Transcriptome profiling of Galaxea fascicularis and its endosymbiont Symbiodinium reveals chronic eutrophication tolerance pathways and metabolic mutualism between partners.
In the South China Sea, coastal eutrophication in the Beibu Gulf has seriously threatened reef habitats by subjecting corals to chronic physiological stress. To determine how coral holobionts may tolerate such conditions, we examined the transcriptomes of healthy colonies of the galaxy coral Galaxea fascicularis and its endosymbiont Symbiodinium from two reef sites experiencing pristine or eutrophied nutrient regimes. We identified 236 and 205 genes that were differentially expressed in eutrophied hosts and symbionts, respectively. Both gene sets included pathways related to stress responses and metabolic interactions. An analysis of genes originating from each partner revealed striking metabolic integration with respect to vitamins, cofactors, amino acids, fatty acids, and secondary metabolite biosynthesis. The expression levels of these genes supported the existence of a continuum of mutualism in this coral-algal symbiosis. Additionally, large sets of transcription factors, cell signal transduction molecules, biomineralization components, and galaxin-related proteins were expanded in G. fascicularis relative to other coral species.
School of Life Sciences, Xiamen University; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen, Fujian 361005, China.|State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, State Oceanic Administration; Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China.
Zhenyue
Z
Lin
State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, State Oceanic Administration; Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China.
Mingliang
M
Chen
Laboratory of Marine Chemistry and Environmental Monitoring, Third Institute of Oceanography, State Oceanic Administration, Xiamen, Fujian 361005, China.
Xu
X
Dong
Laboratory of Marine Biology and Ecology, Third Institute of Oceanography, State Oceanic Administration, Xiamen, Fujian 361005, China.
Xinqing
X
Zheng
Laboratory of Marine Chemistry and Environmental Monitoring, Third Institute of Oceanography, State Oceanic Administration, Xiamen, Fujian 361005, China.
Haining
H
Huang
School of Life Sciences, Xiamen University; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen, Fujian 361005, China.|State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, State Oceanic Administration; Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China.
Xun
X
Xu
School of Life Sciences, Xiamen University; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen, Fujian 361005, China.|State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, State Oceanic Administration; Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China.
Jianming
J
Chen
D000818:Animals; D037421:Anthozoa / Q000235:genetics / Q000254:growth & development* / Q000469:parasitology*; D059001:Aquatic Organisms / Q000235:genetics / Q000254:growth & development / Q000469:parasitology; D002681:China; D004141:Dinoflagellida / Q000235:genetics / Q000254:growth & development*; D005068:Eutrophication; D020869:Gene Expression Profiling; D053858:Metabolic Networks and Pathways; D013312:Stress, Physiological; D013559:Symbiosis