Changing patterns of morphological structure, appearance of new macromolecular entities and patterns of localization of macromolecules are hallmarks of the developmental process. In my lab, the expression pattern, structure and function of storage proteins during animal development is a major focus. The abundance and large size of storage proteins make them attractive models for studying cellular localization phenomena. Many storage proteins are synthesized in one tissue, secreted into circulation and subsequently taken up by another tissue for utilization. This provides abundant questions of cellular and subcellular mechanisms of spacial and temporal patterns. Several of these proteins have homologues throughout the animal kingdom and the evolution of their structure and regulation interests us. The massive amount of storage proteins that are produced suggests that they are limiting factors in the survival of animals. We have begun a study of natural variation in amounts of stored proteins in eggs and serum of economically important animals. One species, the American lobster, Homarus americanus (Decapoda), is under substantial commercial harvest pressure. Understanding of the events leading up to ovulation and molting may help the lobster fishermen to leave more non-commercial lobsters at sea. In winter flounder, Pleuronectes americanus, embryonic utilization of egg proteins may provide a means to monitor normal and abnormal development during early embryogenesis in this bottom feeding organism which lives in the estuaries adjacent to sources of pollution. In Atlantic cod, Gadus morhua, measuring the serum titer of Vitellogenin may aid in monitoring the sexual maturation of cod populations. We also explore the cellular basis of pattern formation in oocytes of the cockroaches Blattella germanica and Periplaneta americana and the amphibian, Xenopus laevis with our studies of ion flux during early development. Our Ion Probe Facility is also being used to explore ionic factors surrounding the rapid growth of pollen tubes and root hair growth in conjunction with the Peter Hepler Lab which is a major force in this field of research.
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Growing Pollen Tubes Possess a Constitutive Alkaline Band in the Clear Zone and a Growth-dependent Acidic Tip (with J, A. Feijo; J. Sainhas; G. R. Hackett; and P. K. Hepler), Journal of Cell Biology (1999)
Using both the proton selective vibrating electrode to probe the extracellular currents and ratiometric wide-field...