HeLa cells inducibly expressing untagged Cidec were vitrified, screened for enlarged LDs in close proximity by cryo-FM, thinned by cryo-FIB milling, and imaged by cryo-ET. The shape of the LDs is deformed where two LDs are closely apposed. The different observed morphologies are classified as follows: protrusion of one LD into the other LD, resulting in an indentation. First column from left: virtual slices through tomograms acquired at areas where LDs are in close proximity (Videos S5–S7). Dashed squares indicate areas corresponding to magnified images in third column. Second column: segmentation models of LDs and membranous organelles in proximity of LDs. Pink and magenta shades, LDs; yellow, OMM; green, IMM; turquoise, ER; blue, other membranous organelles (Other). Third column: close-ups of interfaces between LDs (different virtual slices than in the first column). Fourth and fifth column: close-ups of monolayers at the interface (fourth column; in A and C this is the same virtual slice as in the third column) and outside the interface (fifth column). Scale bars, 150 nm in first column, 100 nm in third column, 25 nm in fourth and fifth columns.
