My research interests focus on Cell Biology and Physiology of fertilization and early embryonic development.

  • For the doctoral degree (University of California, Davis) I investigated the physiological and fine structural changes associated with egg activation in the decapod Sicyonia ingentis.
  • As an NIH Post-doctoral fellow (UC Davis School of Medicine) I studied the role of trypsin-like enzymes on steroidal induction human sperm activation.
  • As a post-doctoral fellow, and later on as a research faculty, at the UC Davis Bodega Marine Lab, I worked on many research projects, including:
    • Xenobiotic induction of stress protein expression in sea urchin embryos
    • Subcellular effects of lignin-derived macromolecules on echinoderm fertilization
    • Cytoskeletal dynamics during early algal development and the effects of environmental pollutants on it
    • Physiology of herring sperm activation
    • Effect of polycyclic aromatic hydrocarbons (PAH) on sea urchin embryonic axis specification


Research in my laboratory at Sonoma State University focuses on the developmental effects of PAHs on invertebrate (sea urchins) and vertebrate (zebrafish) early embryos. These compounds are a class of organic xenobiotics and are released into the environment from a variety of natural and anthropogenic sources. Several studies have demonstrated that PAHs significantly contribute to human and other animal health risk through their carcinogenic, genotoxic and teratogenic effects.

The toxicological effect of PAHs is typically mediated through PAH binding to the aryl hydrocarbon receptors (AhR) in target cells, and subsequent altered gene expression. However, our recent studies using sea urchin embryos have demonstrated a direct link between PAH exposure and accumulation of nuclear β-catenin (a highly conserved multifunctional protein that regulates cell-cell adhesion and gene transcription) in embryonic cells and abnormal axis specification during development.


Nuclear β-catenin accumulation is an evolutionarily conserved part of the canonical Wnt/wingless signaling pathway involved in both regulation of cell proliferation and axis determination during metazoan embryogenesis. In sea urchins embryos, we have shown that PAHs down-regulate the activity of a crucial component in the Wnt pathway, Glycogen Synthase Kinase (GSK)-3β, and thus its ability to regulate cytosolic stability of β-catenin causing its increased nuclear accumulation. Using early embryos of the sea urchins (Strongylocentrotus purpuratus and Lytechinus anamasus) as experimental systems, we currently seek to:

  • establish and further document the relationship between PAH exposure, nuclear β-catenin accumulation, and abnormal embryonic axis specification, and
  • determine the effects of PAHs on the activity of GSK-3β, its phosphorylation states, as well as its ability to regulate cytosolic stability of β-catenin.

In addition, zebrafish (Danio rerio) early embryos are currently being used to investigate how PAHs may interfere with normal embryogenesis, specifically the effects of PAHs on:

  • muscle cell proliferation
  • somite development and differentiation, and
  • skeletogenesis.

Interested undergraduates and prospective graduate students may contact me at for more information about these research projects.



  • Pillai, M.C., Vines, C.A. and Cherr, G.N. 2010. Developmental effects of polycyclic aromatic hydrocarbons: disruption of embryonic axis development in sea urchins through a β-catenin dependent pathway. Biotechnological Solutions to Environmental Sustainability, Vellore Institute of Technology Press, India.

  • Cherr, G.N., M. Morisawa, C.A. Vines, Yoshida, K., Smith, E.H., Matsubara, T., Pillai, M.C., Griffin, F.J. and Yanagimachi, R. 2008. Two egg derived molecules in sperm motility initiation in the Pacific herring (Clupea pallasi). Int. J. Dev. Biol., 52: 743-752.

  • Pillai, M.C., Vines, C.A., Wikramanayake, A.H. and Cherr, G.N. 2003. Polycyclic aromatic hydrocarbons disrupt axial development in sea urchin embryos through a beta-catenin dependent pathway. Toxicology, 186: 93-108.

  • Vines, C.A., Kiroku, K., Griffin, F.J., Pillai, M.C., Morisawa, M., Yanagimachi, R. and Cherr, G.N. 2002. Motility initiation in herring sperm is regulated by a reverse sodium- calcium exchange. Proc. Natl. Acad. Sci. (USA). 99: 2026-2031.

  • Griffin, F.J., Pillai, M.C., Vines, C.A., Hibbard-Robbins, T., Yanagimachi, R. and Cherr, G.N.1998. Effect of salinity on fertilization and development in herring. Biological Bulletin, 194: 25-35

  • Shamseldin, A., Clegg, J.S., Friedman, C.S., Cherr, G.N. and Pillai M.C. 1997. Induced thermotolerance in the Pacific oyster, Crassostra gigas. J. Shell Fish Res., 16: 487-49. Pillai, M.C., Blethrow, H.S., Higashi, R.M. and Cherr, G.N. 1997. Inhibition of the sea urchin sperm acrosome reaction by a lignin-derived macromolecule. Aquat. Toxicol. 37: 139-156.

  • Vines, C.A., Griffin, F.J., Pillai, M.C., Yanagimachi, R., Hibbard-Robbins, T., and Cherr, G.N. 1996. A specialized role for the Pacific herring egg chorion in sperm motility initiation. In The Fish Egg: Its Biology and Culture Symposium Proceedings (D. MacKinlay and M. Eldridge, eds.), International Congress on the Biology of Fishes, San Francisco State University, pp. 167-172.

  • Griffin, F.J., Vines, C.A., Pillai, M.C., Yanagimachi, R. and Cherr, G.N. 1996. The sperm motility initiation factor (SMIF) of the Pacific herring egg chorion: A minor component of major function. Develop Growth &Differ., 38: 193-202.

