![]() It was followed by sib mating of the all wild-type G1 quail to produce G2 and G3 pedigreed progeny and selection of the few rusty G4 birds. The quail line with the rusty plumage color was started in 2000 from a founding base (G0) made of a single rusty female bred to a wild-type male from another origin. ![]() In all instances, inheritance of the trait was similar for both sexes, and heterozygotes CU*C/CU*N had normal plumage structure, indicating that the locus CU was autosomal and the mutation was recessive. Following the gene nomenclature proposed for the chicken, the locus for this new mutation was named CU, and the symbols of the allele responsible for the curly mutation and of the normal allele at this locus were CU*C and CU*N, respectively. The difference between normal and curly adults (Figure 2) is not as marked as for other feather structure mutations, like porcupine, for example. The expression of the trait is variable, however, and the penetrance of the curly mutation appears to be incomplete. This phenomenon is best observed around 10 days of age and is associated with the curly growth (Figure 1). In curly chicks, the calamus of the growing wing feathers are not independent from one another, but they are connected through the follicle walls which appear to be joined together. No differential survival was observed in curly quail after hatching, but the hatching rate in the fixed line at G5 under pool mating was only 34%, mainly because some females did not get mated under this type of mating. Starting in G3, only quail for which the curly phenotype observed at 10 days of age was expressed most strongly were kept for breeding. The quail line with the curly feathers was developed in 2001 from group mating 6 founding (G0) curly quail. Growth of the F2 quail was also monitored and compared according to their phenotype for the two plumage mutations. In the present work, a new feather structure phenotype (curly) and a new plumage color (rusty) were described, and their mode of inheritance and linkage were studied in two successive generations (F1 and F2) from an F0 made of eight quail with curly feathering and eight birds with rusty plumage. Moreover, the fact that some plumage colors, like "lavender", are common to several avian species is an added incentive to enrich the panel of characterised Japanese quail mutations as potential tools for comparative studies among bird species. ![]() Interestingly, some of the mutations described in quail, like the sex-linked "roux" and the lethal "yellow" mutations still have no known homologues in the chicken. ![]() This knowledge has already been put to use for running comparisons between chicken and quail based on plumage genetics, and for tagging commercial quail lines with a visible plumage trait, like the "fawn" mutation, or with an auto-sexing mutation like the "roux" gene. Since the last compilation of plumage mutations of Japanese quail, new loci were described ], linkage and epistasis relationships were explored, and some genes were recently mapped. In the recent past, a special attention was given to the study of its plumage, and several major genes have been described. Japanese quail is both a model animal in biology and a bird used for meat and egg production under a large variety of settings. The curly line is a new model which may be used for further work on the growth of the feather, and the rusty mutation is a new addition to the panel of plumage mutations available for comparative studies in poultry, and more generally among avian species. The curly mutation has also a positive effect on body weight at 5 weeks of age. Both characters are determined by autosomal recessive mutations which are independent. Two lines breeding true for the curly or the rusty phenotype were developed. Rusty plumage color results from the replacement of the wild-type plumage pattern on the tip of the feather by a reddish coloration, but the pigmentation of the bottom part of the feather is not affected. ResultsĬurly feathers result from abnormal early growth caused by transient joining of follicle walls of adjacent feathers around 10 days of age, but the expression of the trait is variable. There are only few plumage mutations reported in quail, and the present work describes a new color variant "rusty" and a new feather structure "curly", and their heredity from an F1 and F2 segregation experiment. The genetics of plumage of Japanese quail is of interest both from a biological standpoint, for comparative studies between avian species, and from a zootechnical standpoint, for identifying commercial selection lines or crosses.
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