Table 4.

Gli2^DR interferes with Gli1 and Gli3 activator functions^@

Morpholino	Number of islet-labeled cells in the hindbrain		Number of islet-labeled cells in ventral spinal cord#
	WT heterozygotes (gli2+/DR)*	yot mutant (gli2 DR/DR)*	WT heterozygotes (gli2+/DR)*	yot mutant (gli2 DR/DR)*
none§	223 ± 5 (4)	56.5 ± 4.4 (4)	34 ± 2.9 (4)	4.2 ± 1.4 (4)
gli1 MO£	93.8 ± 8.2 (4)	2.3 ± 2.1 (4)	25.9 ± 5.8 (4)	0.5 ± 0.1 (4)
	P < 0.001	P < 0.001	P < 0.01	P < 0.05
none§	304.8 ± 23.6 (5)	84.6 ± 22.9 (5)	33.6 ± 2.2 (5)	19.4 ± 0.7 (5)
gli3 MO†	233 ± 33.2 (5)	118.8 ± 32.1 (5)	16.4 ± 2.1 (5)	3.1 ± 1.7 (5)
	P < 0.01	P > 0.05 (NS)	P < 0.001	P < 0.001

^@While the numbers of control and MO-injected embryos were much higher (>40 for each treatment), we counted motor neuron cell bodies in 4–5 representative embryos for each condition. Embryos were genotyped by PCR.

^#Number of labeled cells per hemisegment.

^*Number of embryos scored in parenthesis.

^£Approximately 5 ng of gli1 morpholino (see Materials and methods) was injected per embryo. In our hands, this amount did not result in an observable loss of nk2.2 expression in wild-type embryos as described previously (Karlstrom et al., 2003), suggesting that it is a suboptimal dose. Injection of larger doses generated deformed embryos, and was not pursued further.

^§The numbers of hindbrain and spinal motor neurons in control wild-type and mutant embryos in the two experiments (performed about one year apart) are substantially different. We attribute these differences to variations in age of embryos, islet antibody staining intensity, and genetic background. Importantly however, the responses to gli1 and gli3 MO injections are very similar between the two experiments.

^†Approximately 30 ng of gli3 MO was injected per embryo. See Table 3 for details.