Eddie Caro, 2026 MGM Distinguished Fellows Travel Award Recipient

Lodge Lab
2026 Gordon Research Conference on Cellular and Molecular Fungal Biology
June 21–26, 2026

Abstract: 
Cryptococcus neoformans adapts to host environments through dynamic morphogenesis and cell-wall remodeling. Many virulence‑related traits remain difficult to characterize because they are weakly expressed or functionally redundant under standard laboratory growth conditions. Routine gene-deletion screens usually assess morphology only at the colony level, leaving stress-dependent cellular phenotypes largely undetected. We therefore developed a high‑throughput single‑cell microscopy screen to profile a 4,800‑mutant deletion library under host‑like conditions, allowing direct detection of conditional defects. This method identified approximately 170 mutants with stress-dependent morphological abnormalities, including CNAG_05613, which encodes the conserved Dopey family protein Dop1. Deletion of DOP1 led to enlarged cells, defective budding and cytokinesis, and problems with cell separation; phenotypes that were absent under standard growth conditions but were rescued by genomic complementation. These abnormalities resembled those seen in apt4Δ mutants, and AlphaFold-Multimer modeling suggested a specific interaction between Dop1 and Apt4. Several assays indicated disrupted phosphatidylethanolamine (PE) asymmetry in the dop1Δ mutant, as evidenced by increased sensitivity to duramycin, ethanolamine-induced defects, and lithium-induced membrane stress. Collectively, the data identify DOP1 as a regulator of Apt4‑mediated aminophospholipid asymmetry that becomes essential under host‑like stress. More broadly, this study demonstrates that condition-specific single-cell phenotyping can uncover membrane vulnerabilities that remain hidden in traditional colony-based laboratory screens.