Ly, Christine (2020)
      During retinal development, a pool of progenitor cells divides to generate daughter cells that eventually differentiate into the seven retinal cell types, including horizontal cells (HCs) and retinal ganglion cells (RGCs). Much about how cells exit the cell cycle and maintain a differentiated state remain unknown. Dysregulation of this process can alter the cellular composition and function of the retina.Thus, by studying this developmental process, we can better understand the mechanisms by which progenitor cells become functional, differentiated cells. Our previous work determined that Maturin (Mturn)is highly conserved in its expression pattern and protein sequence across various vertebrate species. Furthermore, we concluded that it is required for differentiation of primary neurons in Xenopuslaevis. Preliminary work in mice revealed that in the absence of Mturn, extensive folds occur in the retina. I used this model to characterize the expression of Mturnin the mouse retina and ask if Mturn is required for normal mice retinogenesis. By immunostaining retinal sections with various cell type-specific antibodies, I found that Mturn is expressed in differentiating cells and not in proliferating cells. In addition to determining that its expression is maintained in mature HCs, I concluded that Mturn is not required for generating the proper number HCs. Our results from studies on Mturn in both frogs and mice have led us to hypothesize that Mturn may function to maintain HCs in differentiated state and prevent their reentry into the cell cycle. Although preliminary experiments testing this hypothesis were inconclusive, future work should continue to investigate the role of Mturn in retinogenesis.