Fig. 2.

PreMel and HEM share a common gene transcription pattern. a Phase-contrast images show ADSC fibroblastoid morphology in control conditions. b After 1 week of differentiation, long and thin cellular extensions are observed. c Along with these cellular protrusions, the entire cells look thinner with respect to a. This phenotype continues after the third (d) and fourth (e) week and resembles the phenotype of HEM (f). Black arrows highlight the long cellular protrusions. Scale bar = 250 μm. g Scheme of different stages and gene expression of HEM during mammalian differentiation. Some of these genes were evaluated during ADSC differentiation protocol. h PAX3 shows a constant increment during the protocol with a significant increase after 3 and 4 weeks. The same pattern is seen with i MITF-A and j MITF-M. k MC1R transcript increases significantly from the second week. l MLANA appears mostly during the second part of the protocol. m TRP2 expression is detected after 3 weeks of differentiation. n = 3, *P < 0.05 one-way ANOVA; statistical analysis was calculated with respect to the first week of differentiation. Non-differentiated ADSC were used as a control