BRCA1 is widely recognized for its role in maintaining genomic stability, particularly through its involvement in several DNA repair pathways and chromatin regulation. While mutations in BRCA1 are strongly associated with increased cancer risk in humans, the broader cellular consequences of BRCA1 mutations under environmental stress remain unclear. The goal of the project was to investigate how loss or alteration of BRC-1, the Caenorhabditis elegans (C. elegans) homolog of BRCA1, affects stress responses at the organismal level, with focus on oxidative stress and reactive oxygen species (ROS) accumulation.

Using C. elegans as a model organism allowed me to study the stress responses within a system where development, reproduction, and genome stability are tightly connected. A key advantage of using C. elegans is that the organism is transparent. This allows for visualization and quantification of fluorescence to measure ROS within the worms, and to see how these values vary depending on BRC-1 status. Three strains were compared: 1) wild-type (N2), 2) a BRC-1 mutant (syb5376) predicted to disrupt nucleosome interaction and H2A monoubiquitylation while retaining other enzymatic functions, and 3) double knockout strain (xoe4) lacking functional BRC-1 entirely. The comparison of these worms with various levels of BRC-1 activity allowed for the investigation of how each of these different strains responded to various oxidative stressors. The broader aim of the project was specifically to look at how altered BRC-1 nucleosome ubiquitylation affects the cell's ability to deal with ROS, and compare this with the wild-type and complete knockout.

Several key questions were used to guide the research: 1) Whether stress responses differed between wild-type, mutant, and knockout strains, 2) How oxidative stressors altered ROS levels in each of the strains, and 3) Whether the syb5376 and xoe4 strains behaved similarly or exhibited distinct patterns compared to wild-type worms. Across multiple experimental conditions, the double knockout strain consistently showed the most elevated fluorescence, indicating increased ROS accumulation and reduced ability to manage oxidative stress due to the lack of BRC-1. The syb5376 mutant displayed an intermediate effect, suggesting partial impairment of regulation when lacking nucleosome interaction. These findings support the idea that BRC-1 plays a protective role under stress conditions and that disruption of nucleosome ubiquitylation may compromise the cellular response to oxidative damage and lead to a higher accumulation of ROS within cells.

Looking at the bigger picture, these results align with the broader understanding that BRCA1 loss does not immediately lead to cancer, but rather increases vulnerability when cells are challenged by environmental or metabolic stressors. Increased ROS levels can lead to DNA damage, and without proper chromatin remodeling and repair coordination, cells may struggle to restore their genomic integrity. The differences observed between the mutant and knockout strains further suggest that mutation type matters in determining the severity of stress sensitivity and the overall impact that this will have on the cell and organism as a whole.

This study investigates the phylogenetic relationships among the blueberry species (Vaccinium section Cyanococcus) using whole-genome data from 96 samples representing 21 species, including cultivars and putative hybrids, collected across the eastern United States. Despite the ecological and economic importance of blueberries, evolutionary relationships within the group remain incompletely resolved due to factors such as hybridization, polyploidy, and morphological similarity among species. By applying phylogenomic approaches to genomic data, this research aims to reconstruct a robust species phylogeny and clarify evolutionary relationships within the genus. The phylogeny will provide a framework for understanding diversification patterns in blueberries and support future studies of character evolution, hybridization, and species boundaries within the group.

The Texas Horned Lizard (Phrynosoma cornutum) has experienced significant habitat loss and population declines across their historic range in the southwestern United States; as such, the species has been listed as threatened by the Texas Parks and Wildlife Department. To mitigate declines, captive breeding programs have reintroduced large numbers of hatchlings into suitable habitat at the Mason Mountain Wildlife Management Area (MMWMA), which lies within the northern genetic cluster of Texas Horned Lizards. Long-term reintroduction success relies on the management of demographic factors and genetic variance. While demographic viability inherently increases with supplementation from an introduced population, the maintenance of genetic diversity within a reintroduced population must also be accounted for. If genetic management within captive breeding programs is not considered, the reintroduced population risks reduced allelic diversity and lower evolutionary potential, inbreeding depression, adaptation to captivity, or outbreeding depression if management units are mixed. We genotyped all captive-bred Texas Horned Lizards reintroduced in 2023 (N = 456 hatchlings) using 10 microsatellite loci to assess how genetically representative the introduced group is relative to natural populations. Measures of genetic diversity (uHe, He, Ho, AR) were calculated in GenAlEx, and full-sib groupings were constructed in COLONY. Results suggest that the differentiation between the captive and Northern populations is low (average Zoo population pairwise Fst: 0.014), and measures of genetic diversity were very similar (uHe, He, Ho, AR), indicating that the genetic diversity of the reintroduced hatchling population is representative of genetic diversity in North cluster populations. Linkage disequilibrium-based estimates of effective population size, however, reveal a small genetic effective population size (Ne = 37.2 - 44.6 individuals), which will quickly lead to a loss of genetic diversity. The small effective population size of a single reintroduced cohort and high post-release mortality rates underscore the need for continued annual supplementation to buffer against genetic drift, thereby promoting the long-term survival of managed Texas Horned Lizard populations.

Biaryl motifs are central in pharmaceutical drug design, yet conventional synthesis via palladium-catalyzed cross-coupling poses increasing sustainability and cost concerns. The study presented herein explores a greener alternative to palladium by employing iron(II) complexes supported by tetra-aza macrocyclic ligands for the direct arylation of pyrrole with phenylboronic acids. Under aerobic conditions, the optimized [Fe2+L1(Cl)2] catalyst featuring Me2Cyclam, (L1; 1,8-dimethyl-1,4,8,11-tetraazacyclotetradecane), exhibited broad substrate compatibility across 23 boronic acid derivatives. The method showed excellent functional group tolerance, including halides and esters, and provided yields up to 66%, which was clearly dependent on steric and electronic effects. Mechanistic experiments ruled out an outer-sphere radical pathway and instead suggested an Fe(III)–OOH species as the key oxidant, while DFT analysis supports enhanced boron electrophilicity for electron-withdrawing substituents, consistent with transmetalation as a central activation step. These findings highlight the potential of earth-abundant iron catalysts as sustainable, cost-effective platforms for C–C bond formation in complex molecular scaffolds.

Graphene quantum dots (GQDs) are emerging nanocarbon materials with tunable electronic structures and strong NIR emission, making them promising for bioimaging and optoelectronic applications. The chromophores responsible for GQDs’ NIR emission are often poorly characterized, limiting rational design and clinical applications. Extended π-conjugation, charge-transfer excitations, the presence of diradicaloids, stacking of multiple GQD layers, and blocking of nonradiative decay (as seen in non-aromatic fluorescence) may all contribute to GQDs’ NIR emission. Computation may help disentangle these contributions and aid development of NIR-emitting GQD nanostructures. However, predictive modeling of candidate GQD structures’ stability and NIR emission remains challenging. In this work, we develop a benchmark set of 16 well-defined GQD nanostructures known to emit in the NIR-I window, and we benchmark computational workflows for predicting these structures’ thermodynamic stability and NIR emission. Our workflows combine fast “pre-screening” of thermodynamic stability with symmetry-broken and symmetry-restricted time-dependent density functional theory (TD-DFT) predictions of absorption and emission, selected according to the open- or closed-shell nature of
each nanostructure. We find that B3LYP provides acceptable agreement with experimental absorption, while CAM-B3LYP shows good agreement with experimental emission, and that a “synthetic feasibility” descriptor provides reasonable initial screening. We believe that this workflow provides the foundation for high-throughput computational studies accelerating development of NIR-emitting GQDs.