<i>Tetrahymena</i> ATG8 homologs, TtATG8A and TtATG8B, are responsible for mitochondrial degradation induced by starvation

This study is the first comprehensive description of the mitochondrial degradation process under nutrient starvation in the ciliate <i>Tetrahymena</i>. It is well known that the cell surface structure of ciliates consists of an elaborate spatial arrangement of microtubule networks and associated structures and that this surface repetitive pattern is inherited by the next generation of cells like genetic information. Our findings provide a basis for understanding how ciliates maintain an adequate amount of mitochondria on the cell surface in response to nutritional conditions. Furthermore, we have successfully demonstrated the usefulness of <i>Tetrahymena</i> as an experimental system for studying mitochondrial quality control and turnover. Further studies of <i>Tetrahymena</i> will facilitate comparative studies among diverse biological systems on how eukaryotes other than opisthokonta (yeast, cultured cells, etc.) control their mitochondria.