Recent Expansion of Heat-Activated Retrotransposons in the Coral Symbiont Symbiodinium Microadriaticum

by Chen Jit Ern, Cui Guoxin, Wang Xin, Liew Yi Jin, Aranda Manuel
Year: 2017


​Chen, Jit Ern, Guoxin Cui, Xin Wang, Yi Jin Liew, and Manuel Aranda. "Recent Expansion of Heat-Activated Retrotransposons in the Coral Symbiont Symbiodinium Microadriaticum." The ISME Journal 12 (10/20/online 2017): 639.


​Rising sea surface temperature is the main cause of global coral reef decline. Abnormally high temperatures trigger the breakdown of the symbiotic association between corals and their photosynthetic symbionts in the genus Symbiodinium. Higher genetic variation resulting from shorter generation times has previously been proposed to provide increased adaptability to Symbiodinium compared to the host. Retrotransposition is a significant source of genetic variation in eukaryotes and some transposable elements are specifically expressed under adverse environmental conditions. We present transcriptomic and phylogenetic evidence for the existence of heat stress-activated Ty1-copia-type LTR retrotransposons in the coral symbiont Symbiodinium microadriaticum. Genome-wide analyses of emergence patterns of these elements further indicate recent expansion events in the genome of S. microadriaticum. Our findings suggest that acute temperature increases can activate specific retrotransposons in the Symbiodinium genome with potential impacts on the rate of retrotransposition and the generation of genetic variation under heat stress.


Retrotransposon Symbiodinium Expansion Events