Chimerism and mixed hair color/texture

[shannonsun]

Hello, LHC! I was reading about calico cats the other day and ended up on a wikipedia page about chimerism. Apparently some calico and tortoiseshell cats get their coloration in the following strange and cool way: two kitten eggs are fertilized, and each embryo has a different color pattern, but before they can develop very far, one embryo absorbs the other. When the resulting kitten grows, it shows a mottled pattern of two different colors! Instant tortoiseshell pattern!

I continued to read on the wiki page (http://en.wikipedia.org/wiki/Chimera_(genetics)#Tetragametic_chimerism) that this kind of genetic phenomenon is speculated to be extremely common in humans. Some of us might really have two sets of DNA.

I know that on my head I have super fine hairs as well as super coarse hairs. I have a patch of fine white-blonde hair in the back of my head growing from a 1.5" round patch of darker skin. Now I wonder if these difference are evidence of my long-absorbed twin!!! :bigeyes:

Anyone else have experience with strangely different hairtypes on their head?

[Nae]

Oh my. Somehow this sort of speculation seems both morbid and fascinating at the same time. I haven't really noticed anything odd but now I will be wondering if I am a twin absorber too!! ACK!

[spidermom]

I have all textures and colors of hair, although the light colors/fine to medium textures dominate. There is no history of twins in my family, so I doubt chimerism.

[shannonsun]

I have all textures and colors of hair, although the light colors/fine to medium textures dominate. There is no history of twins in my family, so I doubt chimerism.

Have you always had as many textures/colors as you do now, spidermom? Or has it changed over time? I know my blonde patch was jet black when I was born, but gradually changed during my childhood.

[Anje]

Hello, LHC! I was reading about calico cats the other day and ended up on a wikipedia page about chimerism. Apparently some calico and tortoiseshell cats get their coloration in the following strange and cool way: two kitten eggs are fertilized, and each embryo has a different color pattern, but before they can develop very far, one embryo absorbs the other. When the resulting kitten grows, it shows a mottled pattern of two different colors! Instant tortoiseshell pattern!

I continued to read on the wiki page (http://en.wikipedia.org/wiki/Chimera_%28genetics%29#Tetragametic_chimerism) that this kind of genetic phenomenon is speculated to be extremely common in humans. Some of us might really have two sets of DNA.

I know that on my head I have super fine hairs as well as super coarse hairs. I have a patch of fine white-blonde hair in the back of my head growing from a 1.5" round patch of darker skin. Now I wonder if these difference are evidence of my long-absorbed twin!!! :bigeyes:

Anyone else have experience with strangely different hairtypes on their head?
Interesting.... With most cats, though, it's the fact that one X-chromosome is inactivated, which happens in mammalian females. Which choromosome is active, in the cat's case, determines the coloring of that section of kitty.

That's also why the vast majority of calicos and tortiseshells are female. The only time you get males with that color pattern is when they're Kleinfelter's kitties (are XXY instead of XY).

[teal]

Chimerism is fascinating, isn't it? I've read through the wiki article on it before.

I think I first heard of it when a woman went in for genetic testing for her child and the child wasn't found to be related to her because her ovaries were from one set of DNA and whatever they used for testing (cheek swab?) was another set. I think I might be bungling that story. Off to see if I can find the article.

Edit: Here (http://www.katewerk.com/chimera.html).

[owlathena]

Woah! Thats so interesting! I have a friend with two different colored eyes, I wonder if that could be the same thing?

[embee]

How interesting! Thanks for the link, I sure enjoyed reading that. :)

Miss Minnie the calico cat may be a chimera? oooooh!

[Yozhik]

I had a professor with different colored eyes, which seems to be a tip off, according to that interesting article, that she might be a chimera! How cool. :)

[MandyBeth]

Chimerism isn't THAT common. If a human is, you'll see the Blashchko's lines under UV light.

[Panth]

Yes, chimerism is very interesting. However, I think you've mis-read a bit:


this kind of genetic phenomenon is speculated to be extremely common in humans.

It actually says "This has occurred in humans, and at one time was thought to be extremely rare, though more recent evidence suggests that it is not as rare as previously believed."

So, it's not extremely rare in humans. However, it is very rare. It certainly is not "extremely common". Just as well otherwise genetics in general would be one heck of a lot more difficult.

