MEPS 275:97-102 (2004)  -  doi:10.3354/meps275097

Distinct ITS types of Symbiodinium in Clade C correlate with cnidarian/dinoflagellate specificity during onset of symbiosis

Mauricio Rodriguez-Lanetty1, Dave A. Krupp2, Virginia M. Weis1

1Department of Zoology, Oregon State University, Oregon 97331, USA
2Department of Natural Sciences, Windward Community College, Kaneohe, Hawaii 96744, USA

ABSTRACT: This study aimed at determining whether fine-scale molecular diversity of Symbiodinium corresponds to functional differences in host/symbiont specificity during the onset of symbiosis in cnidarian/alga mutualisms. Infection experiments were conducted in aposymbiotic larvae of the scleractinian Fungia scutaria using known algal Internal Transcribed Spacer (ITS)-2 types within Clade C. Our results show that algal type is directly related to specificity during the onset of symbiosis in F. scutaria larvae. The 3 ITS symbiont types (C1f, C15 and C31) within the major Symbiodinium Clade C engaged differentially in symbiosis with coral larvae. The homologous symbiont (C1f), found in adult F. scutaria from the field, showed a significantly better association with the host larvae than the other 2 heterologous symbionts (C15 extracted from Porites compressa, and C31 from Montipora capitata). This is the first evidence that fine-scale ITS diversity of Symbiodinium confers functionality in the symbiosis.


KEY WORDS: Symbiosis · Specificity · ITS-2 types · Symbiodinium · Scleractinia


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