A cross-section through the specialized organelle of Ancoracysta called the “ancoracyst,” which is hypothesized to function as a gun used to immobilize prey cellsDENIS TIKHONENKOV / RUSSIAN ACADEMY OF SCIENCESFrom an aquarium at the Scripps Institution of Oceanography in San Diego, California, scientists have identified a unicellular species that could shed light on how eukaryotes evolved, they report in Current Biology this week (November 22). The tiny organism—named Ancoracysta twista—is not only its own species, says lead author of the study, Jan Janouškovec, but “it represents a whole new lineage in the eukaryotic tree of life.”
A. twista is about 10 micrometers long and moves by using its whip-like flagellum. It is named after its distinguishing feature—the “ancoracyst,” a gun-like organelle that it uses to “shoot” at and immobilize its prey, usually other flagellate species. Janouškovec, a molecular biologist at University College London, along with an international team of scientists, discovered A. twista in a sample collected from the surface of a brain coral in a tropical aquarium.
The researchers realized that Ancoracysta represents its own lineage when phylogenetic models could not reconcile its genetic material with that of any existing lineages. Ancoracysta is a protist, a group of unicellular, eukaryotic organisms that sit at the root of the eukaryotic tree of life. For researchers such as Janouškovec, they are an ...
