Monitoring Mitochondrial Age Of Drosophila Intestinal Stem Cells By MitoTimer

MitoTimer is a probe that can monitor mitochondrial aging and mitochondrial turnover in real time.It is called mitochondrial timer fusion protein.The Timer gene encodes a mutant of DsRed fluorescent protein,which sends out green fluorescence when the protein is new,and in the process of protein maturity,its fluorescence spectrum is irreversibly transferred to red as time goes on.Therefore,the physical properties of Timer protein enable it to report the age and update of protein.So when the Timer reporter gene is connected to a pilot peptide Mito that can lead the fluorescent protein into the mitochondrial matrix,it can indicate the age of the mitochondria and the turnover of the mitochondria,which can be used to evaluate the quality of a single mitochondrial or intracellular mitochondrial population.In this paper,we take the intestinal stem cells of Drosophila as the experimentalobject,and monitor the mitochondrial quality of intestinal stem cells in real time with MitoTimer.We found that the quality of mitochondria in the intestinal stem cells of the adult female and male Drosophila is different.It is shown that the Red/Green Ratio of the MitoTimer of the intestinal stem cells of the female flies is smaller than that of the male flies,suggesting that the quality of the mitochondria in the intestinal stem cells of the female flies is more active than that of the male flies.By studying the distribution of mitochondria in the asymmetric division of stem cells,it is found that the stem cells are more inclined to distribute the more new mitochondria to ISC during the asymmetric division.Further analysis showed that the stem cells of female flies produced more EC cells through asymmetric division,suggesting that the stem cell division of female flies may be more frequent.The possible mechanism of the difference in the mitochondrial quality of the intestinal stem cells of the male and female flies is that the division of the intestinal stem cells of the adult female flies is more frequent and the stem cells of the stem cells are more inclined to distribute the more new mitochondria to ISC in the process of asymmetric division,so the intestinal stem cells of the female flies have the more new mitochondria.In spite of this,the mitochondrial quality of the intestinal stem cells of the adult male and female Drosophila also appear to same under the control of PINK1.In this article,we set up a method for monitoring the mitochondrial quality ofintestinal stem cellsof Drosophila in real time.It provides a new idea for the study of mitochondrial quality in stem cells.And we found there are differences in the quality of mitochondria in the intestinal stem cells between male and female Drosophila,and discussed the possible mechanisms.