[Anje]

Chimerism isn't THAT common. If a human is, you'll see the Blashchko's lines under UV light.
Interesting phenomenon. MandyBeth, do you know what causes those lines? Clearly not everyone who has chimerism is going to have one cell line that glows and one that doesn't, so I'm guessing it's something about the interaction between the two genotypes?

[Othala]

My husband has different coloured eyes, one green/brown and one blue/green. His eyebrows are blond, his head hair is reddish-brown and his beard is black. I'm not sure if this is chimerism. Nobody else in his family has such characteristics so it is definitely a peculiar phenomena whatever it is termed.

[Orangerthanred]

I have a few hair types on my head. Some hairs are kind of fine, others are really coarse, but most of them are in between. I also have a patch of sandy blonde hair at the back of my head, in the under layer.

[slz]

I wonder if somatic mutation wouldn't be more common than chimerism ? (a mutation that occurs in a random cell after fecondation which means only part of your body will be concerned - can lead to patches of different colour, for instance, black patches in yellow labradors or golden retrievers)

[sheepofshalott]

Two different colored eyes is probably just Heterochromia like in cats and dogs. Pretty common as far as these sorts of things go.

I've seen photos in medical books of a chimera with a checkerboard pattern of dark and light skin on their abdomen. Pretty fascinating stuff. Very rare, though.

[ttverdy]

Neat! I have a very defined spot on the bottom back of my head where straight, fine, and light strawberry blonde hairs grow. They're literally a fine 1a in texture, and completely different color. I'll see if I can get a pic of it!

Here it is! It doesn't show the color difference well (dang cell phone pics) but this is my normal hair (curly) and a piece of the weird hair (straight) in after air-drying without manipulation. I've had this streak as long as I can remember.

http://i1108.photobucket.com/albums/h404/ttverdy/chimera.jpg

[Mairéad]

I am a strawberry blonde with light eyebrows and random dark hairs throughout them. I lighten those hairs. :o

I also have patches of wavy hair throughout what is normally pretty straight hair, but I always thought that was a common phenomenon.

I have a twin sister but I know that my mother reabsorbed what would have been a triplet.

[Alex Lou]

I'm seconding that fact that calico cats are not chimeras. They are cats with one X chromosome that gives an orange color and another X chromosome that gives another color. The orange once causes it though.

I was actually under the impression that chimerism is fairly uncommon in humans and that when it does manifest it is unlikely to be apparent in the skin. Meaning, the entirety of the skin will have one set of genetics, while you may be able to find different genetics in a different organ system. So, having "calico" chimera hair should be very uncommon. I have many different textures and colors in my hair and I would be very surprised if I were a chimera. That kind of variation is just normal.

[julierockhead]

This thread is just so geeky and exciting!:crush:

[Mesmerise]

Chimerism is interesting. I remember an episode of CSI where the murderer was a chimera... they did a saliva sample and he only came out as a relative of the murderer because the DNA was different from his sperm or whatever.

I suppose it could theoretically cause different sorts of hair, but wouldn't be the most common cause of odd hair. I have odd hair too that's quite curly underneath and fairly straight on top... but since joining LHC I've realised that hair like mine isn't THAT weird cause many others here have odd hair too!

[slz]

..........................

[wooliswonderful]

I always thought it was really cool that Colleen Moore had one blue eye and one brown eye. I adored visiting her Fairy Castle (http://www.msichicago.org/whats-here/exhibits/fairycastle/) when I was little and pretending it was mine. :)

[WinterButterfly]

Chimerism is interesting. But I do think having a little bit of unusual hair mixed in with your normal type happens to a lot of people. I have fine and very straight hair, except for a small percentage (maybe 1%) that is coarse and wavy. It is so out of place because my hair won't hold a wave or a curl. It only suceeds in giving me some weird frizz.

[seaj]

Those wiry hairs that most people have are nothing out of the norm. Don't people have up to 100,000 hairs on their head? I'm sure that plenty of follicles get damaged over the years, causing them to produce hairs with irregular coarse texture. I seem to have most of mine on the top of my head, though I'm not sure if it's because the rest are concealed underneath, or maybe that area gets damage to the follicles from the sun.

I actually thought about bringing chimeras up haha, especially after reading the thread for people with 2 hair types and after reading this in the wiki page a while ago.

