Fig. 1.

YY1 is required for early T cell and double positive T cell development. (A-I) All Yy1^f/f Mx1-cre and Mx1-Cre mice were treated with four doses of pI-pC and evaluated 3-7 days after the last injection. (A) RT-qPCR to detect Yy1 transcript level. (B) Western blot and quantification to detect the YY1 deletion efficiency in total thymocytes. (C) Representative image of the thymus of Mx1-Cre and Yy1^f/fMx1-Cre mice and quantification of thymus weight and total numbers. (D) Representative flow gating strategy for DN1 (Lin⁻CD44⁺CD25⁻), c-Kit⁺ DN1 (Lin⁻c-Kit⁺CD44⁺CD25⁻), DN2 (Lin⁻CD44⁺CD25⁺), DN3 (Lin⁻CD44⁻CD25⁺) and DN4 (Lin⁻CD44⁻CD25⁻). Lineage markers include CD4, CD8, B220, Ter 119, Gr1, Mac1 and NK1.1. Lineage gating strategy was included in Fig. S1. (E) Quantification of percentage and absolute cell number of each DN population. (F) Representative flow gating strategy for double positive (DP) (CD4⁺CD8⁺), CD4⁺ T cells (CD4⁺CD8⁻) and CD8⁺ T cells (CD4⁻CD8⁺). (G) Quantification of percentage and absolute cell number of DP, CD4⁺ T cells and CD8⁺ T cells. (H) Representative flow gating strategy for CD127⁻ LMPP (Lin⁻Sca1^hic-Kit^hiCD135^hiCD127⁻), CD127⁺ LMPP (Lin⁻Sca1^hic-Kit^hiCD135^hiCD127⁺) and CLP (Lin⁻Sca1^loc-Kit^loCD135^hiCD127⁺) cells. (I) Quantification of percentage and absolute cell numbers of CD127⁻ LMPP, CD127⁺ LMPP and CLP populations. n represents the number of mice. Data are presented as mean± s.e.m. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001 (two-tailed unpaired Student's t-test).