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Updated: Jun 12, 2026

Preparation of Single-Cell Suspension of Mouse Thymic Epithelial Cells and Staining of Intracellular Molecules for Flow Cytometric Analysis
Published on: July 26, 2024
The endocytic adaptor Numb regulates thymus size by modulating pre-TCR signaling during asymmetric division
Rocio Aguado1, Nadia Martin-Blanco, Michael Caraballo
1Instituto de Parasitología y Biomedicina López-Neyra, CSIC, Parque Tecnológico Ciencias de Salud, Granada, Spain.
Abstract:
Stem cells must proliferate and differentiate to generate the lineages that shape mature organs; understanding these 2 processes and their interaction is one of the central themes in current biomedicine. An intriguing aspect is asymmetric division, by which 2 daughter cells with different fates are generated. Several cell fate determinants participate in asymmetric division, with the endocytic adaptor Numb as the best-known example. Here, we have explored the role of asymmetric division in thymocyte development, visualizing the differential segregation of Numb and pre-TCR in thymic precursors. Analysis of mice where Numb had been inhibited by expressing a dominant negative revealed enhanced pre-T-cell receptor (TCR) signaling and a smaller thymus. Conversely, Numb overexpression resulted in loss of asymmetric division and a larger thymus. The conclusion is that Numb determines the levels of pre-TCR signaling in dividing thymocytes and, ultimately, the size of the pool from which mature T lymphocytes are selected.
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