How do you think eye colour is decided
Is it inherited, just luck or as a result of the merle gene covering the eye? If so how can you get a solid dog with blue eyes

What is your opinion :smiley2:

Hi
I always believed that blue in the eye was an indication of the presents of too much Merle gene, I still do, yet must admit to meeting a very dark almost solid black Aussie yesterday at a trial who indead had one blue eye.
I know there was a write up regarding the Merle gene and how it affected the eye color, I will search and see if I can locate it, I seem to remember it was on Border Collies who can also produce Merle in their coat colors as well.
If anyone knows of a site on eyes give us a heads up, it would be a great addition to the forums information.
Wkelpie I would be interested in your opinion and meg&brad come on guys what do you think?.
:gleam:

Hi all,
Eye color can be caused by: inheritance or color dilution.

A dog can have blue eyes because they inherited the color.

Color can also be responsible for eye color. A dog that is lacking pigment on the head (white head), the eye color will also be without pigment. Sometimes the blue will be so pale it appears to be white.

Merle, as we all know, is responsible for blue, green, brown/blue, green/blue, brown/green eyes.

There is a rare genetically inherited disorder called Waardenburg Syndrome
http://www.drlera.com/waardenburg_syndrome.htm this same syndrome affects humans, as well as dogs.

There isn't much to be found on eye color, but here is what I have:
http://www.uwsp.edu/psych/dog/LA/DrP4.htm
http://www.uwsp.edu/psych/dog/LA/davis2.htm
http://members.optusnet.com.au/~safcav/Tra...rPerception.htm

Different color eyes are fairly rare in humans, but common in dogs such as
Dalmatians and Australian sheep dogs, and in cats and horses. The condition is
called "heterochromia" and it is usually benign, and frequently genetic in
origin.

Sometimes "heterochromia" is a result of diseases such as Horner syndrome,
Waardenburg syndrome, or piebald syndrome.

Heterochromia occurs in maybe 1 percent of the population however we need to
bear in mind to further limit this number to humans with genetic predisposition
to producing blue and green eyed offsprings. Therefore this should exclude
peoples of Asian and African origin who may not be genetically predisposed to
produce blue or green eyed offsprings.
This information was reported by StraightDope.com

Some famous people with eyes of two different colors include:
David Bowie, Christopher Walken and Kiefer Sutherland

Definition of Heterochromia
http://www.healthcentral.com/mhc/top/003319.cfm



Definition of “somatic mosaicism” by Christopher Carlson, Grad student Genetics
MadSci Network, Washington University

http://www.madsci.org/posts/archives/dec96...69191.Ge.r.html

Information regarding Horner syndrome, Waardenburg syndrome, or piebald
syndrome:

http://www.bios.niu.edu/johns/diff_eye.htm


Useful Background information about Eye color:

Definition and some information about eye colors:

http://www.straightdope.com/classics/a971205.html

How are Human Eye Colors inherited?:
http://www.athro.com/evo/gen/inherit1.html

Eye color genetics Calculator:
http://www.athro.com/evo/inherit.html

Figuring out how genes combine using the Punnett Square method:
http://www.athro.com/evo/gen/punnett.html

Working out Punnett Square Examples
http://www.athro.com/evo/gen/geframe.html

Phenotypes and Genotypes for human eye colors:
http://www.athro.com/evo/gen/geframe.html

Search Terms: Eyes of two different color

http://www.google.com/search?q=Eyes+of+two+different+color

Here is an URL to a German Shepherd that has the Waardenburg syndrome. Her name is Franka.

http://www.lewcinkaskennels.com/index1.html

Thanks Wkelpie:
Stupid question, is there a way to distinguish between an inherent factor and a genetic one as in the case of the eyes how far back must you go through the blood line before you can say with any confidence that it is either one or the other.
Second question if you are breeding black eye to black eye and a pup has a blue eye is this an indication of genetics or inherent.
I still breed Koolie's with a blue eye back to solid color Koolie's with 2 black or brown eyes even if the first Koolie has a strong color, in order to avoid problems.
Is there a DNA test which can tell if the blue eye in Koolie's is an indication of too much merle? :gleam:

Hi Wkelpie

Thanks for the info, I haven't quite checked out each link yet but it would seem that eye colour is not something you can breed for, there is a lot of luck as to which colour results.

The reason I asked the question in the first place is that some people cling to the belief that for a koolie to be "pure" it should have at least one eye blue. I have no problem with people having a preference for their dogs to have a blue eye (or 2) but to state it is a sign of purity I think would paint us into a very small corner quickly, genetically. Also in some litters you may have one or 2 pups with a blue eye but there is no way they can be purer than their litter mates who have brown eyes. (Same goes for those who state merles are pure and solids are not)

The German Shepherd your link went to was very interesting, they were obviously stunned by her arrival but historically they are a very young breed made up of several breeds of varying colours and coat patters, I am amaized that they don't have a lot more of these hiccups. Some information we were given from Germany states that the Tiger dog is an ancestor of the German Shepherd. There is some possiblity that the Tiger is also an ancestor of the Koolie, with an amaizing likeness to some of our dogs. How long before a merled shepherd arrives :o

Thanks again for your info.

:smiley2:

Tjukurpa,
No question is ever stupid. Sorry it's taken me so long to respond to this. My Koolie bitch had her pups last night ... and on until this morning. She had TEN! Whew ..... 6 boys, 4 girls ---- 3 brown[choc] merle and 7 brown [choc] and tan. I'll get them posted in the proper place, soon.

Now your questions:
Inherited may come from a line of ancestors that carry and produce the blue eye on dark colored, non-merle, non-white headed dogs.

Color inherited eye color would come from white headed dogs (lack of pigment in hair and iris -- blue is actally a lack of pigment) and merle coloration. A white headed dog with dark pigment around the eyes will sometimes have brown or dark colored eyes. One with no pigment (pink around the eyes) will usually have blue eyes (pigment varying from very pale, almost white, blue to sky blue).

Dark eye to dark eye --- both parents will have to carry the gene for blue eyes, before blue eyes can be produced. Although, something else may be at play to cause blue eyes from dark eyed parents, like Waardenburg's syndrome. I would say if the puppy is white headed with no pigment around the eyes (pink skin) and the eyes were blue, then it's more than likely color related.

Too much merle: not possible, well ... I guess you could count double merle as being "TOO" much. A dog is either merle or he isn't. M/m -- merle (merle + non-merle), m/m -- non-merle, M/M -- double merle (merle + merle). Being M/M -- double/homozygous merle would concern me and would find it interesting if a double merle had brown eyes. Anyone produce one? I've never seen one with solid brown eye's before.

I wouldn't be afraid of breeding blues to blues, but would be very hesitant in breeding merle to merle (especially the ones with a lot of white). Piebald to piebald, I wouldn't do either, in this breed (Jack Russell's I would, but not Koolies, BC's or Corgi's).

Okay, must get outside --- will talk to you guys later ---

I mean blue eyes to blue eyes or any combination of blue/brown eyed dogs.

Thanks for the clear up Wkelpie, I think I still go all fuzzy in the head when you talk of genetics, and thanks for the clearification on blue to blue mating being eyes, that one threw me.
I can't wait to see your babies, make sure mum and dad get in the shot :throb: