Fig. 1. Spleen cellularity and composition of spleens in control and mutant mice. (A) Spleens of control, Pax8^-/- and Pax8^-/- TH-treated mice. (B,C) Spleen cellularity in controls and Pax8^-/- mice, treated or not with TH, and in controls, TR^0/0 and TRß^-/- mice. Nucleated splenocytes from 15-day-old mice were counted and cell numbers plotted as a cellularity index expressed as 10⁵ cells/g of body weight. [^*, P<0.005 compared with control; ^**, P<0.005 compared with Pax8^-/-, n=20 for control, n=20 for Pax8^-/-, n=4 for Pax8^-/- after 3 and 24 hours, n=10 for Pax8^-/- after 48 hours, n=13 for TR^0/0 and n=5 for TR^-/-]. (D) Analysis of spleen populations in wild-type, Pax8^-/- ß and TH-treated Pax8^-/- mice. Splenocytes were analyzed by flow cytometry using anti-B220 and anti-TER119 antibodies to identify cells belonging to the B and erythrocytic compartments, respectively. Numbers in the FACS profiles indicate percentages of the respective populations. (E) Total number of TER119- and B220-positive spleen subpopulations in wild-type, Pax8^-/- and TH-treated Pax8^-/- mice, plotted as a cellularity index (^**, P<0.002; ^*, P=0.05 compared with control; n=7 for control, n=9 for Pax8^-/- and n=5 for Pax8^-/- + TH). (F) Comparison of numbers of TER119-positive spleen subpopulations between 15-day-old and 21-day-old wild-type and TR^0/0 mice (^*, P=0.05 compared with control; n=3).