mta3 knockdown has no effect on hematopoietic cell apoptosis and proliferation. (A) gata1 expression was similarly affected by injection with 5 ng of tMO alone or in combination with 5 ng of p53 MO. It suggests that tMO-induced hematopoietic defects are not associated with off-target effect by MO-activated p53 signaling pathway. (B) Cell apoptosis was detected by TUNEL assay in 24 hpf embryos. The bottom panel showed an enlarged trunk region in which intermediate cell mass (ICM) resided. Injection with mta3 tMO or mRNA had no obvious effect on cell apoptosis within the ICM. (C) Cell proliferation was detected by whole-mount in situ immunohistochemistry using phospho-H3 antibody in 24 hpf embryos. The bottom panel showed ICM regions at higher magnification. Injection with mta3 tMO or mRNA had no obvious effect on cell proliferation within the ICM. All embryos were lateral views with anterior to the left.