They live at extreme opposite ends of the planet but thanks to ocean currents they stay in contact with one another thus guaranteeing a common genetic heritage. They are Euplotes nobilii, a species of marine micro-organism with a marked gift of adaptation at very low temperatures which, as the name itself says – from the Greek, 'good navigator' – move through the oceans from the South Pole to the North Pole while ensuring interactions of a conspecific nature, potentially significant as indices of climatic change in progress.
This important discovery was made by Graziano Di Giuseppe, Professor of Protistanology at the University of Pisa, who, together with a team of researchers, analysed the physiological-behavioural nature of 18 families of the ciliate Euplotes nobilii in the sediments of the coastal waters of the Antarctic areas (Bay of Newfoundland, The Ross Sea and Tierra del Fuego seas) and Arctic areas (The Svalbard Islands and north-western Greenland).
This research has shown that the South Pole-North Pole exchange between the conspecific populations of Euplotes nobilii takes place via passive transport of individuals from the deep parts of ocean currents characterised by low temperatures. Furthermore, recognition among individuals for coupling, with the objective of interpolar genetic exchange, is mediated by liberated molecules in the atmosphere (pheromones) whose efficiency in guaranteeing sexual recognition of partners is limited to a few units if not to a uniqueness. The structure of these molecules of a proteinic nature is surprisingly stable and supports very broad variations of temperature.
The results obtained by Di Giuseppe, from the Department of Biology at the University of Pisa, were reached thanks also to the availability at the centre in Via Volta of the most consistent collection presently in existence of protistans 'a vita libera' : eucariotic, cosmopolitan and ubiquitous unicellular organisms, representatives of the first great evolutionary and ancestral leap of all the higher vegetable, animal and fungus-like multi-cellular organisms.
The characteristics of Euplotes have drawn the interest of Kurt Wuthrich, Nobel Prize winner for chemistry in 2002, who, in association also with protistologists of the 'Camerino' group – a branch of the one in Pisa, contributed to the conclusion of a paper recently published in a prestigious scientific journal: The Proceedings of the National Academy of Sciences USA.