Meeting Abstract

16.5  Jan. 4  A nuclear genome perspective on species boundaries and population structure in the sea anemone Aiptasia spp. XIANG, Y*; SANTOS, S.R.; Auburn University; Auburn University santos@auburn.edu

Many marine invertebrates form mutualistic symbioses with dinoflagellates belonging to the genus Symbiodinium. To better understand these symbiotic associations, there is a need to develop model systems that are well characterized for both the symbiont as well as their host. One potential model system involves the symbiosis between the common sea anemone Aiptasia and their Symbiodinium partner. However, genes from the mitochondrial genome of many cnidarians have been found to evolve relatively slowly when compared to other animals, hindering their use as species and/or population level genetic markers. In order to define potential species boundaries and fine-scale genetic structure within Aiptasia spp., random nuclear genomic fragments were isolated via inter-simple sequence repeat (ISSR) techniques from aposymbiotic hosts. Following characterization of common and private fragments obtained from A. pulchella (Hawaii) and A. pallida (Florida Keys), seven sequence characterized amplified region (SCAR) markers were developed which are genetically variable between and within species and/or populations. Currently, these markers allow differentiation between homozygote and heterozygote individuals, as well as provide information regarding the genetic structure of Aiptasia spp. Surprisingly, no fixed genetic differences have been identified between A. pulchella and A. pallida, suggesting that they may belong to a single, panmictic, species. These genetic markers will not only serve as a powerful tool in this model cnidarian-dinoflagellate symbiosis, but also in developing a better understanding of genetic structure and connectivity in marine invertebrate species and populations.