The genetics of frizzling in fowls

Abstract

1. An investigation has been conducted to determine the mode of inheritance of frizzling in the domestic fowl and to substantiate or disprove the current theory that homozygosity for frizzling is lethal. 2. One hundred and forty chicks classified from matings of frizzled x normal fowls exhibited a 1:1 ratio of each class. 3. Three hundred and twenty -six chicks classified from matings of Frizzle x Frizzle approach a 3 :1 ratio of Frizzle to normal closely enough to be within the limits of fluctuations due to sampling. 4. Offspring of normally feathered fowls extracted from matings of Frizzle x normal were all normal. 5. Incubation records of 758 eggs fail to show any evidence of a zygotic lethal factor believed to be associated with frizzling being operative during embryonic development. 6. The possibility of a gametic lethal is discussed and discarded. 7. It is concluded that frizzling is a monofactorial dominant character. 8. The hypothesis is suggested that the reputed inability of frizzled fowls to breed true arises from a preference by the fancier for the phenotype exhibited by the heterozygous individual resulting in the exclusion from the breeding pen of all the homozygous individuals. 9. A critical experiment to prove or disprove this hypothesis is under way.PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH. SESSION 1928 -1929. VOL. XLIX -PART II -(No. 9). On the Relation of Fertility in Fowls to the Amount of Testicular Material and Density of Sperm Suspension. By F. B. Hutt,PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH. SESSION 1928 -1929. VOL. XLIX -PART II -(Nos. 10, 11, and 12). X.-XII.- Studies in Embryonic Mortality in the Fowl. I. The Frequencies of Various Malpositions of the Chick Embryo and their Significance. By F. B. Hutt II. Chondrodystrophy in the Chick. III. Chick Monsters in Relation to Embryonic Mortality. By F. B. Hutt, and A. W. GreenwoodTHE VETERINARY JOURNAL, Vol. 84, No. 11, pp. 579 -584. Potentially Fatal Fatigue of Cervical Muscles of the Fowl Resulting from an Excessively Large Comb. By F. B. HUTT,SEX DIMORPHISM AND VARIABILITY IN THE APPENDICULAR SKELETON OF THE LEGHORN FOWL F. B. HUTT