During mouse development, mesodermal cells generated via gastrulation play important roles in the morphogenesis of several tissues and organs. We focus on two types of mesodermal cells; one is precursor cells of the cardiovascular system in the lateral plate mesoderm, the other is precursor cells of somites that give rise to the axial structures such as vertebrae and skeletal muscles, in the paraxial mesoderm. We generate several knockout and knockin mice to understand the molecular mechanism of vasculogenesis, cardiogenesis and somitogenesis. In addition, we are interested in the mechanism of germ cell development. We found that mouse Nanos proteins, Nanos2 and Nanos3 are essential for germ cell development. Recent study reveals that Nanos2 is involved in the male germ cell fate specification. Since most of studies are conducted using in vivo systems established by gene-engineering technologies, we are interested in the development and application of new transgenic methods to improve the quality of the analyses.

Suzuki, A. and Saga, Y. (2008). Nanos2 suppresses meiosis and promotes male germ cell differentiation. Genes & Develop. 22, 430-435.

Oginuma M, Niwa Y, Chapman DL, Saga Y. (2008) Mesp2 and Tbx6 cooperatively create periodic patterns coupled with the clock machinery during mouse somitogenesis. Development 135, 2555-2562.

Kokubo H, Miyagawa-Tomita S, Saga Y.(2007). Hesr1/Hey1 and Hesr2/Hey2 regulate atrial-ventricular boundary formation in the developing heart through the repression of Tbx2. Development 134, 747-755.

Suzuki A, Tsuda M, and Saga Y. (2007). Functional redundancy among Nanos proteins and a distinct role of Nanos2 during male germ cell development. Development 134, 77-83.

Yasuhiko, Y., Haraguchi, S., Kitajima, S., Takahashi, Y., Kanno, J and Saga, Y. (2006). Tbx6-mediated Notch signaling controls somite-specific Mesp2 expression. Proc. Natl. Acad. Sci. USA, 103, 3651-3656.

Morimoto, M., Takahashi, Y., Endo, M.. Saga, Y. (2005). The transcription factor Mesp2 establishes segmental borders by suppressing Notch activity. Nature 435, 354-359