Gata2a and Gata3 are required for expression of sox1a and sox1b in V2 interneurons. (A-E′) Embryos injected with mismatch morpholinos (control, A-E) or with a mixture of morpholinos directed against gata2a and gata3 mRNA (A′-E′). Cells in the V2 domain are indicated by asterisks, KA′ cells by arrowheads and KA″ cells by arrows. (A-A″) Loss of function of Gata2a and Gata3 resulted in a reduction of tal2-expressing KA″ cells, an elimination of KA′ and decrease of tal2+ V2b cells. (B-B″) Reduction of gad67-expressing V2b and KA″ cells was noted in morpholino-injected embryos, whereas loss of function of Gata2a and Gata3 almost abolished gad67+ KA′ cells. (C-C″) Knockdown of Gata2a and Gata3 decreased sox1a+ V2 cells by 25% (n=650 cells) and almost abolished sox1a-expressing KA′. (D-D″) Loss of function of Gata2a and Gata3 decreased sox1b+ V2 cells by 35% (n=2016 cells) and almost eliminated sox1b-expressing KA′. (E-E″) V2a cells (vsx2+) were not affected in knockdown embryos. Data are mean±s.e.m. from 22 to 42 embryos from at least two independent experiments. Cells were counted from the yolk extension to the tail on both sides of the spinal cord. Statistical significance was assessed using the unpaired two-tailed Student's t-test. ***P≤0.001. Scale bar: 25 µm.
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