1. Session [VI] : Basic and Applied Zoological Researches
The Third International Conference on New Horizons in Basic and Applied Science (ICNHBAS) 5-7 August, Hurghada, 2017
Molecular phylogeny of Symbiodinium spp. within selected soft coral genera in the Red Sea, Egypt
Hadeer A. Ismail1, Mohammed I. Ahmed2, Fedekar F. Madkour1 and Mahmoud H Hanafy2
1 Department of Marine Science, Faculty of Science, Port Said University, Egypt
2Department of Marine Science, Faculty of Science, Suez Canal University, Ismailia, Egypt
Abstract
Materials and Methods
Phylogenetic clades and diversity of Symbiodinium within soft coral (Octocorallia: Alcyonacea) hosts were investigated using the analysis of nuclear gene sequence ITS2 and chloroplast gene sequence variation at the ribosomal large subunit 23S Domain V. A total of 29 soft coral samples of the genera Sinularia, Sarcophyton, Lobophytum, Xenia and Nephthea were collected from two sites, Lighthouse in the Gulf of Aqaba and Marsa Egla in the northern Red Sea during summer 2015 at three depths. The results revealed that three subclades of Symbiodinium were detected within soft coral hosts; C1 was found within three genera Sinularia, Sarcophyton and Xenia, C3 found in Lobophytum and A3 in Nephthea.
1.Sample collection
Five soft corals genera; Sinularia, Sarcophyton, lobophytum, Xenia and Nephthea; were collected from Gulf of Aqaba (Light house) and northern Red Sea (Marsa Egla) in summer 2015 ( Fig. 1).
2.DNA extraction, amplification and sequencing
DNA extraction was conducted using Phenol/Chloroform Extraction Method (PC) as described by Coffroth et al. (1992) with some modifications for zooxanthellae DNA extraction. PCR amplification of Symbiodinium genotyping was performed to sub-clades using two genetic markers; nuclear ITS2that described by LaJeunesse and Trench, (2000) but without GC clamp and chloroplastic primer 23S Domain V (cp23S rDNA) which was modified from the protocols in Zhang et al. (2000) .
Introduction
Results
Soft corals are an important component of coral reef assemblages, providing a source of food besides habitats for other organisms and contributing to primary productivity (Fabricius and Alderslade 2001). Diversity within the genus has been characterized at many taxonomic levels and the genus has been partitioned into 9 clades abbreviated as A-I (LaJeunesse, 2014).
This study aims to persist some of Symbiodinium phylogenetics among major clades harbored by some soft corals of the Egyptian Red Sea that could help in increase more information about Symbiodinium diversity.
This had been succeeded to partially resolve Symbiodinium genetic diversity in proper Red Sea by identifying molecular structure of endosymbiotic systems of some common coral species. Only two Symbiodinium clades, A and C, had been identified from different soft coral genera along wide geographic area between 0-10m depths during summer.(Fig.2), (Fig.3) and (Fig.4).
Figure 2. ITS2 Phylogenetic relationships inferred by Neighbor-Joining method between members of Symbiodinium harbored by different taxa of invertebrates in the Red Sea
(a) (b) (c)
(d) (e)
Figure 1. zooxanthellate soft coral genera collected for Symbiodinium identification respectively, (a) Sarcophyton, (b). Xenia , (c ) Nephthea, (d ) Sinularia and (e ) lobophytum)
Conclusion
Data on the genetic diversity of Symbiodinium clades hosted soft corals in the Red Sea will yield further information on how the observed specificity pattern emerged especially in soft corals. Subsequently, many studies are needed to increase the database of Symbiodinium diversities in the Proper Red Sea
Figure 3. Phylogenetic tree of Symbiodinium from Sinularia and Lobophytum based on Neighbor-Joining method of 23S sequences
Figure 4. Phylogenetic tree of Symbiodinium from Xenia, Sarcophyton and Nephthia based on Neighbor-Joining method of ITS2 sequences
References
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Fabricius KE, Alderslade P (2001) Soft corals and sea fans. Australian Institute of Marine Science. Townsville: Australian Institute of Marine Science. 264 pp.
LaJeunesse TC, Trench RK (2000) Biogeography of two species of Symbiodinium (Freudenthal) inhabiting the intertidal sea anemone Anthopleura elegantissima (Brandt). Biol. Bull., 199, (2)
LaJeunesse, T.C.; Wham, D.C.; Pettay, D.T.; Parksinson, J.E.; Keshavmurthy, S.; Chen, C.A. (2014) Ecologically differentiated stress-tolerant endosymbionts in the dinoflagellate genus Symbiodinium (Dinophyceae) Clade D are different species. Phycologia, 53, 305–319.
Zhang Z, Green BR, Cavalier-Smith T (2000) Phylogeny of ultra-rapidly evolving dinoflagellate chloroplast genes: a possible common origin for sporozoan and dinoflagellate. .
Session [VI] : Basic and Applied Zoological Researches
5-7, August, 2017