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Abstracts of the summer presentations were first published in The Biological Bulletin in its October 1933 issue and, excepting the World War II period (1942–1945), the proceedings of the General Scientific Meetings have been so published for 55 years. In 1991, the editors of the Bulletin replaced the abstracts with peer-reviewed short reports, which are more substantial and more credible. This year’s meeting included 56 presentations, and 47 reports are published in this issue.
To encourage greater participation in the General Scientific Meetings, the MBL’s Science Council recently instituted the MBL Awards for the best paper presented at the GSMs by a senior investigator, a junior faculty member or postdoctoral fellow, a graduate student, and an undergraduate. The awards—based on both the presentation and the short report—are made by the Editor of The Biological Bulletin with recommendations from meeting organizers, session chairs, and participants. This year, the Editor also selected two student presentations for Honorable Mention.
The four presentations selected for MBL Awards this year reflect the broad scope of MBL science and the interconnectedness of comparative biology. We find, among these reports, a special feature of one animal used to analyze characteristics of organisms in another kingdom; the neural control of unique organs effecting camouflage and communication; a mode of neurogenesis described and then used as a phylogenetic character; and molecular assays as potential prognosticators of algal blooms. This year’s awardees are listed below together with the title of their presentation and a brief summary of each project. The page on which the full report begins is also indicated. —The Editor August 2002
Senior Award
Peter B. Armstrong (University of California, Davis) (with Margaret T. Armstong, R. L. Pardy, Alice Child, and Norman Wainwright) Immunohistochemical demonstration of lipopolysaccharide in the cell wall of a eukaryote, the green alga Chlorella (p. 203)
Lipopolysaccharides (LPS) are components of the outer cell membrane of gram-negative bacteria; they are supposedly restricted to prokaryotes but have recently been detected in Chlorella. A protein, Limulus anti-LPS factor (LALF), is secreted by horseshoe crab blood cells, binds to bacterial endotoxin and neutralizes it. An immunohistochemical test based on this reaction and on a tagged antiserum raised to LALF was used to localize an LPS-like molecule to the cell surface of Chlorella, a eukaryote. Thus, in addition to its presence in some prokaryotes, LPS appears also to be present at the cell surface of certain eukaryotes.
Junior Award
Michael Smotherman (University of California, Los Angeles) Acetylcholine mediates excitatory input to chromatophore motoneurons in the squid, Loligo pealeii (p. 231)
Thousands of chromatophores distributed throughout the skin of all decapod cephalopods function in camouflage and communication. The size (and thus visibility) of each of the pigment-filled chromatophoric sacs is controlled by a set of muscles, which are innervated from the central nervous system by motoneurons that project from the anterior and posterior chromatophore lobes (PCL). Acetylcholine (ACh) and nicotine applied directly to cell bodies in the PCL expanded a specific population of chromatophores on the surface of the ipsilateral mantle. Thus, the excitatory input to the chromatophoric motoneurons is, at least in part, cholinergic.
Graduate Student Award
Beate Mittmann (Humboldt-Universität, Berlin) Early neurogenesis in the horseshoe crab Limulus polyphemus and its implication for arthropod relationships (p. 221)
Within the neuroectoderm on the ventral surface of Limulus embryos, clusters of bottle-shaped cells invaginate dorsally, probably never divide again, and form the ventral ganglia. This mode of gangliogenesis in Limulus—the most primitive chelicerate extant—is similar to that in all of the terrestrial arachnids (e.g., spiders) that have been investigated to date. Thus it is likely to be the ancestral mode of ganglion formation in the chelicerates. In contrast, gangliogenesis in insects and crustaceans occurs through the formation of neuroblasts; so this process, distinct from that in chelicerates, is probably derived and can be seen as an apomorphic character for a monophyletic crustacean-insect unit.
Undergraduate Award
Jane La Du (Oregon State University) (with Deana Erdner, Sonya Dyhrman, and Don Anderson) Molecular approaches to understanding population dynamics of the toxic dinoflagellate Alexandrium fundyense (p. 244)
Some dinoflagellates in the genus Alexandrium produce neurotoxins; and when the algae bloom, these toxins accumulate sufficiently in shellfish that consumers are poisoned. To monitor the development of such a harmful algal bloom (HAB), predict its effects, and thus mount credible public warnings, a pair of assays for Alexandrium fundyense are being developed that would rapidly and reliably measure cell density and growth rate. These assays are based on two algal gene fragments. One encodes a part of ribulose-1,5-bisphosphate carboxylase, a Calvin-Benson enzyme; so its expression is a likely marker for growth rate. The second fragment—a candidate for quantifying cell density—is species specific and encodes for large subunit ribosomal RNA. Specific primers for both fragments have been designed and tested in quantitative PCR, and show promise for use in the field.
Student Honorable Mention
Jeremy M. Testa (SUNY, Syracuse) (with Matthew A. Charette, Edward R. Sholkovitz, Matt C. Allen, Adam Rago, and Craig W. Herbold) Dissolved iron cycling in the subterranean estuary of a coastal bay: Waquoit Bay, Massachusetts (p. 255) D. E. Arnolds (Williams College) (with S. J. Zottoli, C.E. Adams, S. M. Dineen, S. Fevrier, Y. Guo, and A. J. Pascal) Physiological effects of tricaine on the supramedullary/dorsal neurons of the cunner, Tautogolabrus adspersus (p. 188)
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