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Thalion
storyteller
Username: Thalion
Post Number: 369
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 10:12 am: |     |
This question is triggered by the White Deer thread over on AB, and Pine's reply about the migration of melanocytes during embryonal development.
I never really thought about it and took the evolution of spotted, striped and mottled animals as granted.
But why are there no striped or 'rumpwhite' humans?
I love deadlines. I like the whooshing sound they make as they pass by - Douglas Adams |
Da_bear
storyteller
Username: Da_bear
Post Number: 107
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 1:25 pm: | |
But why are there no striped or 'rumpwhite' humans?
You obviously haven't seem me in a hot tub.
Well tanned except for modesty areas.
However, do piebald blacks count? I know of several Black men who have white patches on their bodies. Some were born with it, I assume like a wine stain, and others have acquired the coloration.
da bear
If you choose not to decide, you still have made a choice. |
Miisa
storyteller
Username: Miisa
Post Number: 120
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 2:14 pm: | |
Bear, do you mean vitiligo? |
Pine
storyteller
Username: Pine
Post Number: 186
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 2:52 pm: | |
There is a genetic condition in humans called piebaldism, and it is caused by a mutation in the W (dominant white spotting) gene, the same gene whose expression is altered by the rumpwhite and patch mutations in mice. The gene encodes a transmembrane receptor (called c-kit) that is expressed by neural crest cells and is critical for their proper migration.
piebaldism in almost humanspeak
about the c-kit receptor, in sciencespeak, but has lots of links |
Thalion
storyteller
Username: Thalion
Post Number: 371
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 3:07 pm: | |
LOLOL, Bear, I bet that would be quite a sight.... 
But why aren't any of us striped? I mean, people used to paint themselves, so they would have seen stripes and dots as attractive...
I love deadlines. I like the whooshing sound they make as they pass by - Douglas Adams |
Da_bear
storyteller
Username: Da_bear
Post Number: 108
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 3:15 pm: | |
Bear, do you mean vitiligo?
I assume so, but I have never seen anyone who is non black with it. Perhaps just a local non typical distribution.
I bet that would be quite a sight
No complaints yet.
da bare
If you choose not to decide, you still have made a choice. |
Pine
storyteller
Username: Pine
Post Number: 187
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 4:02 pm: | |
Thalion, I haven't seen striped mice or dogs yet either. I wonder about inheritance of the striped phenotypes in cats (and zebras). |
Darsina
gatherer
Username: Darsina
Post Number: 146
Registered: 9-2003
| | Posted on Wednesday, October 29, 2003 - 4:23 pm: | |
quote:I assume so, but I have never seen anyone who is non black with it.
Well, I have two tiny little white spots. But since i) they are so tiny, ii) I'm white and iii) I don't tan much, you wouldn't notice them without being told where to look for them. Even if you know about them, they are hardly noticeable.
Hmm, why are humans not striped or have dots? Stripes and dots are useful for camouflage in an environment where sunlight and shadow alternate, stripes rather in grasslands and dots rather in wooded regions. Didn't our ancestors need this extra protection provided by a striped/dotted fur/skin, maybe because they knew other ways to avoid attacks by predators?
Thinking is the work of the intellect, dreaming its pleasure. - Victor Hugo |
Da_bear
storyteller
Username: Da_bear
Post Number: 109
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 7:03 pm: | |
Thalion, I haven't seen striped mice
http://www.critterconnection.cc/Animals/animals-ze bramice.htm
Perhaps these will do?
da bear
If you choose not to decide, you still have made a choice. |
Da_bear
storyteller
Username: Da_bear
Post Number: 110
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 7:16 pm: | |
Striped mouse genetics:
http://www.afrma.org/brindlemice.htm
Genetics
Brindle mice are genetically Viable Yellow (Avy). This places it in the “A” series of mouse genes. Brindle is dominant to every gene in that series except Lethal Yellow (Ay). Like Ay, Avy causes a tendency towards obesity. This can range from slight portliness in some mice, to extreme obesity in others.
I have to add a qualifier here. Though I have been told that Brindle is dominant to every gene other than Ay in the A series, at least with my mice that is not completely true. I have found that Brindle (Avy) is not fully dominant over Tan (at). Mice that are AvyAt are clearly Brindle on top, but lack any striping on their bellies. When bred to each other or to non-tan selfs, Tans and Foxes of various colors are produced. Brindles who do have striped bellies do not produce Tan/Fox youngsters.
One of the fun things about Brindle is that you can get it in a number of different colors. For those interested in breeding these colors, the genetics are fairly straight forward.
Brindle Color Description Genetic Code
Fawn/Black Orange with black stripes Avy_
Red/Chocolate Red with brown stripes Avy_bb
(combining Brindle &
chocolate)
White/Beige White with beige stripes Avy_cece
(combining Brindle
& Beige)
Silver White or pale cream with
black/dark gray stripes not sure, quite possibly
Avy_cchcch
(combining Brindle
with chinchilla)
Gold/Blue Gold with blue stripes Avy_dd
(combining brindle
with blue)
These represent the color combinations that I have tried or had pop up. There are many others that could be experimented with, and I couldn’t begin to predict the results.
English Brindle
Some confusion has arisen about the genetics and health problems of Brindle mice. Much of this is caused by the fact that there are two genetically different mice which are called “Brindle.” To the best of my knowledge, the folks in England do not have the tiger-striped color we call Brindle. Instead, they have mice that have an interesting pattern (almost like a tortoiseshell). This color is lethal when seen on male mice, and they die very shortly after birth. Examples of these mice do exist here in the United States, though not apparently on the west coast. Genetically, England’s mice are what the scientific literature refers to as Brindle. The American version, however, comes much closer to looking like the brindle seen on other species.
Breeding Brindle
Producing more Brindle mice is, fortunately, very simple. Brindle is dominant, so any time you breed a Brindle, you should get some Brindle babies in the resulting litter.
............................
I hope this is a start.
If you choose not to decide, you still have made a choice. |
Pine
storyteller
Username: Pine
Post Number: 188
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 7:50 pm: | |
Very interesting, bear! Especially since the stripes run lengthwise! I wonder how that happens. |
Da_bear
storyteller
Username: Da_bear
Post Number: 111
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 8:44 pm: | |
I was actually looking for the 13 striped chipmunk of "chip and Dale" fame.
But this was spot on.
As it lives in the grasslands, I must assume it climbs for seeds to eat, and the lengthwise stripes mimic the shadows and brown grasses.] as it clings to the upright stalks.
That's my guess.
The chipmunk is also lengthwise striped.
da bear
If you choose not to decide, you still have made a choice. |
Miisa
storyteller
Username: Miisa
Post Number: 121
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 9:22 pm: | |
Don't wild boar piglets have very similar stripes? They were the first thing I thought of when I saw the photos.
I wonder how the camouflage works for them? |
Rhi
storyteller
Username: Rhi
Post Number: 78
Registered: 5-2003
| | Posted on Wednesday, October 29, 2003 - 10:47 pm: | |
Ooh, those stripey mice are so cute. I never had a striped one, but I did have some with spots. A pure white and a silvery-brown had 6 black babies, three with tiny white spots on their heads, and one of those with a large white spot on its belly. When the silvery-brown had more babies with one of her pure black babies, there was a silvery-grey, a plain brown, and another black.
Mostly Harmless |
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