Pomeranian Goose Genetics

A great goose genetic calculator I found: Goose Calculator

some notes I put together years ago, but worth sharing:

Source of Info: These are just raw notes that I have posted.If you have comments about them please feel free to email me.
Color and Pattern Variants of Geese
Poultry Breeding and Genetics
Edited by R.D. Crawford
New York  1990
Autosomal recessive white(c).  Birds of genotype c/c are entirely white with orange bill and feet and blue eyes.  Gosling down is yellow.  It is characteristic of White Chinese.  However the mutation seems not to be carried by western breeds except where it has been introduced from White Chinese.  Hence in crosses of White Chinese with white feathered western breeds, the progeny are usually found to be colored.  And thus the mutant appears to be recessive to both anser and cygnoides wild-type (C+).
Sex-linked recessive spotting (sp).  Colored plumage is restricted to the head, upper neck, back, shoulders and thighs; eyes are blue.  The term spotting is somewhat of a misnomer since the nonwhite areas retain the wild-type pattern.  This pattern has traditionally been known as pied or saddleback.  Jerome(1953, 1954, 1959)  found it in the white-feathered Emden breed, and it is characteristic of the  Grey Pomeranian.  Its status in eastern breeds needs further study.
Sex-linked dominant dilution (Sd).  White plumage in breeds descending from the greylag seems to be the result of a combination of the sex-linked genes for recessive spotting (sp) and dominant dilution (Sd), and not the result of the recessive white (c) gene.  Thus the genotype for males is Sd/Sd sp/sp and for females Sd/-sp-.  The dilution gene has the ability to lighten the spotted pattern to white.  Goslings of these breeds can be sexed with some accuracy,  males having yellowish heads and gray backs, and females having greyish heads and gray backs.  Juvenile and adult feathers show little melanic pigment although breed standards do allow for traces of gray in the back, wings, and tail of young specimens.
                The combination of solid pattern (Sp+) plus dilution (Sd) has produced the autosexing breed known as Pilgrim, in which males are white and females are gray.  The genotype of the male is Sp+/Sp+ Sd/Sd and of the female Sp+/-Sd/-.  It is assumed that two dilution alleles in the male are capable of preventing the formation of melanin pigment while in the female one dilution gene can only lighten, not whiten, the solid gray patter.  Goslings are easily sexed, males having yellowish down and females being olive-gray.  At maturity males will still show occasional gray areas on the back, wings, and tail.  Females show white areas around the bill, the upper neck, and occasionally on the breast.  The eye color for males is grayish blue and for females it is dark gray or brown.  The spotted pattern without dilution (sp/sp sd+/sd+) is a breed requirement of the Gray Pomeranian.
                Use of the sex-linked dilution Sd for autosexing was outlined by Bondarenko et al.  (1986) for crosses between gray and white breeds as well as between two white breeds.  This is a unique way to utilize sex-linked genes and concurrently to acquire heterosis in the progeny.  They found Sd to be characteristically present in Emden, Italian, Rhenish, and Slovakian White breeds.  Stasko (1970) has also used the Sd gene for autosexing of crossbred geese.  He used a white synthetic stock (Gl-Iv-f line derived from Italian and Rhein breeds)as the sire, and the colored Landes breed as the dam.
                Although a sex-linked color dilution locus (Sd) seems to have been adequately identified, further critical examination and research is needed since Jerome?s (1953, 1954, 1959) matings were made in only one direction and no F2 generation was examined.
Recessive buff (g).  This trait was reported to be allelic to wild-type gray (G+) of western breeds (Jerome, 1954).  It is expressed as fawn shade of buff.  There is no change in the feather pattern.  The eyes are brown.  It is sex-linked (Jerome, 1970).  The color is a breed requirement of American Buff, Brecon Buff, Buff Pomeranian, and Buff Toulouse.  Its action in cygnoides breeds is not known.
                The author observed a buff mutant in a flock of tame Cananda geese (Branta canadensis) in Prince Edward Island, Canada in 1987 and was informed by the owner that such color variants have been known in other flocks in the province.  There was no change in the basic pattern. 
Breast patch (Wb).  This trait is expressed as a crescent-shaped white patch on the breast.  It is not found as a standard characteristic in any present-day breeds.  Jerome (1953) classified the trait as a dominant on thebasis of an F1 generation from a White Chinese male mated with a Toulouse female, and suggested the gene symbol Wb.  Crawford (1988, personal communication) found a breast patch in the F1 offspring of an African male x Pilgrim females and it was present in some F2 birds.  The author also found it in F1 progeny from the reciprocal crosses of Pilgrim and White Chinese, but not in progeny from Pilgrim and Roman.  All of these observations suggest that breast patch originates with cygnoides breeds only.
                The work of Jerome (1953, 1954, 1959, 1970)  has provided an excellent start in describing genetics of plumage color in geese.  But much more research and observation is needed before plumage colors and patterns can be adequately described in genetic terms.
Color of bill and feet.  Bill colors in day-old goslings were observed by Jerome (1953) who related certain bill color types to specific down patterns.  He reported that the dilution gene Sd had a profound effect in reducing the melanin deposition
                Stasko (1970) reported a sex-linked gene pair, which affected color of gosling bill and feet.  The recessive gene (b)lightened the extremity colors.  It apparently is different than sex-linked dilution (Sd) which was also present in his birds.
Another Source:
Domestic Geese
Chris Ashton
1999 The Crowood Press Ltd
Ramsbury, marlborough
Wiltshire SN8 2HR
G+           Wild type gray
g              Recessive buff
Sp+         Solid Pattern
sp            Sex-linked recessive spotting
sd+         Wild type non-dilution
Sd           Sex-linked dominant dilution (Sd)    
Gray male
(G+/G+) or (G+/g)
(Sp+/Sp+) or Sp+/ sp)
Gray female
(sd+/-)                    (Sd/-) Pilgrim gray
Buff male
(Sp+/Sp+) or (Sp+/ sp)
Buff female
(G+/G+) or (G+/g) or (g/g)
(sp/sp)   or {(Sp+/sp)?unsure of results}      or {(Sp+/ Sp+)?Pilgrim white}        
(Sd/Sd)                   (Sd/sd+) color will show through white
White female
(G+/-) or (g/-)
White male (sp/sp Sd/Sd)  and white female (sp/- Sd/-)
?Goslings of these breeds can be sexed with some accuracy, males having yellowish heads and gray backs, and females having grayish heads and gray backs.?(crawford)
Gray/white saddleback male
(G+/G+) or (G+/g)
Gray/white saddleback female
Buff/white saddleback male
Buff/white saddleback female
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