An autosomal recessive blind mutant in the chicken

Area of Science:

• Genetics
• Ophthalmology
• Molecular Biology

Background:

• Inherited retinal dystrophies can lead to blindness.
• The genetic basis for many forms of blindness remains unknown.
• Rod and cone photoreceptor cells are crucial for vision.

Purpose of the Study:

• To identify the genetic cause of a specific type of inherited blindness.
• To investigate the inheritance pattern of the blindness-causing gene.
• To determine if the mutation was induced by ethyl methanesulfonate (EMS).

Main Methods:

• Pedigree analysis to track inheritance of the blindness trait.
• Genetic linkage analysis to map the causative gene.
• Examination of descendants from a male with a Z chromosome and chromosome 3 translocation.

Main Results:

• A single autosomal recessive gene, designated 'rc', controls the blindness.
• The mutation was identified in the second generation of descendants.
• Linkage analysis between the blindness locus and the chromosome 3 translocation breakpoint was not significant.

Conclusions:

• The identified blindness is inherited in an autosomal recessive pattern.
• The 'rc' gene is responsible for the lack of rods and cones.
• The mutation's origin as EMS-induced remains unproven.