Albinism in White Leghorn chickens

Area of Science:

• Avian genetics
• Molecular biology
• Pigmentation genetics

Background:

• A mutation causing oculocutaneous albinism appeared in a closed Single Comb White Leghorn line.
• The line has been maintained since 1949, with the mutation first observed in 1988.
• Understanding albinism mutations is crucial for poultry breeding and genetic research.

Purpose of the Study:

• To characterize a newly identified albino mutation in White Leghorn chickens.
• To determine the genetic locus and allelic relationship of the Wisconsin albino (WIA) mutation.

Main Methods:

• Pedigree analysis and genetic crosses were performed.
• The WIA mutation was tested against known albinism alleles (cre and ca) at the C locus.
• Phenotypic segregation patterns were observed in offspring from specific crosses.

Main Results:

• The WIA mutation was mapped to the C pigment locus.
• Mating WIA with cre/cre birds revealed incomplete recessiveness, indicating a relationship to the cre allele.
• No segregation was observed when WIA was mated with ca/ca birds, suggesting allelic identity or similarity.

Conclusions:

• The Wisconsin albino (WIA) mutation is located at the C pigment locus in chickens.
• Genetic data strongly suggest that WIA is identical or allelic to the previously identified tyrosinase-negative recessive albinism (ca) mutation.
• This finding clarifies the genetic basis of albinism in this poultry line and contributes to the understanding of the C locus.