Kzp Regulates the Transcription of gata2 and pu.1 during Primitive Hematopoiesis in Zebrafish Embryos

Kaiso zinc finger-containing protein (Kzp), a maternally-derived transcription factor, controls dorsoventral patterning during zebrafish gastrulation. Here, we uncovered a new function for Kzp in zebrafish embryonic primitive hematopoiesis. The depletion of kzp led to defects in primitive hematopoiesis including the development of the erythroid and myeloid lineages. On the other hand, overexpression of kzp caused the ectopic expression of gata1, gata2, and pu.1. Chromosome immunoprecipitation assays revealed that Kzp protein directly binds to gata1, gata2, and pu.1 promoters. Interestingly, the ectopic expression of gata2 was able to rescue the erythroid, but not the myeloid lineage in kzp-depleted zebrafish embryos. gata1 expression controlled by Kzp was dependent on gata2 during primitive erythropoiesis. Our results indicate that Kzp is a critical transcriptional factor for the expression of gata2 and pu.1 to modulate primitive hematopoiesis.