Micronuclear envelopes in Kif18a mutants are stable in healthy tissue but display incomplete lamin A/C recruitment in tumor cells. (A) Representative images of nuclear envelopes for primary nuclei and micronuclei occurring in healthy thymus tissue (top) and in thymic lymphoma (middle and bottom) from the indicated genotypes. Sections were stained with Hoechst (DNA, blue) and lamin A/C (green); yellow arrowheads indicate complete micronuclei through lamin A/C; red arrowheads show micronuclei with incomplete lamin A/C. (B) Plot showing the percentage of micronucleated cells experiencing micronuclear envelope disruption in healthy thymus, liver, and spleen tissues, as determined by incomplete lamin A/C signal co-occurring with micronuclear DNA. n = 3 tissue types per one biological replicate for each genotype (also see Table S1). (C) Plot showing percentage of micronuclei with nuclear envelopes lacking complete lamin A/C in thymic lymphoma tissues from the indicated genotypes. n = 3 biological replicates per genotype; P = 0.76, ns (also see Table S3). Data points indicate biological replicates, P values were calculated via unpaired Student’s t test.