Shallow water ecosystems such as small streams and lakes often exhibit abrupt thermal fluctuations, and fishes inhabiting these systems must cope with these challenging thermal regimes daily. Presently, both the rate of change of thermal thresholds including the Critical Thermal Maximum (CT_max) within hourly or daily timescales and the thermal performance of mitochondrial energy transduction after acclimation remains unexplored. The objective of this study was to evaluate the short-term response in CT_max of the green sunfish (Lepomis cyanellus) while acclimating to a 30°C thermal regime, along with assessing mitochondrial energy transduction efficiency after acclimation. Individuals were held at 20°C for 60 days, then subjected to a 10°C increase in acclimation temperature. CT_max were obtained after 24, 72, 96, 120 and 192h of acclimation. CT_max increased after 96 h of acclimation, from 35.6°C at 72h to 36.6°C at 96h, however the differences were not statistically significant (p = 0.059). Oxygen consumption associated to proton conductance across the inner membrane and phosphorylation rates were significantly higher in 20°C acclimated specimens, and the reaction norm of both rates were positively correlated to assay temperature. Interestingly, the mitochondrial energy transduction efficiency, calculated as the flux control efficiency ratio, decreased after warm acclimation. The present study shows a decreased respiratory capacity of L. cyanellus mitochondria exposed to summer temperatures. The latter effect likely impinges challenges to energetically expensive processes including somatic growth, locomotion, and reproductive behavior.

Glycoside hydrolases belonging to family 48 (GH48) are one of the most important cellulases responsible for the synergistic degradation of crystalline cellulose (CC) to glucose. Microbial DNA was extracted from soils and compost followed by PCR amplification to detect bacterial GH48 genes. Amplified fragments were cloned to develop DNA libraries to determine the diversity and community structure of bacterial genes responsible for cellulose degradation using GH48 genes. Soil bacterial communities were predominantly based upon unidentified GH48 genes (66%). When identification was possible, community composition analysis of soil samples showed 4 known bacterial phyla with Proteobacteria (23%), Actinobacteria (9%), Firmicutes (1%), and Bacteroidetes (1%). Phylogenetic analysis of unidentified clones showed 2% of clones clustered with a reference sequence from the Chloroflexota genus Herpetosiphon sp. Compost GH48 sequences were predominantly comprised of 3 different bacterial phyla belonging to Firmicutes (72%), Actinobacteria (16%), Myxococcota (5%) with 7% of sequences not matching any known bacteria. The most abundant microbial species in soil with GH48 genes was the Proteobacteria species Massilia violaceinigra (13%) while in compost the Firmicutes species Bacillus licheniformis showed the highest percentage (70%). Soil communities showed a higher genetic diversity than compost predominantly composed of unknown genetic sequences showing the potential to isolate and characterize new cellulases from soil. The contribution of different bacterial phyla, genera, and species to the synergistic CC degradation by GH48 genes demonstrated the importance of diverse bacterial communities to optimize carbon recycling in the environment.

Anxiety disorders are more prevalent in females than males, in part due to the change in ovarian hormones during the late luteal phase of the menstrual cycle. Estradiol and progesterone (E+P) peak in the luteal phase before dropping rapidly in the late luteal phase. This drop is associated with increased anxiety, and E+P may decrease anxiety. It is important to find a way to counteract the negative symptoms associated with ovarian hormone changes. Omega-3 fatty acid supplementation has been found to decrease anxiety-like behavior in male rats, but the effects on anxiety-like behavior in females are unknown. To determine the effect of omegas and E+P on anxiety-like behavior in female rats, we observed two trials of the elevated plus maze (EPM) and light-dark box after omega-3 fatty acid and E+P treatments. There was a decrease in time spent and crosses in the open arm of the EPM and the light side of the light-dark box across trials and no effect of omega-3 fatty acids or E+P. Further research into the potential interaction of omega-3 fatty acids and E+P is needed.

Honey bees are crucial to human survival in their role as generalist pollinators. However, humans also impact honey bees through the use of agricultural chemicals, typically aimed at increasing crop yield. Pesticide exposure to honey bees has been associated with a decrease in colony growth and fewer queens being born. However, the safety of pesticides is derived from acute feeding studies that focus on mortality. Pesticides are now ubiquitous in the environment and honey bees are constantly exposed. Studies utilizing long-term exposure better represent the lifetime experience of a typical honey bee. Here we measured changes in associative learning following 1 week of exposure to one of two sub-lethal, field-relevant doses of imidacloprid. While neither concentration of pesticide altered mortality relative to control, learning acquisition decreased in the high compared to control groups. These data demonstrate that chronic exposure to field-relevant doses of imidacloprid impact the ability for honey bees to form memories. The foraging success of honey bees relies on remembering the location of the hive and potential forage locations.

