Complex epithelial tissues are composed of a variety of differently shaped cells, each with distinct three-dimensional architectures integral to their functions. However, the molecular mechanisms that contribute to the generation of these cell-type specific underlying structures remains elusive. To unravel these developmental mechanisms, we are investigating the relationship between cell type-specific expression of cytoskeletal genes and the formation of distinct cytoskeletal structures in the Drosophila pupal eye, which consists of 4 different cell types. Here, specifically we have identified a unique cytoskeletal structure found in the eye's primary (1˚) pigment cells that we termed Apical Radical Actin Filaments (ARAFs). To characterize and verify our previous characterizations of ARAFs, a protocol for live-imaging tissue is generated. Live imaging revealed that apical-cortical actin is visible from 30 h after puparium formation (APF), and ARAFs are first observed at 37 h APF. As we hypothesized that ARAFs are highly bundled structures, we investigated the role of actin-bundling proteins Quail and α-Actinin, which colocalize along ARAFs. Reducing Quail and α-Actinin levels leads to perturbation of ARAF architecture and primary cell area. We found that when Quail is reduced at 40 h APF, primary cell area decreases, whereas reducing α-Actinin levels at 40 h APF led to an increase in primary cell area. When Quail and α-Actinin levels were simultaneously reduced, we found that there was no significant change in 1˚ cell area, suggesting that Quail and α-Actinin may be competing to promote the assembly of distinct cytoskeletal structures that either reinforce the expansion of or counter the expansion of the 1˚cell apical membrane. By understanding the mechanisms by which actin cross-linking proteins contribute to the formation and regulation actin cytoskeletal structures, we can further our understanding on the processes by which cells obtain a desired size, shape, and mostly importantly, their function.
"},{"label":"Degree","value":["Bachelor of Arts with Departmental Honors"]},{"label":"Author-supplied Keywords","value":["Drosophila","Actin","Development"]},{"label":"Administrative Note","value":"Drupal Node ID: 33982