coordination of cell polarity during xenopus gastrulation协调细胞极性在非洲爪蟾蜍原肠胚形成.pdfVIP

Coordination of Cell Polarity during Xenopus Gastrulation 1,2 1 1,2 Asako Shindo , Takamasa S. Yamamoto , Naoto Ueno * 1 Division for Morphogenesis, Department of Developmental Biology, National Institute for Basic Biology, Myodaiji, Okazaki, Aichi, Japan, 2 Department of Basic Biology, School of Life Science, The Graduate University of Advanced Studies (SOKENDAI), Myodaiji, Okazaki, Aichi, Japan Abstract Cell polarity is an essential feature of animal cells contributing to morphogenesis. During Xenopus gastrulation, it is known that chordamesoderm cells are polarized and intercalate each other allowing anterior-posterior elongation of the embryo proper by convergent extension (CE). Although it is well known that the cellular protrusions at both ends of polarized cells exert tractive force for intercalation and that PCP pathway is known to be essential for the cell polarity, little is known about what triggers the cell polarization and what the polarization causes to control intracellular events enabling the intercalation that leads to the CE. In our research, we used EB3 (end-binding 3), a member of +TIPs that bind to the plus end of microtubule (MT), to visualize the intracellular polarity of chordamesoderm cells during CE to investigate the trigger of the establishment of cell polarity. We found that EB3 movement is polarized in chordamesoderm cells and that the notochord- somite tissue boundary plays an essential role in generating the cell polarity. This polarity was generated before the change of cell morphology and the polarized movement of EB3 in chordamesoderm cells was also observed near the boundary ¨ between the chordamesoderm tissue and naıve