Genetics of Partridge?

[SusanJoM]

This is one gorgeous silkie

https://www.backyardchickens.com/forum/viewtopic.php?pid=803085#p803085

So tell me, is Partridge a color scheme all of its own? I am smitten...

I've got blacks and blues and splashes and hopefully even some young cuckoos, but....that is just a beaut !!!!

Susan

 

[tadkerson]

Susan,

In the US, partridge is a pattern called penciling. There are three genes that are needed by a bird to make the partridge pattern, the eb or brown gene , which at one time was called partridge, the sex linked gold gene (s+) and the pattern gene (Pg). There are some other genes needed to make very good penciling but they are not documented. In Europe partridge means wild type . I forget if it means the same in Australia.

Take a look at a partridge rock and you will see the pattern.

Blacks, blues and splashes normally do not have the brown gene. Black Wyandottes are an exception- they are eb. The pattern gene could be found in blacks and blues and splashes. I have a barnevelder that is almost black- she only shows some red shafting on her feathers; all of here sisters were double laced. I thought she was a black sex link until I saw her yellow legs. I sold all my barnevelder. She has the pattern gene in her but she is brown at the E locus. I am going to cross her with an eb rhode island red I have and see what happens. I would like to know why she is black. Rhode island red are usually wheaten.


Even if a bird had the pattern gene and was black you would never know that the bird had the gene. But it will show up as lacing on blue birds.


Tim

 

[hinkjc]

Tim, great explanation! Can you help me with another question? When folks call a smutty buff bird a "partridge" - is one of those genes factoring in to make the smut color on a buff? Or are folks just using the wrong terminology and it's just a poor buff?

Jody

 

[tadkerson]

The poultry world has all kinds of terminology they use- some breeders have terminology they use just for their breed and variety. Even in journal papers the terminology changes over time. What ever vocabulary helps people understand a concept it is ok with me. That is why pictures are so great- the picture communicates the genetics.

If you are talking about slkies, they do not show color patterns like other birds because of their unique feathers. Buff is caused by genes that are completely different than the genes that cause partridge in a bird. So, a partridge is not a smutty buff. I hope I understood your question. If not, let me know.

Tim

 

[SusanJoM]

So, I've been trying to read the information here

http://home.ezweb.com.au/~kazballea/genetics/theory.html

and trying to put it together with what you (Tim) said about the three genes required for Partridge.

Am I correct then to assume that the brown (eb) is at the E locus and would have to be present in both parents (I'm guessing the lower case means its recessive) to be expressed. And the gold is sex-linked, so it's carried on the Z?
And the patterned is either present or not present at another locus, rather than one of many possibilities at that other locus?

Am I getting close?

Susan

 

[hinkjc]

Quote:
Thanks Tim! That's exactly what I was thinking, so I never understood when folks said "this is a buff partridge" or say they hatched a partridge bird out of buff stock when it is actually the typically dark buff. Appreciate your help.

Sorry Susan for jumping in on your post. Good luck with understanding partridge..they are beautiful birds.

Jody

 

[SusanJoM]

Quote:
Hey, Jody, every question asked and answered helps....glad you asked that one...

Susan

 

[tadkerson]

Quote:
Susan you are doing great,

You need to know some more about the E locus. There are 9 different genes that can be found at the E locus. They are Extended black (E), birchen (E^R), Dominant wheaten (e^wh), wild type e^+, brown (e^b), speckled ( e^s), butter cup (e^bc) and recessive wheaten (e^y). I have listed them in the order of dominance with E being the most dominant and recessive wheaten being the most recessive.

The partridge pattern works best on eb females. Some of the other E locus alleles do not have enough black stippling to form a pattern. So you do not want them in a chicken that is partridge. The pattern gene takes the stippling and forms the pencil marks that are on the feather. Normally the stippling would be scattered all over the feather. The pattern gene is at its own locus with another gene for not forming patterns pg+. Pattern gene is Pg and no pattern gene is pg+.

Yes the gold gene is found at the silver locus on the Z chromosome. So a chicken can have an S for silver or an s+ for gold.

Tim