  • Cherr, G.N. and Pillai, M.C. 1995. Environmental Factors affecting reproduction and development of Pacific herring in the San Francisco Estuary. California Dept. of Fish and Game Publication, pp. 8-9.

  • Garman, G.D., Pillai, M.C., and Cherr, G.N. 1994. Nuclear events during early development in gametophytes of Macrocystis pyrifera, and the temporal effects of a marine contaminant. Marine Biology, 121: 355-363.

  • Garman, G.D., Pillai, M.C., and Cherr, G.N. 1994. Inhibition of cellular events during algal gametophyte development: Effects of select metals and an aqueous petroleum waste. Aquatic Toxicology. 28: 127-144.

  • Pillai, M.C., R. Yanagimaci and Cherr, G.N. 1994. In Vivo and in vitro initiation of sperm motility using fresh and cryopreserved gametes from the Pacific herring, Clupea pallasi. Journal of Experimental Zoology. 214: 521-527.

  • Cherr, G.N., Fan,T.W-M., Pillai, M.C., Shields, T. S., and Higashi, R.M. 1993. Electrophoretic separation, characterization, and quantification of biologically active lignin-derived macromolecules. Analytical Biochemistry. 214: 521-527.

  • Pillai, M.C., Shields, T.S., Yanagimachi, R. and Cherr, G.N. 1992. Isolation and partial characterization of the sperm motility initiating factor from eggs of the Pacific Herring, Clupea pallasii. Journal of Experimental Zoology, 265: 336-342.

  • Fan, T.W.-M., Higashi, R.M., Cherr, G.N. and Pillai, M.C. 1992. Produced water perturbs reproduction in mussels as monitored in vivo by NMR spectroscopy and imaging. In: Environmental Science Research (J.P. Ray and F.R. Engelhardt, eds.), 46: 403-414.

  • Yanagimachi, R., Cherr, G.N., Pillai, M.C. and Baldwin, J.D. 1992. Factors controlling sperm entry into the micropyles of salmonid and herring eggs. Development, Growth and Differentiation, 34: 447-461.

  • Baldwin, J.D., Pillai M.C. and Cherr, G.N. 1992. The response of sea urchin embryos to aqueous petroleum wastes includes the expression of a high molecular weight glycoprotein. Marine Biology, 114: 21-30.

  • Pillai, M.C. , Baldwin, J.D. and Cherr, G.N. 1992. Early development in an algal gametophyte: role of cytoskeleton in germination and nuclear translocation. Protoplasma, 170: 34-45.

  • Clark, W.H., Jr., Chen, T.-I., Pillai, M.C., Uhlinger, K., Shoffner-McGee J. and Griffin, F.J. 1991.The biology of gamete activation and fertilization in Sicyonia ingentis (Penaeoidea): present knowledge and future directions. Bull. Inst. Academia Sinica, Monograph, 16: 553-571.

  • Clark, W.H. Jr. and Pillai, M.C. 1991. Egg production, release and activation in the marine shrimp, Sicyonia ingentis. In: Crustacean Issues. Vol. 7, (A.M. Wenner and A. Kuris, eds.). Balkema Press, Rotterdam, pp. 3-8.

  • Lynn, J.W., Pillai, M.C., Glas, P. and Green, J.D. 1991. Comparative morphology and physiology of egg activation in selected Penaeoidea. In: Frontiers in Shrimp Research. (P. DeLoach, M.A. Davidson, W.J. Dougherty, eds.). Elsevier Science Publishers, Amsterdam, pp. 47-63.

  • Pillai, M.C. and Meizel, S. 1991. Trypsin inhibitors prevent the progesterone-initiated increase in intracellular calcium required for the human sperm acrosome reaction. Journal of Experimental Zoology, 258: 384-393.

  • Pillai, M.C., Griffin, F.J. and W.H. Clark, Jr. 1990. Post-spawning alterations of the extracellular matrices in the eggs of Sicyonia ingentis. (M. Hoshi and O. Yamashita, eds.). Advances in Invertebrate Reproduction, 5: 201-207.

  • Meizel, S., Pillai, M.C., Diaz-Perez, E. and Thomas, P. 1990. Initiation of the human sperm acrosome reaction by components of human follicular fluid and cumulus secretions including steroids. In: Fertilization in Mammals. (B.D. Bavister, J. Cummins, E.R.D. Roldan, eds.). Serono Symposia USA, Norwell, Massachusetts, pp. 205-222.

  • Clark, W.H., Jr., Yudin, A.I., Lynn, J.W., Griffin, F.J. and Pillai, M.C. 1990. Jelly layer formation in the penaeoidean shrimp eggs. Biological Bulletin, 178: 295-299.

  • Pillai, M.C. and Clark, W.H., Jr. 1990. Development of cortical vesicles in Sicyonia ingentis ova: Their heterogeneity and role in elaboration of the hatching envelope. Molecular Reproduction and Development, 26: 78-89.

  • Pillai, M.C. and Clark, W.H., Jr. 1988. Hatching envelope formation in shrimp (Sicyonia ingentis) ova: origin and sequential exocytosis of cortical vesicles. Tissue & Cell 20: 941-952.

  • Pillai, M.C., Griffin, F.J. and Clark, W.H., Jr. 1988. Induced spawning in the marine shrimp, Sicyonia ingentis. Biological Bulletin, 174:181-185.

  • Pillai, M.C. and Clark, W.H., Jr. 1987. Oocyte activation in the Marine shrimp, Sicyonia ingentis. Journal of Experimental Zoology, 244: 325-330.