Lavender Vs. Chocolate Genetics

[Heather08]

Quote:
I dont understand these graphs, is this like a punnet square? I jsut cant make out how this works..

You can't get around the punnett square in genetics...

The "-" represents the w chromosome (the "Y" of birds if you like).
It has no chocolate gene or wildtype chocolate gene. So what is on the other chromosome (Z or the X of birds) will always show.

Also the animals with the "-" are the females.
In the lavender punnett square sexchromosome/gender is not a factor. The outcome represents both genders.

OK im starting to get it....2 more cups of coffee..its starting to click... thank you.

In chickens the W = male and Z =female ? the - = female and + = male? Just trying to peel that away first in my head... see if I have that clear.

 

[Sonoran Silkies]

In the bird world, males are ZZ and females are ZW. Z is a longer chromosome than W, so males have two copies of some genes that females have only one copy of. These genes are sex-linked.

The genotype of a choc male is choc/choc
The genotype of a choc female is choc/-

The genotype of a bird split to choc is Choc+/choc, and the bird MUST be male.

The genotype of a non-choc male is Choc+/Choc+
The genotype of a non-choc female is Choc+/-

Lavender is not a sex-linked gene.

The genotype of a lavender bird is lav/lav
The genotype of a bird split to lavender is Lav+/lav
The genotype of a non-lavender bird is Lav+/Lav+

With both choc and lavender, birds who are split cannot be visually discerned from those who are pure for not having the gene.

Confusing the issue with choc is dun, which has a similar appearanceand the same hobby name (chocolate), but is an autosomal incompletely dominant gene.


I would love to see comparative photos of choc or dun birds who are silver based versus ones who are gold based.

 

[Henk69]

The + sign is used for the wildtype genes, the not mutated ones
The - sign is used for the entire w-chromosome that lacks most of the genes of its companion, the Z chromosome
So no direct relation between these two symbols
The slashes in between represent the chromosomes
a//a is a genepair, also shorter notation a/a or even aa

 

[Sonoran Silkies]

+ indicates a wild-type allele; the "default" variation of the gene

An allele with a capital letter is dominant; one with a lower-case letter is recessive. Examples are Lav+ (dominant wild-type, not-lavender) & lav (recessive, lavender); S (incompletely dominant, silver) & s+ (recessive wild-type, gold); B (incompletely dominant, sexlinked, barred) & b+ (recessive wild-type, not-barred).

A dash indicates a gene that is not present due to the bird's female gender: B/- or b+/- or Choc+/- or choc/-

 

[Sonoran Silkies]

Quote:
It can also be written as (a,a)

 

[Henk69]

Quote:
It can also be written as (a,a)

Yes, but let's not...

 

[Heather08]

Bare with me, im going to have a few questions , but must do some chores first.... lol I come from the world of horse genetics and this is a bit over my head, there is no sex linked so that is something Ive got to understand better and there are new symbols being used here that Im not familiar with .... horses are so much more simple... heck mine are EE AA Crcr TOto and Ee Aa and ee aa CRcr and EE Aa... heehee anyone care to guess what color my 4 horses are? Im sooo interested in this chicken color subjects however thanks for sharin this info here.

One of my first questions is what is the explaination of this reference to "wild type"

 

[Henk69]

Quote:
Tobiano Buckskin
Bay split for chestnut and split for black
Palomino
Bay split for black

Wildtype horse is the wild przewalski horse. The + sign isn't used that much in horse genetics but if it were, then its genotype would be
E+/E+ A+/A+ cr+/cr+ to+/to+
Note that E+ is the same as "your" E, cr+ = cr, to+ = to
A+ however is not common in tame horses, but similar to A in effect. A+ is called "light bay".

The wildtype chicken is the red jungle fowl.

 

[Heather08]

Very good Henk

thats my herd. Instead of the term split we use Homozygous, is this how split is used? like EE is homozygous black and Ee obiviously heterozygous.


The A+ i dont think would be used(in horses) , in the wild form I think you might be referring to pangre(no real symbol for it) or maybe primitive marking like Dun?, there is a At that is used that is for the "near black bay" assumed to be another form of agouti, i have seen it typed as A+ but most often At.

Ok I got the wild term now, thank you .

 

[Sonoran Silkies]

split is heterozygous