FIGURE 5.

Meflin⁺ cells differentiate into multilineage cells in the adult period. (A) The experimental design for lineage tracing of Meflin⁺ cells into adulthood. Meflin‐CreERT2; LSL‐tdTomato mice were intraperitoneally administered 3 mg TAM 3 times every other day (eod) at the age of 8 weeks. Tissues were harvested at 9, 12 and 40 weeks of age. (B) Lineage tracing of Meflin⁺ cells labeled with tdTomato in brown (a–c) and white (d–f) adipose tissues, bone (g–i) and skeletal muscle (j–l) in the adult period. tdTomato⁺ cells appear to be fibroblastoid cells in the adipose tissues and skeletal muscle, immature chondroblasts in the bone, and perisinusoidal stromal cells in the BM one week after TAM administration (a, d, g, j). Those cells gave rise to mature brown adipocytes (c), mature chondrocytes (h), osteocytes (i) and skeletal myocytes (l). Some Meflin lineage cells retained their fibroblastoid morphology even 12 weeks and 8 months after TAM administration (b, e, f, i, k). Scale bars, 200 µm