice - even when artificial insemination is used along with strict isolational environmental controls - a bit like Pavlov's dogs having puppies which salivate when they hear a bell - despite the puppies having been produced by artificial insemination in a different country. Nearly as weird as cannibal worms who inherit memory from worms they have eaten. I only found out about epigenetics today. Weird Science!
I never understood this: If you block a gene from being expressed, what gene is expressed in it's place? Wouldn't it be a wrong one, for example heart cell instead of skin cell? Is there an alternative healthier gene? It can't be nothing. If i have, let's say, a mutated finger and i block that gene off, what would be in it's place? I think is absurd that there would be no finger.
oh goodness i hope someone replies before my test, but is methylation reversible or is it only irreversible? there's been videos about demethylation but none with a super clear explanation that i've understood. and i understand that methylation is what keeps one of the two x chromosomes silent in females and becoming fatal, so that makes me wonder if demthylation can ever occur to make that other x chromosome appear once again??