Autocrine mitogenic activity of pheromones produced by the protozoan ciliate Euplotes raikovi

摘要: DIFFUSIBLE polypeptide pheromones (formerly referred to as mating-type factors, sex factors or gamones), which distinguish otherwise morphologically identical vegetative cell (mating) types from one another, are produced by some species of ciliates1,2. Their most striking effect can be observed exposing cells type a pheromone secreted another co-specific type3. In the presence this a¤˜non-self a¤™ signal, these interrupt their life unite temporarily in mating pairs. Thus ciliate have traditionally been associated only with induction2,4. However, identification autocrine receptors5,6 suggests broader role, is supported hypothesis that ciliates evolved mechanism for pursuing self-recognition1. We now report studies, cosmopolitan marine sand-dwelling protozoan Euplotes raikovi, demonstrating molecules promote reproduction (mitogenic proliferation growth) same they originate. As, understandably, such activity primary targeting and inducing foreign mate (paracrine functions), finding provides an example how original function molecule obscured during evolution acquisition new one.