Extensive redundancy underlies robustness to tRNA gene deletion.

<p>(A) Schematic representation of the genetic interactions within and between tRNA families. Families are denoted by dark grey circles and grouped (black dashed line) according to their tRNA copy number. Each family is denoted by its anti-codon and amino-acid. A protein-coding gene i.e. <i>TRM9</i> is denoted by a grey box. Each filled circle indicates a tRNA deletion strain. The lines connecting the deletion strains denote a co-deletion of these genes (a multi-tRNAs deletion strain). The color of the filled circles and lines denote the severity of the growth phenotype for the respective strain: blue for normal growth, purple for impaired growth (worse than wild-type) and red for lethality. (B) Epistasis values for multi-tRNAs deletion strains which contain the deletion of <i>tL(GAG)</i> and either: one <i>tL(UAG)</i> gene, two <i>tL(UAG)</i> genes, <i>tL(CAA)</i> (which is a tRNA of different Leucine family), and <i>tW(CCA)</i> (which is a non-Leucine tRNA) as controls. (C) Epistasis values for multi-tRNAs deletion strains which contain the deletion of <i>trm9</i> with: the singleton <i>tR(CCU)</i>, and <i>tR(ACG)</i> which is a tRNA of different Arginine family and <i>tW(CCA)</i> which is a non- Arginine tRNA as controls. In both (B) and (C) epistasis values of the relative growth yield and growth rate are indicated in grey and green respectively. Data is presented as mean of 3 biological repetitions +/− SEM.