Selectable markers in Saccharomyces cerevisiae: Which of the following are commonly used auxotrophic markers for yeast molecular genetics?

Introduction / Context:
Yeast genetics routinely uses auxotrophic markers to select transformants on defined media. Recognizing standard markers speeds vector choice and experimental design in cloning and genome engineering.

Given Data / Assumptions:

• Common yeast lab strains carry auxotrophic mutations (e.g., his3Δ, ura3Δ, trp1Δ).
• Complementation with a wild-type marker gene restores growth on selective media.

Concept / Approach:
HIS3 complements histidine auxotrophy, URA3 complements uracil auxotrophy, and TRP1 complements tryptophan auxotrophy. Vectors often include one of these markers to select for successful transformation, and LEU2 is another common marker (not exclusive). Therefore, HIS3, URA3, and TRP1 are all correct examples of commonly used markers.

Step-by-Step Solution:

Verification / Alternative check:
Yeast vector catalogs and classical protocols list HIS3, URA3, TRP1, LEU2, and others as routine markers.

Why Other Options Are Wrong:

• Any single marker alone is incomplete; multiple are in common use.
• “LEU2 only” ignores the prevalence of HIS3/URA3/TRP1 markers.

Common Pitfalls:
Assuming one marker dominates; in practice, marker choice depends on host genotype and experimental design.

Final Answer:
All of these