The curious habit of vomiting its viscera at predators may mean the lowly sea cucumber holds the key to a clearer understanding of the genetic basis of self-regeneration, according to scientists who have recently mapped the sea cucumber genome.
Sea cucumbers are ocean-dwelling, bottom feeding echinoderms, like starfish and sea urchins, but possess the unique ability to ‘re-grow’ their intestines within a couple of weeks of expelling them as part of a defense mechanism. This new research aims to use genetics to understand how they are able to do this, and whether this can affect the future of regenerative medicine. To explore the genetic influence of this bizarre skill, Chinese scientists performed high-definition genomic sequencing of the sea cucumber Apostichopus japonicus (also known as the Japanese sea cucumber), covering about 92 percent of its estimated 880 megabases of DNA, including more than 30,000 genes. They identified a group of genes that were specifically expressed in the regenerating intestines of the sea cucumber, which had no corresponding genes in other echinoderms, suggesting that these genes may be responsible for the sea cucumber’s ability to quickly regrow their intestines.
Although not exactly the beauty queen of the oceans, the sea cucumber has been revered by China and other Asian countries as a delicacy and nutritional supplement for centuries. However, it’s starring role may become that of research tool to examine what its unique genome teaches us about regeneration and evolution.
"The sea cucumber is a particularly promising model animal for regenerative medicine and the availability of its genome should aid efforts to study the biology of regeneration and determine if echinoderm regrowth can offer insights that can be applied to human medicine. "