"Most chimerae will go through life without realizing they are chimeras. The difference in phenotypes may be subtle (e.g., having a hitchhiker's thumb and a straight thumb, eyes of slightly different colors, differential hair growth on opposite sides of the body, etc.) or completely undetectable."

There is no history of twins in my family, but I sometimes think that I could possibly be a chimera. My right hand side of my body is actually hairier than the left side. It's not that prominent, but what really set me off was when I noticed I had a patch of hair on the top of foot, and no corresponding patch on my left foot. Further observation revealed that my knuckles, forearms, and shins all have more hair on the right side of my body. I haven't noticed anything drastic going on with scalp hairs though.

I have read that the nails on your dominant hand grow faster, so maybe it's just related to me being right handed?

I do recall this one pale blonde kid in middle school who had two distinct patches of really red hair. One of friends also use to let me braid her hair in high school. She had 1a hair, and a palm sized patch of wavy hair just like Galadriel's on the back center of her head. I wonder if they are chimeras.

[Altocumulus]

Interesting! I have textures ranging from 3a to 1c, and colors from light blonde to dark brown. They thought my mother was having twins when she was pregnant with me, but I turned out to be a singleton. Could I be a chimera? Maybe I'm just weird... :P

[embee]

Did someone already mention this?

http://www.foxnews.com/scitech/2011/09/30/house-cat-with-2-faces-lives-12-years-sets-record/

I see the article calls it a "Janus Cat" but it sounds sorta chimera-like to me.

I don't think I quite understand the difference between Chimera and Siamese Twins.... except that one is more separated than the other.

[shannonsun]

It actually says "This has occurred in humans, and at one time was thought to be extremely rare, though more recent evidence suggests that it is not as rare as previously believed."

So, it's not extremely rare in humans. However, it is very rare. It certainly is not "extremely common". Just as well otherwise genetics in general would be one heck of a lot more difficult.

I stand corrected! It's a pretty compelling idea from a creative standpoint though. Chimeras everywhere! There has to be a scifi crime thriller involving chimeras somwhere... :D




Here it is! It doesn't show the color difference well (dang cell phone pics) but this is my normal hair (curly) and a piece of the weird hair (straight) in after air-drying without manipulation. I've had this streak as long as I can remember.


That's amazing! I wonder what causes it!!

[cmg]

That's also why the vast majority of calicos and tortiseshells are female. The only time you get males with that color pattern is when they're Kleinfelter's kitties (are XXY instead of XY).
*Besserwissermodus on*
Calicos and tortiseshell cats are not chimeras, they are mosaic. Chimeras are different. In mosaics, the genetically different cell types all arise from a single zygote, whereas chimeras originate from more than one zygote.
*Besserwissermodus off*

Being odd-eyed is not a sign of chimerism. Oddly enough, the odd eyed people often occur in families with frequent twin births. All combinations are normally not possible though, like for example dark brown in combination with bright blue.

[Alex Lou]

Did someone already mention this?

http://www.foxnews.com/scitech/2011/09/30/house-cat-with-2-faces-lives-12-years-sets-record/Whoa! Thanks for sharing. Looks like some kind of old god!

[Katze]

I think what is more common is the incredible mixture of DNA we all have. My mom has scandinavian ancestry and fine, ii-to-thin, mostly straight, light brown hair. My dad has southern German ancestry and M-to-coarse, wiry to kinky, wavy hair. My sister has 1b straight fine thick hair, my brother (when he had hair) was a mix of M and fine, and very wavy, and I have a striking mix of fine hairs on the crown and kinky, wurly, almost 3-type hairs at my nape. Makes it very hard to take care of my hair and get enough moisture on the coarser bits!

We are all at least this much of a mix if not more...in my family and generation we have four different eye colors, my brother has very dark skin, medium ash brown hair, and black eyes but a red beard, and he started life blond, my sister also has black eyes and was born with black hair while I was bald, then blonde, and have 'hazel' eyes...genetics is really complicated on its own! Perhaps some people do have chimerism, but I doubt (in my case anyway) it has anything to do with my hair type!

[cmg]

Hmm. I have always put down my damaged "outer" hair to damage from climate, straightening, dyeing etc. (and genetics), but perhaps it has a different quality on the crown? I havent thought about this. Perhaps I should rethink my strategies. :eyebrows: