Figure 1
Expression patterns of Gli3 and Alx4 in limb buds of emu, chicken and zebra finch embryos. The distal domain of Gli3 expression is posteriorly extended in limb buds of emu, chicken and zebra finch (a, n = 5; d, n = 9; g, n = 8), although it is most extensively expressed in the emu forelimb buds. Alx4 show a similar anterior expression in limb buds of all species (b, j, n = 5; e, l, n = 17; h, n, n = 3) at stage 25. Additional posterior expression of Alx4 is detected in both fore- and hindlimb buds of emu, chicken and zebra finch embryos at stage 26 (c, k, n = 6; f, m, n = 13; i, o, n = 7). The shapes of the limb bud are similar, but not exactly identical among species at the same stage14,22,23. c, d, j, k, Left limb buds flipped horizontally.
