Biological Invasions

, Volume 15, Issue 1, pp 225–241

Long-term population genetic structure of an invasive urochordate: the ascidian Botryllus schlosseri

  • Eitan Reem
  • Jacob Douek
  • Gadi Katzir
  • Baruch Rinkevich
Original Paper

DOI: 10.1007/s10530-012-0281-2

Cite this article as:
Reem, E., Douek, J., Katzir, G. et al. Biol Invasions (2013) 15: 225. doi:10.1007/s10530-012-0281-2

Abstract

The accelerated pace of marine biological invasions raises questions pertaining to genetic traits and dynamics underlying the successful establishment of invasive species. Current research stresses the importance of multiple introductions and prolonged gene flow as the main sources for genetic diversity, which, along with genetic drift, affect invasive species success. We here attempt to determine the relative contribution of gene flow and mutation rates as sources of genetic variability using the invasive tunicate Botryllus schlosseri as a model. The study was performed over a 13-year period in the Santa Cruz Harbor, California. With a characteristic life history of five generations/year, the Santa Cruz Botryllus population has already experienced approximately 155 generations since the onset of its invasion. The results (278 specimens, 127 scored alleles, five microsatellite loci) support limited gene flow rate (2.89 × 10−3) and relative genetic isolation. Furthermore, the study population was found to be influenced by both, genetic drift and a high mutation rate (2.47 × 10−2). These findings were supported by high fluctuations in the frequencies of microsatellite alleles, the appearance of new alleles and the loss of others. The balance between genetic drift and a high mutation rate is further elucidated by the high, stable level of genetic variation. We suggest that rapid mutation rates at the microsatellite loci reflect genome-wide phenomena, helping to maintain high genetic variability in relatively isolated populations. The potential adaptability to new environments is discussed.

Keywords

Genetic diversity Genetic drift Invasions Microsatellites Mutations 

Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Eitan Reem
    • 1
    • 2
  • Jacob Douek
    • 1
  • Gadi Katzir
    • 2
    • 3
  • Baruch Rinkevich
    • 1
  1. 1.Israel Oceanography and Limnological Research, National Institute of OceanographyHaifaIsrael
  2. 2.Department of Evolutionary and Environmental Biology, Faculty of Science and Science EducationUniversity of HaifaHaifaIsrael
  3. 3.School of Marine SciencesUniversity of HaifaHaifaIsrael
  4. 4.Department of Neurobiology and Ethology, Faculty of ScienceUniversity of HaifaHaifaIsrael

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