Validation of the S. cerevisiae–specific essential gene VTC4. (A) Mapped chromosomal insertion positions are plotted across Chromosome XII. Haploid inserts are indicated in red; diploid inserts, in blue; and overlapping inserts, in purple. Genes indicated across the top are outlined according to predicted dispensability and filled in if confirmed. Light pink filling indicates a gene that is essential in S. cerevisiae and nonessential in S. uvarum (confirmed NE_E). (B) Tetrad analysis of a heterozygous vtc4Δ strain displaying viable segregants with the vtc4Δ allele in S. uvarum plated on YPD and G418. (C) Tetrad analysis of a heterozygous vtc4Δ allele in S. cerevisiae resulting in inviable segregants. (D) Table indicating the insertion ratio (number of haploid inserts by the number of diploid inserts) per gene. The final column lists the predicted classification: (NE) nonessential; (E) essential; (N/A) no data.
