Effect of mta3 overexpression on primitive erythropoiesis. (A) The expression of gata1 and hbbe3 at the 10-somite stage was increased when 350 pg of mta3 mRNA was injected. Embryos were in posterodorsal view with anterior to the top. (B-C) Overexpression of mta3 mRNA partially rescued gata1 and hbbe3 expression in mta3 tMO-injected embryos at the 10-somite stage (B) or gata1 expression at 24 hpf (C). (D) The expression of gata1 was reduced in 10 ng of mta3 sMO-injected embryos at the 10-somite stage and at 24 hpf, and this effect was efficiently rescued by coinjection of 350 pg of mta3 mRNA.