Linking integrin to IP 3 signaling is important for ovulation in Caenorhabditis elegans

Signals from germ and myoepithelial sheath cells initiate ovulation in Caenorhabditis elegans . The coordinated dilation and contraction of spermatheca lead to subsequent fertilization of oocyte. Either the dominant negative mutant pat‐3 β integrin or disruption of talin expression block ovulation [Cram, E.J., Clark, S.G. and Schwarzbauer, J.E. (2003) Talin loss‐of‐function uncovers roles in cell contractility and migration in C. elegans . J. Cell. Sci. 116, 3871–3878; Lee, M., Cram, E.J., Shen, B. and Schwarzbauer, J.E. (2001) Role of β pat‐3 integrins in development and function of Caenorhabditis elegans muscles and gonads. J. Biol. Chem. 276, 36404–36410], suggesting that the interaction between the cell and the extracellular matrix (ECM) is also important for ovulation. Here, we report that integrin plays an essential role in fertility via IP 3 signaling. Sterility caused by RNAi of pat‐3 and ECM molecules was suppressed by increased IP 3 signaling. Our data suggest that the cell–ECM interaction controls ovulation via IP 3 signaling.