RUI: Mechanisms Underlying Limulus behavior: from Molecules to Movements

Plymouth State University, Plymouth NH

Investigators

Abstract

Internal biological clocks play important regulatory roles in virtually every living organism. The circadian clock in animals regulates daily activity rhythms and is composed of a molecular control system involving the protein PER. Recent preliminary evidence suggests that PER may also be an important part of the clock(s) controlling circatidal (~12.4 hour cycle) rhythms in the horseshoe crab, Limulus polyphemus. The first goal of the project is to use molecular techniques to investigate the molecular mechanisms that underlie both circadian and circatidal rhythms in Limulus and to localize the clocks that drive these rhythms to specific brain regions. A second goal will be to determine if circatidal rhythms are controlled by two 24 hr "circadian clocks" that each drive one of the high tide bouts of activity; an outstanding issue that has remained unanswered for decades. Third, for the first time in an aquatic invertebrate, the pattern of biological rhythms that are actually expressed by freely moving horseshoe crabs in their natural habitat will be recorded using a newly developed monitoring technique. The overall results will, for the first time in any species, localize a clock controlling circatidal behavior and will also identify the long sought after circadian clock in Limulus. Ultimately, the data obtained will allow for a full understanding of the mechanisms underlying the expression of rhythmic patterns of locomotion in this commercially and ecologically important species, from the molecular to the ecological level. This project will significantly enhance the training of undergraduates in the sciences at an institution that educates many of the K-12 educators in the state. Over half of the student researchers are likely to be women and some will be from under-represented minorities. In addition, many of the students will be first generation university students from lower economic sectors.