Sea Anemones Are Half-Plant, Half-Animal, Gene Study Finds

• The sea anemone is an oddball: half-plant and half-animal, at least when it comes to its genetic code, new research suggests.
• The sea creature's genes look more like those of animals, but the regulatory code that determines whether those genes are expressed resembles that in plants, according to a study published Tuesday (March 18) in the journal Genome Research.
• Researchers from the University of Vienna believe that the sea anemones' genome suggests that their type of gene regulation is 600million years old

• Their genome includes elements that could date back to the common ancestor of humans, flies and sea anemones.
• Scientists discovered that sea anemones are more similar to plants that to vertebrates in their regulation of gene expression.

WHAT ARE SEA ANEMONES?

• Sea anemones are a group of water-dwelling, predatory animals classified in the phylum Cnidaria.
• The polyps stick to the sea floor with an adhesive foot called a basal disk and have a column-shaped body ending in an 'oral disk'.
• Most measure 1.5cm to 3cm in diameter, but some measuring up to two metres have been found.
• They can have up to a few hundred tentacles.
• The creature's mouth is in the middle of its 'oral disk' and is surrounded by tentacles with cells on them that protect the creatures as well as let them catch prey.
• Some of the animals can sting and inject venom into prey such as small fish and shrimp.
• The venom is a mixture of toxins that paralyses the prey so it can be moved to the anemone's mouth for digestion inside its 'gastrovascular cavity,' which functions like a stomach.
• Sea anemones are related to corals and jellyfish.

WHAT ARE GENES?

• Genes are a set of instructions that determine what an organism is like - such as how it looks and how it behaves.
• They lie in strands of DNA called chromosomes and are composed of four different chemical bases, different combinations of which give people and animals different characteristics.
• How genes act together and regulate each other's activity in regulatory networks, also affects an organism's behaviour.
• In the last decades, the sequencing of the human and animal genomes has shown that anatomically simple organisms - such as sea anemones - show a surprisingly complex gene make-up similar to more complex organisms.
• This implies that how complex organisms came to be cannot be easily explained by the presence or absence of individual genes
• How genes are linked together plays a part in how complex creatures are.
• In this experiment, scientists looked at the distribution of regulatory sequences - called enhancers and promoters - in the sea anemone's genome.
• While genes can be likened to the words in the language of genetics, enhancer and promoters serve as the grammar.