By Amy Maxmen
Every horror flick fan knows to never underestimate a blob. Now, scientists working with comb jellies have learned the same lesson. Within the transparent ooze of the gelatinous animal, researchers have found startling genetic complexity. It’s as if they’ve discovered that igloos were based on blueprints for the Sydney Opera House.
No one suspected that the primitive comb jellies — watery, rotund and nearly invisible sea creatures — would rely on an intricate interplay of genes to design their rudimentary bodies. Yet researchers got a surprise when they looked at the comb jelly’s genes. Scientists found pattern-making genes that, in most animals, plot out the position of the head, brain, limbs and rear ends during development. These “homeobox” genes turned on in a specific pattern in the comb jellies, even though these ancient sea creatures are headless, brainless, limbless and rear end–less, scientists show in the June Development Genes and Evolution.
This perplexing discovery suggests that simple creatures have more going on genetically than what meets the eye. It also suggests that genes that play similar roles in most animals perform very different functions in comb jellies or may not produce any visible outcomes at all.