Table 1.

Fitness Scores for the Top 25 Mutants Identified as Significantly Sensitive to the Dieldrin IC₂₀ (460μM) After 15 Generations of Growth

Log2 values			Deleted gene	Description
25% IC20	50% IC20	100% IC20
−3.90	−4.95	−6.80	IRA2	GTPase-activating protein; negatively regulates Ras
−4.00	−4.40	−6.10	GYP1	GTPase-activating protein; involved in vesicle docking
−5.60		−5.65	BAP2	High-affinity leucine permease
−3.75	−4.85	−5.60	PDC1	Major of three pyruvate decarboxylase isozymes
−3.10	−3.95	−5.25	YJL120W	Dubious ORF; partially overlaps the verified gene RPE1
−4.90	−4.50	−5.05	PDR5	Multidrug transporter
−4.70	−5.20	−5.00	YCR007C	Putative integral membrane protein
−3.10	−3.10	−4.90	IRS4	Regulates PtdIns(4,5)P2 levels and autophagy
−1.30	−1.60	−4.90	SOK2	Regulator of PKA signal transduction pathway
−1.65	−1.45	−4.85	TCB3	Lipid-binding protein
−3.80	−5.30	−4.80	SLT2	MAPK involved in cell wall integrity and cell cycle progression
−4.90	−4.90	−4.80	YML079W	Unknown function; structurally similar to plant storage proteins
−4.15	−4.45	−4.70	TIM18	Component of the mitochondrial TIM22 complex
−2.00	−2.40	−4.70	OPI3	Phospholipid methyltransferase
−3.20	−3.40	−4.60	SIS2	Negative regulatory subunit of protein phosphatase 1
−2.55	−2.35	−4.60	SCJ1	Homolog of bacterial chaperone DnaJ
−4.20	−3.50	−4.50	SIW14	Tyr phosphatase; involved in actin organization and endocytosis
−2.10	−2.55	−4.45	CNB1	Calcineurin B; the regulatory subunit of calcineurin
−2.30	−2.75	−4.35	OSH3	Oxysterol-binding protein; functions in sterol metabolism
−1.90	−2.85	−4.25	UFD2	Ubiquitin chain assembly factor (E4)
−3.05	−4.90	−4.10	IMP2′	Transcriptional activator; maintains ion homeostasis
−3.05	−2.75	−4.10	BRE5	Ubiquitin protease cofactor; forms complex with Ubp3p
−4.00	−4.30	−4.00	SAP4	Protein required for function of the Sit4p protein phosphatase
−2.90	−3.60	−4.00	ECM30	Nonessential protein of unknown function
−2.60	−2.40	−4.00	BST1	GPI inositol deacylase; negatively regulates vesicle formation

Note. Fitness scores quantify the requirement of a gene for growth and are defined as the normalized log₂ ratio of the deletion strain’s growth in the presence versus absence of dieldrin. A total of 427 genes were important for fitness (i.e., had negative fitness scores) in at least one dieldrin treatment. Supplementary table 1 contains a list of all genes identified as significant by DSSA.