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...