Abstract
Meiosis is a specific type of cell division that is essential for sexual reproduction in most eukaryotes. Mitochondria are crucial cellular organelles that play important roles in reproduction, though the detailed mechanism by which the mitochondrial respiratory chain functions during meiosis remains elusive. Here, we show that components of the respiratory chain (Complexes I-V) play essential roles in meiosis initiation during the sporulation of budding yeast, Saccharomyces cerevisiae Any functional defects in the Complex I component Ndi1p resulted in the abolishment of sporulation. Further studies revealed that respiratory deficiency resulted in the failure of premeiotic DNA replication due to insufficient IME1 expression. In addition, respiration promoted the expression of RIM101, whose product inhibits Smp1p, a negative transcriptional regulator of IME1, to promote meiosis initiation. In summary, our studies unveiled the close relationship between mitochondria and sporulation, and uncover a novel meiosis initiation pathway that is regulated by the respiratory chain.