Jak2 Deficiency Defines an EssentialDevelopmental Checkpoint in DefinitiveHematopoiesis
نویسندگان
چکیده
Janus kinases (Jaks) play an important role in signal transduction via cytokine and growth factor receptors. A targeted inactivation of Jak2 was performed. Jak2-/- embryos are anemic and die around day 12.5 postcoitum. Primitive erythrocytes are found, but definitive erythropoiesis is absent. Compared to erythropoietin receptor-deficient mice, the phenotype of Jak2 deficiency is more severe. Fetal liver BFU-E and CFU-E colonies are completely absent. However, multilineage hematopoietic stem cells (CD34low, c-kit(pos)) can be found, and B lymphopoiesis appears intact. In contrast to IFNalpha stimulation, Jak2-/- cells do not respond to IFNgamma. Jak2-/- embryonic stem cells are competent for LIF signaling. The data provided demonstrate that Jak2 has pivotal functions for signal transduction of a set of cytokine receptors required in definitive erythropoiesis.
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عنوان ژورنال:
- Cell
دوره 93 شماره
صفحات -
تاریخ انتشار 1998