Zikadenendosymbiose: Eucyten-Struktur-, -Funktions- und -Evolutions-Modell

Summary The mitochondria can be considered as extremely integrated endosymbionts, according to the theory of the endosymbiontic origin of eucytes. Leafhoppers show also very integrated endosymbionts. Their protoplastoid-, rickettsia-and bacteria-like endosymbionts differ, according to grade, kind and supposed age of the relation, from the hypothetical type of mitochondria. Mitochondria and protoplastoids differ the least and show corresponding physiological behavior. Both have a regulative influence on pH and osmotic pressure of the eucyte and use probably the same mechanism of regulation. The protoplastoid endosymbiosis of leafhoppers can be regarded as a missing link between the temporary endosymbiosis of the bacteria and the permanent hypothetical one of the mitochondria. The leafhopper endosymbiosis is a suitable model for the analysis of structure, function and evolution of the eucyte.