Diamond Firetail Finch Mutation Genetics
Posted: 11 Apr 2017, 17:08
I posted this question on the American finch forum but received no replies. I hope keepers of Diamonds on this forum can help me out:
My pair of phenotypically normal Diamond Firetail finches have, in their first clutch, produced a light coloured chick; what a surprise considering the parents of this pair are also phenotypically normal. I guess they both have "split something" hiding in their genes. This chick (see image below) has fledged and appears to be what we call a Silver mutation here in Japan.
In any case I just realised I have little to no knowledge of Diamond Firetail mutation genetics, and a search of the Internet has turned up very little concrete information. What I am searching for is a list of mutations and, in particular, their modes of inheritance (sex-linked, autosomal, etc.). I would also like to know how the different mutations interact, i.e., do they affect the same gene allele (like a Gouldian's chest colour gene pair expressing a paired combination among purple, lilac, and white), do they affect different alleles independently (i.e. for the Star Finch, the Fawn and Cinnamon genes are separate and operate independently, and thus a Star Finch can be both phenotypically fawn and cinnamon), or do they affect different alleles but dependently (like the Gouldian's Yellow head gene being controlled by the separate Red-Black head gene).
So far the list of Diamond Firetail mutations I've gathered is:
Yellow Tail: said to be autosomal recessive.
Fawn: one site says sex-linked recessive, while another states autosomal recessive. The veterans here say a Diamond's fawn is autosomal so I'm going with that: https://www.aussiefinchforum.net/viewtopic.php?t=13615
Cinnamon: said to be sex-linked recessive.
Isabel: black and red markings remain intact, but the bird otherwise becomes diluted so the head is a pale silver and the back is a grey-brown. Said to be sex-linked.
Pastel (Europe): said to be autosomal recessive. Seems to be the same as Silver phenotypically.
Pied: ??
Silver (Japan, Australia): looks the same as Europe's "Pastel" but the talk here is that it is sex-linked rather than autosomal.
White: ??
What I would like to ask the forum is:
(1) Are the above classifications (sex-linked or autosomal) correct?
(2) Are pied, silver, and white, sex-linked or autosomal?
(3) How do fawn, cinnamon, isabel, pastel, silver, and white interact? How many alleles are affected here? For several mutations affecting the same allele, which is dominant? I.e., is it possible to have a fawn and silver Diamond (like a Star finch's fawn + cinnamon)?
It is possible that some of the mutations I've mentioned above are in reality the same mutation. For example, it would appear that the Silver mutation we have here is, at least phenotypically, the same as the European "Pastel" mutation (see http://www.prachtvinkenforum.nl/viewtop ... f=3&t=1057 for an example) and the "Opal" mutation in Spain, but I guess it is also possible the mode of inheritance is different (i.e. sex-linked vs autosomal). The description I found for Isabel suggests it is different to both fawn and cinnamon because the "blacks remain". But the images of Isabel Diamonds from the Netherlands show what appear to be the cinnamon mutation: http://www.ton-albers.nl/diamantvink.htm (the top right-hand image), so perhaps Isabel is simply cinnamon afterall.
Anyway, can anybody shed some light on the subject please? I thank you in advance.
Ross
My pair of phenotypically normal Diamond Firetail finches have, in their first clutch, produced a light coloured chick; what a surprise considering the parents of this pair are also phenotypically normal. I guess they both have "split something" hiding in their genes. This chick (see image below) has fledged and appears to be what we call a Silver mutation here in Japan.
In any case I just realised I have little to no knowledge of Diamond Firetail mutation genetics, and a search of the Internet has turned up very little concrete information. What I am searching for is a list of mutations and, in particular, their modes of inheritance (sex-linked, autosomal, etc.). I would also like to know how the different mutations interact, i.e., do they affect the same gene allele (like a Gouldian's chest colour gene pair expressing a paired combination among purple, lilac, and white), do they affect different alleles independently (i.e. for the Star Finch, the Fawn and Cinnamon genes are separate and operate independently, and thus a Star Finch can be both phenotypically fawn and cinnamon), or do they affect different alleles but dependently (like the Gouldian's Yellow head gene being controlled by the separate Red-Black head gene).
So far the list of Diamond Firetail mutations I've gathered is:
Yellow Tail: said to be autosomal recessive.
Fawn: one site says sex-linked recessive, while another states autosomal recessive. The veterans here say a Diamond's fawn is autosomal so I'm going with that: https://www.aussiefinchforum.net/viewtopic.php?t=13615
Cinnamon: said to be sex-linked recessive.
Isabel: black and red markings remain intact, but the bird otherwise becomes diluted so the head is a pale silver and the back is a grey-brown. Said to be sex-linked.
Pastel (Europe): said to be autosomal recessive. Seems to be the same as Silver phenotypically.
Pied: ??
Silver (Japan, Australia): looks the same as Europe's "Pastel" but the talk here is that it is sex-linked rather than autosomal.
White: ??
What I would like to ask the forum is:
(1) Are the above classifications (sex-linked or autosomal) correct?
(2) Are pied, silver, and white, sex-linked or autosomal?
(3) How do fawn, cinnamon, isabel, pastel, silver, and white interact? How many alleles are affected here? For several mutations affecting the same allele, which is dominant? I.e., is it possible to have a fawn and silver Diamond (like a Star finch's fawn + cinnamon)?
It is possible that some of the mutations I've mentioned above are in reality the same mutation. For example, it would appear that the Silver mutation we have here is, at least phenotypically, the same as the European "Pastel" mutation (see http://www.prachtvinkenforum.nl/viewtop ... f=3&t=1057 for an example) and the "Opal" mutation in Spain, but I guess it is also possible the mode of inheritance is different (i.e. sex-linked vs autosomal). The description I found for Isabel suggests it is different to both fawn and cinnamon because the "blacks remain". But the images of Isabel Diamonds from the Netherlands show what appear to be the cinnamon mutation: http://www.ton-albers.nl/diamantvink.htm (the top right-hand image), so perhaps Isabel is simply cinnamon afterall.
Anyway, can anybody shed some light on the subject please? I thank you in advance.
Ross