Extensive antibiotic use in the poultry industry has given rise to concerns of the proliferation and potential zoonotic transmission of antimicrobial-resistant pathogens. To mitigate the extent of antibiotic dosing, probiotics have been proposed as an alternate means of enhancing chick immune function by boosting host defense peptide (HDP) production. This study measured chick immune response to in ovo supplementation of a commercial poultry probiotic when subsequently exposed to a mimicked viral threat using polyinosinic-polycytidylic acid (poly(I:C)). To assess systemic immune responses to these conditions, real-time PCR was conducted to measure changes in expression of five immune-related genes in the spleen: TLR-3, AvBD-2, IFN-α, IFN-β, and IL-6. The chicks that received only the probiotic treatment saw a downregulation of TLR-3 (p=0.0013) and an upregulation of AvBD-2 (p=0.0105). The expression of IL-6 tended towards downregulation (p=0.06) with a potential interaction between the probiotic and poly(I:C) treatments (p=0.0794). Upregulation of AvBD-2 indicates a higher basal output of the chick's innate immune system upon early exposure to probiotics. These results suggest that enhanced systemic immune response in chicks can be achieved through early application of probiotics and is occurring through immunomodulation pathways that have not been fully elucidated.

Adult stem cells are necessary for the maintenance of many tissues, including the skin, blood, and intestinal lining. While most adult somatic cells have exited the cell cycle, adult stem cells maintain the ability to divide throughout an organism's lifetime. A recent study suggested that protein degradation may be important for cell cycle regulation in Drosophila intestinal stem cells. We hypothesized that two specific E3 ubiquitin ligase complexes, CRL4^Cdt2 and SCF^Skp2, might be required in Drosophila intestinal stem cells because both have been shown to mediate the destruction of the cell cycle inhibitor Dacapo (Dap). In this preliminary study, we used RNAi to knock down either Cdt2 or Skp2 to reduce the activity of either CRL4^Cdt2 or SCF^Skp2, respectively, in the adult intestine. Adult intestines with knockdown of either Cdt2 or Skp2 exhibited significant decreases in mitotic activity as well as changes in intestinal morphology. Our findings suggest that protein degradation mediated by both CRL4^Cdt2 and SCF^Skp2 is required for intestinal stem cell function and maintenance of the adult intestinal lining. Future experiments should explore specific proteins that accumulate following knockdown of Cdt2 or Skp2 and link protein accumulation to changes in stem cell function.

Colony collapse disorder (CCD) has caused widespread death of honeybees, but the exact causes are not understood. Many scientists agree that pathogenic threats most likely contribute to CCD. Due to the integral ecosystem role bees fulfill, it is important to understand how honeybees respond immunologically to different factors to better inform practices to combat CCD. Quantifying the immunological cost of two different beekeeping approaches allows us to better understand how beekeeping practices affect bees' susceptibility to CCD. Within colonies, a plastic frame foundation provides structural support for the creation of honeycomb. Production of beeswax is energetically costly for colonies to produce, possibly causing energetic stress that may affect the colony's ability to fight pathogens. Two colonies were maintained, one with an internal plastic foundation on their frames and one without. We collected bees from each colony and extracted their hemolymph to quantify both their basal and activated immunological protein levels. Protein levels were higher in bees from the no foundation colony. Prophenoloxidase (PPO) activity trended toward higher levels in the no foundation colony, although this was not statistically significant. This suggests that lack of foundation causes the bees to have a higher protein turnover based on their energetic requirements, increasing their ability to fight off immunological threats.

Successfully navigating daily life requires the ability to process and respond to information and make adaptive decisions. Decision-making behaviors can be studied in mice as they share many of the same core working memory and cognitive processes with humans. The pyControl open-source chamber was selected as an affordable, customizable device that would allow for the testing of a wide range of behaviors including working memory and decision-making. Here, a pilot study was conducted to test the functionality of this apparatus in an undergraduate research setting. Mice were given time to acclimate to the chamber while the research team created and troubleshot the task in Python. Training occurred so that mice would associate responses with sucrose water rewards. Finally, mice were trained on a delayed match-to-position task where the mice had to match their response with the same choice that they had made on a previous trial. The purpose of this pilot study was to build, code, and test the delayed match-to position task in the pyControl chamber. The success of this pilot study opens up a range of other applications for behavioral neuroscience and stands as a useful model for other undergraduate lab and classroom settings.

This review uses the total synthesis of vancomycin analogues by Boger and his colleagues as a case study of the drug discovery process. Vancomycin is a glycopeptide antibiotic used to treat staphylococcal infections. It acts by binding to the terminal chains attached to peptidoglycan in bacterial cell walls, which blocks these chains from crosslinking with each other. This inability to crosslink prevents the bacterium from forming a cell wall, ultimately resulting in bacterial cell death. However, over time, bacteria have evolved resistance to vancomycin. In response to this, Boger and his team studied single atom changes (O, S, NH) in the chemical structure of vancomycin to create new vancomycin analogues that these bacteria are not resistant to. The drug discovery process involves upstream and downstream flow of information about a potential drug candidate, and the interlude of Boger's work with vancomycin elegantly demonstrates this process. Boger found that replacing a single oxygen atom in vancomycin with NH significantly increases the ability of the analogue to bind with peptidoglycan terminal chains, increasing its effectiveness as an antibiotic.