Self Blue (lav gene) shows up unexpectedly?

[Sonoran Silkies]

Quote:
Since she is a solid blue, there is no way to tell that she doesn't have cream; there simply isn't any gold to dilute and make cream's presence known. I think if you bred her to a BCLB or even CLB you would find that she had passed it to her offspring.

Is the shaft on the bottom side of the feather also dark? Or is it light coloured?

 

[Krys109uk]

Hi Laura,
Seems a real mystery, in particular as you know precisely the bird's ancestry.
If both parents were cream, I don't suppose they'd have lost ig/ig you just can't see it.

 

[Sonoran Silkies]

I am wondering if melanizers and e^b might be at work? Doesn't seem like it could be E since that is far more dominant than the e+ that she should be.

 

[Pathfinders]

Ok, you've lost me now.

When bred back to her father, at least one chick showed up as a proper BCLB.

I don't have the bird in my possession, she's three hours north at her owners house. And I have no idea what you mean when you say "I am wondering if melanizers and e^b might be at work? Doesn't seem like it could be E since that is far more dominant than the e+ that she should be."

 

[Krys109uk]

I am wondering if melanizers and e^b might be at work? Doesn't seem like it could be E since that is far more dominant than the e+ that she should be.

I wondered whether the male might have been ER as the males can look similar but as they are Laura's birds & she has been breeding the line for so long she would have known about it by now.

I wondered about eb blacks, but I don't know enough. I had eb black leghorns but never crossed them with any e+ birds.
Even so doesn't it seem unlikely that a recessive trait would be in a line for 20 years & never have two, possibly distantly, related birds carrying the recessive trait coming together in the breeding pen?

 

[AHappychick]

wow beautiful color I say have your friend make as many as possible.

 

[Sonoran Silkies]

Sorry, I thought you were more well versed in the genetics behind the varieties.

The most important gene towards determining variety is probably the variation (allele in genetics terminology) of the extended black (E) gene. E has a number of variations as compared with blue and cream which each have two variations (blue & not-blue, cream & not-cream).

Light brown (with and without blue and/or cream) is based upon the e+ (wildtype) allele. The only alleles more recessive are e^b (brown) and E^Wh (wheaten) when some combination of melanizers are present.

E is the most dominant of the alleles, but would show up in the parent as a solid (or nearly so) coloured bird. Ditto for E^R (birchen). E^Wh is next in line (usually) and would give a wheaten-based bird. This wouldn't be as obvious on the cock, but female offspring would be wheaten coloured. Next in dominance is the e+ allele which is the base for the variety. e^b comes next.

A bird who is e+/e^b would have the appearance of e+. However, if two birds are e+/e^b, 25% of their offspring would be e^b/e^b. Generally, this would give a bird not too different in appearance to one who is e+/e+, although females would lack the salmon breast. If you add melanizers (which are not well identified/researched), you can create a solid coloured bird. Presumably some could be passed on by each parent, with only a small percentage of birds receiving sufficient to make that solid colouring.

If your pullet is lavender, that still doesn't explain the loss of pattern--it would just further dilute all colouring, but hte pattern would still be there.

 

[Pathfinders]

Actually, it's likely that the two birds are not distantly related, it's possible they are aunt and nephew (again, need to get the legbands #s from Jeff.)

Regardless, I have talked him into hatching every single egg the pullet lays (bred to her father) as well as those her mother lays (the breeding that produced her.) We'll see what we get. Once some of the little males are big enough, we'll breed them to her too (would prefer her sons, but might try her full sibs just to see.)

Must go build more pens now...

 

[Sonoran Silkies]

Quote:
That's the difficulty, and why I am thinking that it there has to be more than one gene at work.

A different alternative is a new mutation, but I'm not sure there is enough evidence to support that.

Laura, did her siblings mature to also being solid coloured birds? They look too dark to be lavender; same with her chicks. How have they matured (if they have)?

The reason I have asked about feather shafts is that that is a way to tell andalusian blue from lavender.

Suze

 

[Pathfinders]

The pictures of her siblings were taken yesterday, so no, not mature yet.

I'll ask Jeff to take some more pics of top and bottom of feather shafts.

Thanks everyone!