Japanese researchers have
recently identified the first spontaneous mutant coral symbiont alga that does
not maintain a symbiotic relationship with its host. The alga have devised a
system where the simple addition or depletion of a nutrient can switch the
symbiosis on and off, experimentally. This alga, which is mutant, enables the
development of a genetic transformation system. This system will eventually be
a powerful tool for researchers studying coral-algal endosymbiosis.
Figure 1. Symbiotic and non-symbiotic state of the sea
anemone E.pallida, respectively.
A great source of
biodiversity in the sea is coral reefs. Stable symbiotic relationships between
host cnidarian animals and the symbiont dinoflagellate are what the ecosystem
relies on. Environmental changes due to globing warming can collapse this
symbiosis. An example of this is “coral bleaching”. Understanding mechanisms
for maintaining stable symbiosis is extremely difficult.
Figure 2. Coral Bleaching Reference
The mutant in these coral is
deficient of uracil which is a basic compound of nucleic acid. This has
appeared to have lost the ability to maintain symbiosis with a model organism.
The model organism used in this case is the sea anemone. This is what indicates
the simple addition or depletion of the nutrient which can be used as a switch
for controlling the symbiotic relationship. The next step in this research is
to introduce genetic mutations that are going to be capable of reversing uracil
deficiency in the mutant dinoflagellate. This can hopefully provide clues for
identifying algal genes responsible for symbiosis.
Source for Article and Figure 1: Tohoku University. 2018. New Mutant Coral Symbiont Alga Able to Switch Symbiosis Off. ScienceDaily. https://www.sciencedaily.com/releases/2018/02/180222103416.htm
Figure 2 Source:
http://sites.psu.edu/ichen/wp-content/uploads/sites/38297/2016/04/coralbleaching.jpg
