The FACS plot on the left is gated on Lin cells, and the plot on the right is gated on LSK cells (as shown in the plot on the left). LSK subpopulations were sorted from the indicated regions. Percentages are indicated. (B) 100 cells of the indicated precursors were sorted onto OP9-DL1 stroma, cultured for 9 d, and analyzed by FACS. The levels of CCR9-EGFP and CD44 expression are indicative of the maturity of each precursor, as T lineage–biased precursors are expected to progress faster, whereas precursors without a T lineage bias or those biased toward a non-T fate will take longer to develop to DN3 thymocytes. The histogram plots are gated on DN2/3 thymocytes in which CCR9-EGFP expression increases with the progression from DN2 to DN3 thymocytes (reference ). The results of three independent wells are shown in each histogram plot. Contour plots are gated on Lin CD90 cells, and the numbers in each quadrant indicate the mean frequency of each population from three independent experiments. (C) The results of a representative clonogenic myeloid progenitor assay are shown for a 96-well plate seeded with 5, 10, 20, or 40 cells of the indicated precursors. The number of detectable myeloid colonies for each well is given. (D) Semiquantitative RT-PCR was performed on fivefold dilutions of cDNA prepared from the indicated precursors with primers specific for the indicated transcripts. Primers specific for hypoxanthin-phosphoribosyl-transferase (HPRT) transcript were used as a loading control. PCR fragment sizes in base pairs are given in parenthesis.<p><b>Copyright information:</b></p><p>Taken from "The stream of precursors that colonizes the thymus proceeds selectively through the early T lineage precursor stage of T cell development"</p><p></p><p>The Journal of Experimental Medicine 2008;205(5):1187-1199.</p><p>Published online 12 May 2008</p><p>PMCID:PMC2373849.</p><p></p