Elucidation Of The Role Of Nitric Oxide During Contractile Ring Formation In Drosophila melanogaster Embryo Development

Nitric oxide synthases (NOS) generate nitric oxide (NO) that signals during physiological activities such as skeletal muscle regeneration; the NO signal also regulates cell proliferation during Drosophila melanogaster embryo development. NOS is associated with monomeric actin to raise its enzymatic activity, suggesting that NO signaling may act during cytokinesis, driven by actin filament contractile ring contraction. Real time imaging analysis of NO signal changes during mitosis/cytokinesis has not yet been explored. I aim to identify the role of NO during cytokinesis by first using fluorescent microscopy to characterize the expression of NO during cytokinesis. Initial studies reveal that when the NO indicator, DAF-FM, was used to monitor chicken ectoderm NO signaling by time-lapse confocal imaging, NO signal was dynamic in the stages leading to cytokinesis. To further assess the presence of NO during cytokinesis, I plan to investigate this phenomenon in Drosophila S2 cells using double stranded RNAi inhibition, as well as during cortical divisions during early Drosophila embryo development. After the presence of NO during cytokinesis has been established, I will determine the potential role of NO during actin remodeling. To achieve this goal, I plan to inhibit NO and determine if actin remodeling during cytokinesis is affected. Additionally, I will investigate NO localization in Drosophila embryos deficient for actin-associated factors necessary for cytokinesis. If NO is identified as a molecular regulator of actin remodeling, then we will be closer to elucidating the full mechanism behind cytokinesis and determining the molecular mechanisms that, if disrupted, can cause cytokinetic defects.