Figure 3.En2 is expressed in mouse T-cell development. RT-PCR analysis of the indicated sorted stages of T-cell development shows that En2 is expressed in CD4⁺ CD8⁺ DP and CD8⁺ SP thymocytes, and in CD8⁺ T cells in the spleen. The identity of the En2 transcript was confirmed by using as positive controls cDNAs from mouse ES cells and from E16 mouse embryo head, and by using a sequenced En2 probe to hybridize a Southern blot of the amplified PCR products (lower lane).