Fig. S1

spt and ntl translation-blocking morpholinos phenocopy the appropriate single and double mutant phenotypes. (A) Sequences of MOs used to deplete embryos of Spt/Ntl activity. The ntla MO was used in an earlier study (Nasevicius and Ekker, 2000). MOs were injected at a total concentration of 5 ng/nl. To deplete both factors, all four MOs were combined at a concentration of 1.25 ng/nl each and for each single depletion the two appropriate MOs were combined at a concentration of 2.5 ng/nl each. Each embryo was injected with a total of 15 ng to 25 ng of MO. (B-E) Live pictures of 24 hpf embryos following MO injection into one- to four-cell stage embryos. The spt single MO and spt;ntl double MO phenotypes are more necrotic than the corresponding genetic mutants at this stage (Amacher et al., 2002). (F-I) shh expression in the ventral midline is completely abolished posteriorly in 24 hpf embryos depleted of spt and ntl function, and single and double morphant phenotypes mimic those previously demonstrated for genetic mutants (Amacher et al., 2002). Expression of the krox20 hindbrain marker, which labels hindbrain rhombomeres 3 and 5, is included for reference and is not affected in any of the MO-injected embryos. (J-M) Muscle tropomyosin expression is completely abolished in 24 hpf embryos depleted of spt and ntl function, and both single and double morphant phenotypes mimic those previously demonstrated for genetic mutants (Amacher et al., 2002).