Any updates on breeding Opals?
BBB, were you able to test breed Opal with known recessive whites (that couldn't have I Dominant White too)?
Anyone bred the Opal gene on to wild-type (BBRed), developed a Opal-breasted Red version?
Anyone test bred Opal with homozygous Dun (Fawn-breasted Red)?
Anyone test bred Opal with homozygous I - Dominant White from Red Pyles, then tried to segregate out wild-type black versions?
I know Ron test bred Opal with a homozygous Dominant White (I/I) hen, & showed very strong evidence that Opal was an allele of the I locus (no blacks segregated with F2, nor F1 backcrossed to Opal).
If Opal was not an allele of the I dominant white locus, you would expect the following to segregate from Ron's Opal x F1 dominant white (I/?) backcross:
op = opal
25% White (maybe opal splashes?): (1/4) op/op (Opal), , I/i+ (Dominant White),
25% Opal: (1/4) op/op (Opal), , i+/i+ (non dominant white),
25% White (maybe black splashes): (1/4) Op+/op (non-opal), , I/i+ (Dominant White),
25% Black (1/4) Op+/op (non-opal), , i+/i+ (non dominant white),
Which is 1/2 white, 1/4 opal, 1/4 black.
If Opal was an allele of the I dominant white locus, & was recessive to I dominant white allele, you would expect the following to segregate from Ron's Opal x F1 dominant white (I/?) backcross:
i^op = opal
i^op/i^op X I/i^op =
50% White: (1/2) I/i^op (Dominant White, carrying opal),
50% Opal: (1/2) i^op/i^op (opal),
Which is 1/2 white, 1/2 opal, (no blacks).
This is what Ron produced Opal X F1 white (3 different breeding pens):
- 11 white males and females and 14 Opals No Blacks.
- 5 Whites and 2 Opals
- 8 Opals and more Whites.
Take out the 3rd test breeding (don't have the white numbers), & that is:
16 whites,16 opals, no blacks (from 32 offspring).
If Opal wasn't an allele of the I locus, the expected probabilities (with 32 offspring) would be approx:
16 white, 8 opal, 8 black.
Include the fact that no blacks segregated from Ron's 28 F2 either (& that I excluded the 3rd BC1 results - no blacks there too), that is very strong evidence that Ron's Opal mutation is an allele of the I Dominant White locus.
This needs to be confirmed with test breeding of Opal breasted Red (opal on wild-type) x homozygous I/I Red Pyle (& proven not a carrier of c recessive white) (rule out the possibility that Ron's I/I dominant white hen was a carrier of c too), or by test breeding Opal with I^D/I^D homozygous dun (proven not a carrier of c).
Also would be great if someone developed opal on wild-type (Opal breasted Red) to be certain of the effects of the Opal mutation on both eumelanin (black) and phaeomelanin (gold/red).