SEMINAR: MBF 602 student seminar speaker Lyza Johnston Friday 11/5 4:00p

["Sidney Hartley" <shartley@rsmas.miami.edu>]

Population genetic structure and demographic history of the corallivorous gastropod, Coralliophila abbreviata as inferred from mitochondrial DNA and microsatellite markers

 

Abstract Coralliophila abbreviata is an ecologically important gastropod found on reefs throughout the tropical Western Atlantic and the Caribbean.  These snails cause substantial and chronic mortality of the threatened acroporid corals, Acropora palmata and A. cervicornis, and may inhibit the persistence and recovery of vulnerable populations of these corals.  Understanding the structure and dynamics of C. abbreviata populations is thus important for local and regional management and conservation efforts. Here, I used a 366bp portion of the mitochondrial Cytochrome b gene along with five highly polymorphic microsatellite markers to assess the genetic structure, connectivity, and demographic history of C. abbreviata populations from three coral host taxa (A. palmata, Montastraea spp., and Mycetophyllia spp.) and five geographic locations spanning the species range (Florida Keys, Navassa Is., St. Vincent and the Grenadines, Curacao, and Panama).   The demographic history of C. abbreviata was assessed using the mismatch distribution of mtDNA sequences as well as the imbalance index and bottleneck tests for microsatellite data.  Both marker classes indicated high levels of genetic diversity within C. abbreviata and little to no genetic structure among C. abbreviata populations from different coral hosts or geographic locations.   The mismatch distribution and the imbalance index both suggest that the study population has undergone a large, post-Pleistocene, demographic expansion that was preceded by a reduction in size or bottleneck.  Modern day population connectivity and structure as inferred from molecular variation should, therefore, be interpreted cautiously, as populations may not be in mutation-drift equilibrium.

Lyza Johnston

 

B.S. University of Florida, 2001

Entered Ph.D. program, fall 2005

Co-advisors: Margaret Miller and Diego Lirman

 

 

Sidney L.S. Hartley

University of Miami RSMAS

Division of Marine Biology and Fisheries

S. Grosvenor 315

Miami Fl 33149

305-421-4176

305-421-4600-fax