Title       : Mitochondrial DNA as a Tool for Studying the Genetic
              Relationships of Marine Invertebrates with Planktonic
              Larvae:  Research Fellowship in Marine Biotechnology
Type        : Award
NSF Org     : OCE
Latest
Amendment
Date        : August 24,  1990
File        : a8915297

Award Number: 8915297
Award Instr.: Continuing Grant
Prgm Manager: Phillip R. Taylor
              OCE  DIVISION OF OCEAN SCIENCES
              GEO  DIRECTORATE FOR GEOSCIENCES
Start Date  : September 1,  1989
Expires     : August 31,  1992
Expected
Total Amt.  : $84,000
Investigator: Lani   West
              Dennis A Powers
Sponsor     : Stanford University
              Encina Hall
              Stanford, CA  94305                         415/723-2300

NSF Program : 1650     BIOLOGICAL OCEANOGRAPHY
Fld Science : 43       Biological Oceanography
Fld Applictn: 0204000  Oceanography
Abstract    :
          A fundamental problem in the study of marine ecology is to
     identify natural populations and understand how they change
     through time. This problem is especially challenging in marine
     organisms that metamorphose during development or change habitats
     throughout their life cycle. Adult stages of many species are
     benthic (e.g. barnacles), while their larval stages are
     planktonic and may disperse over long distances. Many aspects of
     the ecology of adult populations of coastal invertebrates have
     been intensively studied, but the effects of larval dispersal on
     genetic structure of populations are unclear and potentially
     extensive.
     The goal of this fellowship research is to gain knowledge of
     the degree to which dispersal and selection combine to affect
     variation between populations. Genetic differences may arise via
     natural selection, genetic drift, non-random mating, and
     mutation. Differentiation is reduced by gene-flow between
     populations: dispersal of propagules such as eggs, sperm, larvae,
     cysts, or adults. These two forces are usually in a state of flux
     and the genetic patterns we see at one point in time depend on
     the relative strengths of these forces.
     Dr. West will compare individual mitochondrial DNA sequences
     of planktonic barnacle larvae and newly settled juveniles
     collected adjacent to adult sites. Differences between these
     groups and possibly changes within cohorts through time will
     yield a new perspective on formation and maintenance of the
     genetic structure of these populations.  Mitochondrial DNA
     analysis can reveal the degree to which larvae travel as clouds
     of closely related individuals. Continued sampling of these
     patterns through time gives clues to the amount of genetic
     fluctuation that a population may naturally experience. The
     studies are made possible by means of primer-directed enzymatic
     DNA amplification using the polymerase chain reaction (PCR).