Generation of cell shape
Cell polarization, or the asymmetric placement of molecules within a cell, underlies many biological processes. Polarization can guide changes in cell shape, as in the development of neurons or during pollen tube growth. In plant and animal embryos, the basic organization of tissues often begins with polarization of the egg or zygote. We are investigating this process in zygotes of the fucoid brown algae (genera Fucus and Silvetia). These zygotes begin as radially symmetric cells, but within the first 10-12 hours polarization leads to local growth from one hemisphere generating a pear-shaped cell, and guides morphogenesis of the multicellular adult. Developmental polarity is first established by the position of fertilization, and can be reoriented by environmental signals such as the direction of sunlight. A dynamic actin cytoskeleton is required for both fertilization-induced polarization and light-induced reorientation of polarity.
Current research questions include:
1) Which protein pathways regulate the assembly of actin filaments in response to polarizing cues?
2) How do cells respond to more than one environmental cue, particularly if they are conflicting?
3) How do environmental toxins affect polarity establishment and development?
Artificial maturation of the American eel
In a collaboration with Dr. Ken Oliveira, we are investigating gametogenesis and fertilization in the American eel, Anguilla rostrata. After spending many years in or near freshwater habitats, adults migrate to and spawn in the Sargasso Sea, where investigations of reproductive behavior and early development are not possible. We have developed protocols to induce sexual maturation of both male and female eels, and our research has resulted in the first successful artificial fertilization in this species.
Current research questions include:
1) What are the stages and timing of early embryogenesis?
2) What are the effects of pollutants on gametogenesis and fertilization?
Cell polarization, or the asymmetric placement of molecules within a cell, underlies many biological processes. Polarization can guide changes in cell shape, as in the development of neurons or during pollen tube growth. In plant and animal embryos, the basic organization of tissues often begins with polarization of the egg or zygote. We are investigating this process in zygotes of the fucoid brown algae (genera Fucus and Silvetia). These zygotes begin as radially symmetric cells, but within the first 10-12 hours polarization leads to local growth from one hemisphere generating a pear-shaped cell, and guides morphogenesis of the multicellular adult. Developmental polarity is first established by the position of fertilization, and can be reoriented by environmental signals such as the direction of sunlight. A dynamic actin cytoskeleton is required for both fertilization-induced polarization and light-induced reorientation of polarity.
Current research questions include:
1) Which protein pathways regulate the assembly of actin filaments in response to polarizing cues?
2) How do cells respond to more than one environmental cue, particularly if they are conflicting?
3) How do environmental toxins affect polarity establishment and development?
Artificial maturation of the American eel
In a collaboration with Dr. Ken Oliveira, we are investigating gametogenesis and fertilization in the American eel, Anguilla rostrata. After spending many years in or near freshwater habitats, adults migrate to and spawn in the Sargasso Sea, where investigations of reproductive behavior and early development are not possible. We have developed protocols to induce sexual maturation of both male and female eels, and our research has resulted in the first successful artificial fertilization in this species.
Current research questions include:
1) What are the stages and timing of early embryogenesis?
2) What are the effects of pollutants on gametogenesis and fertilization?