Long-term 2G exposure causes a reduction in cell number of mTECs.

(A) Flow cytometric analysis of thymic epithelial cells (TECs) in mice exposed to 2G for 14 days. Mice were exposed to 2 g gravity (2G) for 14 days or left under 1G (control). Vestibular apparatus are surgically disrupted in some mice (VL). TECs (CD45^–TER119^– EpCAM⁺) in total thymic cells were analyzed by staining with UEA-1-lectin, an mTEC marker, and CD80 antibody. Numbers in panels indicates percentage of each fraction. The percentages of UEA-1^– CD80^lo (containing cTECs), UEA-1⁺CD80^high (mTEC^hi), and UEA-1⁺CD80^low (mTEC^lo) cells among thymic stroma cells are summarized in right figures. “C” in graphs indicates 1G control. N = 6 each C, C with VL, and 2G with VL groups. N = 5 for 2G. NS indicates that the difference is not significant (Student’s t-test). NS indicates that the difference is not significant (Student’s t-test). (B) Cell numbers of total TECs (CD45^–TER119^– EpCAM⁺), UEA-1^– CD80^lo TECs (containing cTECs), mTECs (UEA-1⁺), mTEC^hi (UEA-1⁺CD80^high), and mTEC^lo (UEA-1⁺CD80^low) in the thymus are summarized in figures. N = 6 each C, C with VL, and 2G with VL groups. N = 5 for 2G. The asterisks indicate statistical significance at *P < 0.05 (Student’s t-test). NS indicates that the difference is not significant (Student’s t-test).