Genetic Basis of Erminette Pattern in Fowl

Question:

What is the genetic basis of the erminette pattern in fowl? How would you test your hypotheses?

Answer:

1. The erminette pattern in fowl is likely controlled by a codominant gene.

2. If the erminette pattern is controlled by a codominant gene, you would expect to see a 1:2:1 ratio of erminettes:black:pure whites.

Explanation:

The genetic basis of the erminette pattern likely follows a sort of complex inheritance pattern that isn't purely dominant/recessive or straightforward.

This is because the erminette fowl, featuring a mix of black and white feathers, appears to be a type of intermediate phenotype between the black and white fowls.

1. In this scenario, the erminette pattern isn't a blend of the two colors, but instead a separate phenotype that can be inherited. The ratio derived from the given data (22 erminettes, 14 blacks, and 12 whites) is near to a 9:3:3:1 phenotypic ratio, suggesting a dihybrid cross - a fundamental principle of Mendelian inheritance.

2. To test this hypothesis, breed the F1 generation with each other or back with the parent generation and observe the progeny's feather color. According to Mendelian inheritance, a typical dihybrid cross in the F2 generation would produce a 9:3:3:1 ratio of phenotypes (in this case, erminettes:black:white). Comparing the actual data from the resultant crosses with these expectations can give us a clue about the underlying genetics.