Gα(13) is closely related to hematopoiesis in zebrafish

Heterotrimeric guanine nucleotide-binding regulatory proteins (G proteins) function as signal transducers and control many different physiologic processes. G proteins can be grouped into four families: G(s), G(i), G(q) and G(12). Gα(13) belongs to the G(12) family. In zebrafish, there are two isoforms of Gα(13): Gα(13)a and Gα(13)b. We show here that knockdown of Gα(13)b in zebrafish results in hematopoietic and angiogenic defects. The Gα(13)b morphants don't show complete loss of expression of gata1, pu.1 or flk until 35 hpf suggests that Gα(13)b is closely related to the development of hematopoietic cells. Further studies reveal that blood cells and vascular endothelial cells have undergone apoptosis through a p53-dependent pathway in Gα(13)b-depleted embryos. Injection of p53 morpholino could partially rescue the phenotype of Gα(13)b morphants. These data possibly demonstrate a new role for Gα(13) in cell survival.