Long Oskar Controls Mitochondrial Inheritance in Drosophila melanogaster

Abstract

<p id="P1">Inherited mitochondrial DNA (mtDNA) mutations cause severe human disease. In most species, mitochondria are inherited maternally through mechanisms that are poorly understood. Genes that specifically control the inheritance of mitochondria in the germline are unknown. Here, we show that the long isoform of the protein Oskar regulates the maternal inheritance of mitochondria in <i>Drosophila melanogaster</i>. We show that during oogenesis mitochondria accumulate at the oocyte posterior concurrent with the bulk streaming and churning of the oocyte cytoplasm. Long Oskar traps and maintains mitochondria at the posterior at the site of primordial germ cell (PGC) formation through an actin-dependent mechanism. Mutating <i>long oskar</i> strongly reduces the number of mtDNA molecules inherited by PGCs. Therefore, Long Oskar ensures germline transmission of mitochondria to the next generation. These results provide molecular insight into how mitochondria are passed from mother to offspring, and also how they are positioned and asymmetrically partitioned within polarized cells. </p><p id="P2">Mitochondria are inherited maternally through poorly understood mechanisms. Hurd et al. show that the long isoform of Oskar protein specifically controls mitochondrial germline inheritance in <i>Drosophila melanogaster</i>. Through an actin-dependent mechanism, Long Oskar traps mitochondria where the cells that give rise to the next generation form, ensuring efficient mtDNA inheritance. </p><p id="P3"> <div class="figure-container so-text-align-c"> <img alt="" class="figure" src="/document_file/968cc3ae-cc4c-4ff7-8268-07fdc364036b/PubMedCentral/image/nihms828987u1.jpg"/> </div> </p>