The stress response is an adaption that helped humanity early on, however, parts of this response are no longer as essential as they once were. Studies have shown that intense, long, or repeated stress can lead to maladaptive reactions, including post-traumatic stress disorder and depression. After experiencing a large amount of stress or prolonged stress, the brain tries to adapt to this new context, ultimately leading to changes in gene expression. Such changes can be identified by comparing expression of genes in stressed subjects versus subjects that are not stressed. Our research, which follows a 2020 study on mice brains exposed to a variety of different kinds of stress, aims to split different psychosocial stress types into basic types – acute, subchronic, and chronic stress – and identify any shared gene ‘signatures’ for stress in different contexts. After analyzing the data, we identified two genes with a significant change in all three basic types of stress (Arc and Ciart) and limited sets of genes with shared changes in expression in the different stress types. Arc is found to be strongly upregulated in acute stress and downregulated in chronic stress, while Ciart is downregulated in acute stress and upregulated in chronic stress. Our finding points to the idea that there are some shared genes that are important in acute vs prolonged (chronic) stress, but that their expression ‘switches’ over the course of the adaptive response.

Every bacterial cell contains protein secretion systems which are essential to their propagation and survival. The Type VII secretion system (T7SS) is required for virulence in some Gram-positive bacteria. Proteins secreted by the T7SS include the WXG100 family of proteins and the deadly LXG toxins that will terminate nonkin cells without the cognate anti-toxin. Bacillus subtilis encodes its T7SS and primary substrate on a single operon, the yuk operon. Additional substrates are encoded on other WXG/LXG operons. Recently, competition assays demonstrated that using attacker strains with the T7SS knocked-out allowed the prey to survive. This showed that the LXG toxins are substrates of the T7SS. Little is known about these proteins; one outstanding question is about when the bacterium is using these toxins to enact their effect. To answer this, we will directly test the expression of WXG/LXG operons in various environmental and cellular conditions using transcriptional fusions of each WXG/LXG operon promoter with a GFP reporter. Further, we will combine these reporters with knock-outs of key regulators, such as degU or spo0A, which have shown positive or negative regulation on the yuk operon. Expression of the reporters will be determined by measuring the GFP emissions from cell culture in a plate reader and by fluorescence microscopy. Results from these expression studies will reveal regulation profiles of each of the WXG/LXG operons. This data will directly inform on the conditions in which the bacteria may be using these LXG toxins.

Gregarines are protistan parasites in the phylum Apicomplexa that parasitize the intestinal epithelia of nearly all invertebrate clades. Blabericola migrator is a species of Gregarine that solely infects Madagascar Hissing Cockroaches. Gregarines are most closely related to Cryptosporidians, which infect vertebrates and most notably cause cryptosporidiosis in humans. Gregarines’ similar lifestyle and life cycles to Cryptosporidians, allow the largely understudied parasites to serve as a model for these human infectious parasites. Similar to Cryptosporidians, Gregarines have distinct internal stages: the sporozoites, trophozoites (immature and mature), and those in syzygy. To date, RNAseq analysis has only been completed on Gregarines in a mixed population of internal stages mainly comprised of trophozoites. This generalized transcriptome fails to distinguish between the specific genes expressed at each internal stage; therefore, to develop a stage-specific Gregarine transcriptome, we isolated three distinct subpopulations of internal stage Gregarines: (1) immature trophozoites attached to host epithelial cells, (2) mature, unattached trophozoites, and (3) those in syzygy. We isolated RNA from 4 biological replicates of each subpopulation and submitted the samples for mRNA sequencing. Each subpopulation’s transcriptome will be compared to one another and to the recently published mixed internal stage’s transcriptome to identify how gene expression is altered throughout the maturation of internal Gregarine parasites. Alongside Dr. Charles Hauser, mapping and analyses of stage-specific gene expressions are underway. Preliminary results show success of RNA extraction with quality scores estimating 99.9% - 99.99% correct base sequence and error rates ranging from 0.02% - 0.03% for all samples.