The indicated thymic progenitor population was sorted via FACS and then loaded into a Fluidigm C1 small cell capture chip for single-cell capture, lysis, reverse transcription, and preamplification. Preamplified products were analyzed on a BioMark HD with EvaGreen chemistry. The genes analyzed were selected based on bulk RNA sequencing data and/or prior publications, including genes relevant for gamma/delta T cells and T cell progenitors. B6=C57BL/6J, Rag=B6.Rag1-/-, Tcrd=B6.Tcrd-/-, DN1d=Live/TCRd-/Lin-/CD44+/CD25-/CD24+/cKit-, DN2=Live/TCRd-/Lin-/CD44+/CD25+/cKit+, cKit-=Live/TCRd-/Lin-/CD44+/CD25-/cKit-. Lin=CD3/CD8/CD11b/CD11c/CD19/Gr-1/NK1.1/TCRb/Ter-119 Sample naming nomenclature is as follows: MouseLine_CellPopoulation_DateCaptured_CaptureChamber_CellNumberInChamber Overall design: Single-cell qPCR analysis using the Fluidigm C1 platform. Cell capture, lysis, RT, and preamp is all automated to avoid the potential for operator-introduced inconsistencies. All preamplified products (~3.5 microliters) were diluted with an additional 5 microliters of C1 DNA Dilution Reagent prior to qPCR analysis.