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Vol. 41 No. 3, 2002
Genotyping the Clonal Population Structure of a Gorgonian Coral, Junceella fragilis (Anthozoa: Octocorallia: Ellisellidae) from Lanyu, Taiwan, Using Simple Sequence Repeats in Ribosomal Intergenic Spacer
Chaolun Allen Chen1,2,*, Nuwei Vivian Wei1,2 and Chang-Feng Dai2
1Institute of Zoology, Academia Sinica, Nankang, Taipei, Taiwan 115
2Institute of Oceanography, National Taiwan University, Taipei, Taiwan 106
Chaolun Allen Chen, Nuwei Vivian Wei and Chang-Feng Dai (2002) Asexual
reproduction allows clonal genotypes to dominate a space and plays an
important role in the ecology and evolutionary biology of many
anthozoans. To analyze the contribution of clonality to local
population structure requires genetic markers that can identify
individual clones (genets). We explored the possibility of developing
coral-specific PCR primers to amplify a region of tetranucleotide
simple sequence repeats (SSRs, also known as microsatellites) in the
ribosomal intergenic spacer (IGS) region. A primer set for PCR
amplification of the IGS-SSR, A(C/G)(A/C)G, was designed and applied to
investigate the clonal structure of 30 colonies of the gorgonian coral,
Junceella fragilis, from
Lanyu (Orchid Island) off southeastern Taiwan in 1999. In total, 12
scorable bands (length variants) and 2 distinct genotypes were
identified. Of the colonies sampled, 66.67% represented a single
dominant genotype. Low genotypic diversity revealed by several indices (G0, G0: GE, and Nc / N) supports the scenario that the success of J. fragilis
around Lanyu is likely due to vegetative propagation. The presence of 2
distinct genotypes sharing no common IGS length variants indicates that
these 2 genotypes may have played the role of founders in structuring
the Lanyu local population. The present study highlights the potential
utility of IGS-SSR PCR techniques in delineating clonal diversity in J. fragilis populations on both local and global scales.
Key words: Microsatellites, Junceella fragilis, Genotypic diversity, IGS-SSR, Asexual reproduction.
*Correspondence: Tel: 886-2-7899549. Fax: 886-2-7858059. E-mail: cac@gate.sinica.edu.tw
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