Fig. 3.

Tissue-specific expression of the HOX genes. For HOX genes that did not show axial restriction by WISH or RNAseq in uninjured animals, all others were detected in specific tissues. Most often, brain and nerve cord expression was detected and confirmed by dFISH with the marker chat in green to mark cholinergic neurons (a–l). Post-2b showed detectable expression in stem cells using the marker piwi-1 (m, n), and Post-1 was found to be expressed in a small subset of piwi-1 ⁺ cells that are in the anatomical location of primordial germ cells in asexual planarians (o, p) [71, 72]. The remaining genes were found to be expressed in the epithelium (q, r), the body opening (s, t), the pharynx (u), as well as unknown mesenchymal cells with broad distribution (v, w). Scale bars = 50 μm