Role of miR-190 on Cell Fate Determination During Mitosis in Drosophila Neuroblasts
By: Gerson Ascencio
Department: Biology
Faculty Advisor: Dr. Blake Riggs
Stem cells in the Drosophila brain, known as neuroblasts, generate most of the neurons in the brain by undergoing asymmetric cell division (ACD). ACD gives a product of two daughter cells that have two separate identities facilitated by cell fate determinants such as aPKC, Prospero, and Numb. These determinants are partitioned asymmetrically to drive cell fate selection, with Prospero moving towards the basal cortex to promote cell differentiation. The mechanism of ACD is highly conserved across all multicellular organisms. However, the organization and regulation of the partitioning of cell fate determinants is poorly understood. Many primary cellular functions such as development, differentiation, growth, and metabolism, are known to be regulated by microRNA (miRNAs). miRNAs regulate gene expression post-transcriptionally by silencing gene expression of targeted mRNA transcripts. We hypothesize that miR-190 regulates ACD. Our qPCR data highlighted Prospero, a transcription factor, as a potential target transcript for miR-190. We showed a shift from stemness to differentiation in neuroblasts and quantified the downstream effects of Prospero being derepressed under miRNA knockout conditions. Our data shows an increased Prospero expression which induces more differentiated progenitor cells of the neuroblast lineage. This data may suggest that miR-190 is a critical regulator in stem cell fate and differentiation and plays a vital role in maintaining the stem cell microenvironment. miRNAs have been discovered to play a role in neurogenerative diseases. Finding how mir-190 plays a role in ACD in Drosophila could lead us to discover new therapeutic agents for neurogenerative diseases.