SILKIE colors and what do you get when you cross colors

[catwalk]

Quote:
I need a class. I'm not gettin' it with my own online study! I'm a nurse, you would think I could get a grip ... but, NO!

Maybe your head is too full of nursey stuff! I know that when I have a lot to know, turning the information into analagies or quick phrases works. Kinda like "listen left to be right" for intubation? (I'm an EMT)

ie - think of recessive white as paint. Each white gene is a quart of paint, but one quart isn't enough to paint your chicken. You can't just paint part of him, you need two quarts (white genes), and then he'll be white. If he only has one, he keeps it in the can to pass on to half his offspring.

 

[Sonoran Silkies]

First learn basics: definitions of dominant, incompletely dominant, recessive, allele, homozygous, heterozygous (often abbrevisted hom and het). Then start with one gene that interests you. Learn how to work a punnet square for that gene. Now go to another gene that interests you and learn about it. Keep on going.

 

[Three Cedars Silkies]

Quote:
I need a class. I'm not gettin' it with my own online study! I'm a nurse, you would think I could get a grip ... but, NO!

Maybe your head is too full of nursey stuff! I know that when I have a lot to know, turning the information into analagies or quick phrases works. Kinda like "listen left to be right" for intubation? (I'm an EMT)

ie - think of recessive white as paint. Each white gene is a quart of paint, but one quart isn't enough to paint your chicken. You can't just paint part of him, you need two quarts (white genes), and then he'll be white. If he only has one, he keeps it in the can to pass on to half his offspring.

This is good...keep going. I now have the white thing down (I'm a nurse too

)

 

[Sonoran Silkies]

I think of recessive white as an OFF switch--it turns OFF the plumage colours and patterns that are genetically present in a bird. Since you cannot see them, you cannot select for or against them, and after a few generations you have no idea what any individual bird is underneath the white.

 

[kathyinmo]

OK, these are great tips! Thanks so much! I think I was just spending too much time figuring out where the allele is, in the overall picture. I was focusing on how many and where, etc. So, now I am this far:
A gene is a piece of DNA that carries information about a specific trait.

A chromosome is a string of genes connected together (although most of the chromosome is DNA that has no known function or no genetic activity).

An allele is a gene that is a member of a set of genes that all belong to the same locus, or location, on a chromosome. These genes are often thought of as being related to each other through mutations (one allele could be a mutation of another allele) or they could be mutations of an ancestor gene.

Chickens, like people, usually have two of every chromosome. The chromosomes in a chromosome pair are not identical, since one comes from each parent. A gene is said to be dominant when only one gene (rather than two) is sufficient for the expression of that trait to which the gene corresponds. Some genes are referred to as incompletely dominant. The expression of these genes is inhibited by (usually unknown) modifying genes. When the inhibiting, modifying genes are not present, the incompletely dominant gene expresses. This interaction with modifying genes is responsible for the seemingly random nature of the expression of incompletely dominant genes.

 

[kathyinmo]

Quote:
To the OP .... I just hatched these. The parents are all penned together for the winter ... the roos are Splash, Buff, White. The hens are blue, buff, white. Here are the results. Note the 2 in there that are not silkies (they have yellow beaks and feet) ...

 

[Sonoran Silkies]

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I like to think of a chromosome as a child's shape sorter toy. Each locus corresponds to a differently shaped hole, the alleles for that hole are all the blocks that are the correct shape, but they can be any colour (indicating that they have a different affect). The gene is usually named for the affect it has on a bird. For example, the blue gene dilutes black pigment, the mahogany gene deepens the colouring of gold pigment, the extended black gene causes areas of the bird which would be gold to be black instead, etc.

Your definitions are correct except for incompletely dominant. It is an intermediate expression between the alternative alleles. Modifying genes have no particular bearing on an incompletely dominant gene any more than they do on a dominant or recessive one. If the modification is to inhibit expression, it will occur with dominant or recessive as well. The blue gene is an excellent example of an incompletely dominant gene. One copy of blue (Bl/bl+) dilutes black to blue; two copies of blue (Bl/Bl) further dilutes the plumage to splash.

To your definition of recessive, I would add that in a hen, one copy of any sex-linked gene is sufficient for the gene to express, as there can be no alternative more dominant version.

 

[L0rraine]

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So white is independent of color? So someone mentioned earlier in the thread, I think, that sometimes it does create unpredictable lighter variations (or that's how I interpreted what was said). Is there an unpredictable 'dimmer switch' action

My understanding is that black acts similarly in ducks, but that it's incompletely dominant letting some of the original color come through (but that's not what causes the partridge color right?). Does it allow for the lavender variations? OOOOhhhh my head always hurts when I try to go here.

Could you just write a book? (with a few genetic collaborators, if you like) (or maybe just a pamphlet) - I KNOW IT WOULD SELL!! and don't forget to include the bearded/non-bearded genetics as well -

Not sure what smiley is appropriate. The ones for how much your expertise is appreciated, how desperately we need this book or how funny we all are that we want to know soooooo badly.

p.s. I purchased a "Genetics for Dummies" book recently which got rave reviews on Amazon by all levels of readers, but it didn't appear that useful to the understanding of color genetics, but my husband's son (who is starting graduate study in bio-engineering) absconded with it before I got to give it much of a chance.

 

[L0rraine]

Whoops sent my reply through before I saw your last submission.

 

[Sonoran Silkies]

Quote:
It's already been done: see www.chickencolours.com (Genetics of Chicken Colours by Sigrid van Dort, David Hancox & Friends). David is blackdotte.