Design and practice of educational experiments on genetic epistasis

Area of Science:

• Genetics
• Molecular Biology
• Biochemistry

Background:

• Genetic epistasis describes how gene interactions influence phenotypic traits.
• The adenine biosynthesis pathway in Saccharomyces cerevisiae (baker's yeast) is a model system for studying gene function.
• Mutations in ADE2 lead to a red phenotype due to intermediate accumulation, while mutations in upstream genes like ADE8 can mask this phenotype.

Purpose of the Study:

• To enhance student understanding and practical application of genetic epistasis.
• To demonstrate gene interactions and their effect on phenotypes using yeast genetics.
• To provide hands-on experience with CRISPR-Cas9 genome editing and yeast manipulation.

Main Methods:

• Utilizing Saccharomyces cerevisiae as a model organism.
• Employing CRISPR-Cas9 genome editing technology for gene knockouts.
• Creating single (ade2Δ) and double (ade2Δade8Δ, ade2Δade1Δ) knockout yeast mutants.

Main Results:

• Observation of phenotypic changes in yeast mutants, specifically color shifts from white to red and back to white.
• Demonstration of epistasis where mutations in ADE8 mask the red phenotype caused by ade2Δ.
• Successful generation of specific gene knockout strains for educational purposes.

Conclusions:

• Students gain a profound understanding of how genes determine phenotypes and the concept of epistasis.
• Mastery of fundamental yeast genetic techniques is achieved, enhancing experimental design skills.
• The experiment significantly benefits students' future research work and academic development.