Figure 1

Gene and protein expression of CG-1A and CG-8 correlates spatially and temporally with precartilage condensation pattern formation in vitro. (a) Relative expression of CG-1A measured by qRT-PCR at successive stages of development of leg-bud micromass cultures. (b) Relative expression of CG-8-specific mRNA measured in the same samples as (a). Differences between mRNA values at 24 h and dissociated but uncultured 5-day leg autopod precartilage cells (0 h calibrator samples) were statistically analyzed by Student's t-test. Results are shown as mean ± S.E.M. (* p < 0.05). (c, d) Gene expression of (c) CG-1A and (d) CG-8 in 2-day leg micromass cultures, assayed by in situ hybridization, is spatially coincident with condensations. Images are representative of two independent results. Inset in (c), condensation at same magnification from no-probe control culture. (e-h) Spatial localization of CG-1A protein in vitro by indirect immunostaining at (e) 15 h, (f, g) day 3 (low and high magnification, respectively) and day 6 (h). Inset in (e), region at same magnification from center of control culture in which no primary antibody was applied. Inset in (h), region at same magnification from 6 day culture stained for cartilage with Alcian blue. Images (c), (d) and (g) are at the same magnification; scale bar in (c) represents 0.2 mm. Images (e), (f) and (h) are at same magnification; scale bar in (e) represents 1 mm.