Fig. 8. The effect of FGF2, other cytokines and Hox genes on cell differentiation of the cranial neural crest in vitro. A histogram summarizing the results of the experiments from Fig. 4 showing how Hox genes control cell differentiation of the cranial neural crest cells. For comparison, we included data on differentiation of anterior (somite level 10-12) and posterior (somite level 32-33) trunk neural crest cells. Both Hoxa2 and Hoxd10 can suppress chondrogenesis in cranial crest cells although to a different extent. Hoxa2 limits the rate of chondrogenesis by about 30%, whereas Hoxd10 completely suppresses it. Other cell types are also affected differently: Hoxa2 does not alter the overall rate production of smooth muscle or glial cells but Hoxd10 strongly limits myogenesis and gliagenesis relative to uninfected condition. The total number of cultures tested for each of the cell types is indicated above the representative bars. Note that all cultures were scored for melanogenesis.