Drosophila modeling to identify causative genes and reveal the underlying molecular mechanisms for primary ovarian insufficiency.

Abstract

Primary ovarian insufficiency (POI) is a disease defined as a reduction in ovarian function under the age of 40 and represents the main cause of female infertility. In recent years, many genetic mutations associated with POI have been identified using high-throughput sequencing technology. However, one big challenge today is to determine the disease-causing gene associations through functional assessment. Here, we develop a Drosophila model to study the POI-associated genes and provide in vivo functional evidence to validate the POI-causing genes. We use two different Gal4 drivers, in combination with RNAi transgene, and systematically knockdown 51 genes associated with POI. We show that 22 and 17 genes are required for female fertility and ovarian development in somatic and germline cells, respectively. Moreover, we also focus on AlaRS-m, the Drosophila ortholog of the human AARS2 gene, for further functional characterization. Depletion of AlaRS-m in ovarian somatic cells leads to decreased female fertility and a reduction in ovary size, as well as egg chamber degeneration. We also provide evidence that AlaRS-m deficiency causes mitochondrial dysfunction, overproduction of ROS, and apoptotic cell death. Our findings demonstrate that Drosophila can be used as a platform to assess the functional significance of POI-associated genes identified in genomic studies and illustrate the molecular mechanism underlying the pathogenesis of POI. KEY MESSAGES: • One hundred fourteen genes associated with POI are identified, and 76 of them have Drosophila orthologs. • Twenty-two genes and 17 genes are required for female fertility when knocked down in the Drosophila ovarian somatic cells and germline cells, respectively. • AlaRS-m/AARS2 deficiency causes female fertility defects with egg chamber degeneration.