Host-pathogen interactions are an aspect of ecosystems but the rapid change of the environments has challenged organisms to adapt quickly. In my research, I investigated how nucleopolyhedrovirus (NPV) affects the reproduction of the Gulf Fritillary Butterfly, Agraulis vanillae, on drought-stressed Passiflora caerulea. NPV infects individuals at larval stage, when larvae consume the virus on contaminated P. caerulea leaves. Larvae grew in controlled environments where they were selected at random for a diet of high water or drought-stressed plants. We then infected larvae with one of four virus doses. Pupae were collected and survivors mated within their diet and infection treatment groups after they emerged as butterflies (n= 27 females and n= 17 males). Male and female mating success was determined as a binomial (yes/no) trait, based on whether a mating led to laying of fertile eggs. We found that in the absence of the virus, there was no difference in female mating success between butterflies raised on drought-stressed plants and those raised on high-water plants. However, in the presence of the virus, female butterflies raised on drought-stressed plants had higher mating success (logistic regression, virus by water treatment interaction effect= 19.58, LR= 4.72, p=0.03). This experiment has shown that pathogens and the effects of climate change in the form of drought can influence mating success and oviposition in a butterfly. Thus, the presence of pathogens negatively influences population growth of butterflies through increases in larvae mortality, butterflies that survive exposure see an increase in fitness.

The Blood Brain Barrier (BBB) acts as a semi permeable layer around the blood vessels within the brain that regulates movement of molecules between the blood and the brain. Vascular smooth muscle cells and pericyte-like cells, also collectively called mural cells, regulate development of the BBB. Compared to in vivo samples, in vitro models of human brain mural cells show reduced expression in important mural cell genes, including NOTCH3. The differentiation process of pericyte-like cells derived from NCSC is not well understood. In this study, we explore if NOTCH3 signaling in hPSC derived neural crest stem cells (NCSC) can direct differentiation of brain mural pericyte-like cells. There are multiple methods to do this differentiation. Many use serum supplemented media, thus it can be said they are undefined methods. hPSC derived Neural Crest treated with Lentivirus that includes Notch3 intracellular domain (N3ICD) and GFP are seen to have differentiation of cells that have brain mural cell properties. N3ICD expression can be known by expression of green fluorescent protein (GFP) that is also in the Lentivirus. Our next steps include generating a dox-inducible line to have the ability to control the timing of N3ICD expression and levels of expression. Additionally, cells won’t need to undergo FACS to purify N3ICD expressing cells.

Polymerization of the cytoskeletal protein actin into branched filament networks generates forces that power cell movement. These branched networks sense and respond to external forces and adapt by altering the branch density. The Arp2/3 complex is a complex of 7 proteins including 2 actin-related proteins that bind and hydrolyze ATP (Arp2 and Arp3) that nucleate new branches (referred to as “daughter” filaments) on existing “mother” filaments. Abnormal expression of Arp2/3 subunits has been linked to the proliferation and pathology of various cancers and neurological dysfunctions. It is crucial to comprehend Arp2/3's structural and functional characteristics as well as the molecular processes that control its activity if we are to understand the molecular origins of these disorders and develop novel treatment approaches. Of particular relevance is how the stability of these branched networks responds and adapts to force. Past research on the pombe Arp2/3 complex shows that branches are sensitive to force. It also shows that the Arp2/3 complex, similar to actin, “ages” when it releases gamma phosphate from hydrolyzed ATP and becomes more sensitive to force. However, there is no general census on which Arp2/3 subunits are the aging sensor(s). We are hoping to ask about the consistency of these results in the human Arp2/3 complex and address the question of whether mutant Arp 2/3, specifically which subunits, would affect the stability and mechanical properties of debranching.