Apoptosis in LN-ras2 reconstituted mice. (A) LK3 thymocytes demonstrate normal morphology. (B) Nr9 thymocytes have condensed and fragmented nuclei (arrows). (C) LK2 TUNEL-stained thymus section. Small numbers of apoptotic cells (stained red) dispersed throughout the cortex are shown. (D) Nr9 TUNEL-stained thymus section. An elevation of apoptotic cells is shown. (E) LK3 TUNEL-stained spleen section. Small numbers of apoptotic cells are dispersed throughout the spleen. (F) Nr9 TUNEL-stained spleen section. Apoptotic cells clustered within lymphoid follicles are shown. (G) Spleen section from Nr9 showing morphology of apoptotic cells. (H) Nr16 TUNEL-stained section of intestinal node. Cytospun preparations (A and B) were stained with May-Grunwald and Giemsa (original magnification ×1,250). Tissue section (G) was stained with hematoxylin and eosin (original magnification ×1,250). TUNEL-stained tissue sections (C through F and H) apoptotic cells are stained red (original magnification ×125).