Ciao, because gold-Silver is a sex-linked gene (male have 2 dosis and females have only 1 dosis)
Your gold male have 2 dosis gold = s+/s+ your female have 1 dosis Silver = S/-
When you cross these you become this :
Male chicks :
ERER CoCo DbDb PgPg MlMl Cha+Cha+ mh+mh+ di+di+ Ig+Ig+ cb+cb+ i+i+ bl+bl+ Lav+Lav+ C+C+ Mo+Mo+ b+b+
Ss+ Choc+Choc+
Female chicks :
ERER CoCo DbDb PgPg MlMl Cha+Cha+ mh+mh+ di+di+ Ig+Ig+ cb+cb+ i+i+ bl+bl+ Lav+Lav+ C+C+ Mo+Mo+ b+-
s+- Choc+-
So when all chicks are gold they must be all females !!!
If you had male chicks they must be S/s+ = Golden (is Silver with a little golden shine because Silver is Dominant over gold)
which can be confused for lemone !
Your friend couple had to be both split (= carrier) for lemone = Ig+/ig. This is a recessive red-pigment diluting gene so it will reveal itself only when in double dosis = ig/ig. In +- 25% of the chicks of her cross will come together the 1 dosis "ig" of the mother with the 1 dosis "ig" of the father resulting in this :
Male chicks :
ERER CoCo DbDb PgPg MlMl Cha+Cha+ mh+mh+ di+di+
igig cb+cb+ i+i+ bl+bl+ Lav+Lav+ C+C+ Mo+Mo+ b+b+
s+s+ Choc+Choc+
Female chicks :
ERER CoCo DbDb PgPg MlMl Cha+Cha+ mh+mh+ di+di+
igig cb+cb+ i+i+ bl+bl+ Lav+Lav+ C+C+ Mo+Mo+ b+-
s+- Choc+-
[Modificato da Danny_57 18/06/2012 11:34]