The Effects of Sexual Dimorphism on Toxic Prey Avoidance in the Chinese Praying Mantis, Tenodera sinensis

This experiment strives to investigate if sex based behaviors in praying mantid feeding habits hold true when sexual dimorphism is not obvious in juvenile mantids Sensitivity to bitter tastes provides an important means for animals to detect various toxic compounds in food (Wooding et al.2006). In predators, taste sensitivity also allows animals to exploit nutritious but toxic food sources by monitoring the consumption of compounds that may cause illness or death (Wooding et al. 2006). Studies on the Chinese praying mantis, Tenodera sinensis, show that the mantids will wipe their mouths, shake, and reject bitter tasting toxic prey when it is encountered (Carle et al. 2015). Adult male mantids were found to have a more exaggerated response, lower level of acceptance, and reduced consumption of bitter prey compared to females who have higher nutritional requirements due to their larger bodies and reproductive cycles (Carle et al. 2015). A difference in juvenile mantid feeding behavior based on sex has not been observed (Paradise and Stamp, 1991)

Flux and Seasonality of Dissolved Organic Matter From the Northern Dvina (Severnaya Dvina) River, Russia

Pan‐Arctic riverine dissolved organic carbon (DOC) fluxes represent a major transfer of carbon from land‐to‐ocean, and past scaling estimates have been predominantly derived from the six major Arctic rivers. However, smaller watersheds are constrained to northern high‐latitude regions and, particularly with respect to the Eurasian Arctic, have received little attention. In this study, we evaluated the concentration of DOC and composition of dissolved organic matter (DOM) via optical parameters, biomarkers (lignin phenols), and ultrahigh resolution mass spectrometry in the Northern Dvina River (a midsized high‐latitude constrained river). Elevated DOC, lignin concentrations, and aromatic DOM indicators were observed throughout the year in comparison to the major Arctic rivers with seasonality exhibiting a clear spring freshet and also some years a secondary pulse in the autumn concurrent with the onset of freezing. Chromophoric DOM absorbance at a350 was strongly correlated to DOC and lignin across the hydrograph; however, the relationships did not fit previous models derived from the six major Arctic rivers. Updated DOC and lignin fluxes were derived for the pan‐Arctic watershed by scaling from the Northern Dvina resulting in increased DOC and lignin fluxes (50 Tg yr−1 and 216 Gg yr−1, respectively) compared to past estimates. This leads to a reduction in the residence time for terrestrial carbon in the Arctic Ocean (0.5 to 1.8 years). These findings suggest that constrained northern high‐latitude rivers are underrepresented in models of fluxes based from the six largest Arctic rivers with important ramifications for the export and fate of terrestrial carbon in the Arctic Ocean

Sex-Related Differences in Oxidant and Antioxidant Profiles of Murine Kidney and Brain: A Focus on Sirt3-Mediated Regulation

Background: Sirt3 is a mitochondrial deacetylase with an important role in maintainance of cellular redox and metabolic homeostasis and mitochondrial function. As growing evidence support the existence of sex-specific responses to metabolic and oxidative stress, we aimed to investigate sex- and organ-specific effects of Sirt3 loss. Materials and methods: Expression of Sirt3, PGC-1a, CuZnSOD, MnSOD and Cat proteins in kidneys and brains of Sirt3-wild type (Sirt3 WT) and Sirt3-knockout (Sirt3 KO) mice was assessed by Western blotting. Protein carbonylation and lipid peroxidation levels were measured using ELISA and fluorometric assays, respectively. SOD and Cat activities were determined using standard enzymatic assays. Results: Significant sex- and organ- specific differences in response to Sirt3 loss were detected. Sirt3 knockout affected kidneys more than brain tissue, with females showing lower levels PC and LPO. In kidneys, female KO showed higher MnSOD, but lower CuZnSOD and Cat activity compared to males. In brains, WT females show higher activities of these enzymes than males, suggesting a sex-specific protection mechanism, but female KO brains show a larger decrease in these parameters. Conclusion: Our study provides comprehensive insights into the complex interplay of Sirt3, oxidative stress, and antioxidant defenses in murine kidney and brain. The observed differences between the two organs and the impact of sex highlight the need for studying Sirt3 function in diverse physiological contexts. The tissue-specific responses and sex-related variations underscore the importance of considering these factors in the development of therapeutic strategies targeting mitochondrial function and redox homeostasis

Ancient Origins of Cytoskeletal Crosstalk: Spectraplakin-like Proteins Precede the Emergence of Cortical Microtubule Stabilization Complexes as Crosslinkers

Adhesion between cells and the extracellular matrix (ECM) is one of the prerequisites for multicellularity, motility, and tissue specialization. Focal adhesions (FAs) are defined as protein complexes that mediate signals from the ECM to major components of the cytoskeleton (microtubules, actin, and intermediate filaments), and their mutual communication determines a variety of cellular processes. In this study, human cytoskeletal crosstalk proteins were identified by comparing datasets with experimentally determined cytoskeletal proteins. The spectraplakin dystonin was the only protein found in all datasets. Other proteins (FAK, RAC1, septin 9, MISP, and ezrin) were detected at the intersections of FAs, microtubules, and actin cytoskeleton. Homology searches for human crosstalk proteins as queries were performed against a predefined dataset of proteomes. This analysis highlighted the importance of FA communication with the actin and microtubule cytoskeleton, as these crosstalk proteins exhibit the highest degree of evolutionary conservation. Finally, phylogenetic analyses elucidated the early evolutionary history of spectraplakins and cortical microtubule stabilization complexes (CMSCs) as model representatives of the human cytoskeletal crosstalk. While spectraplakins probably arose at the onset of opisthokont evolution, the crosstalk between FAs and microtubules is associated with the emergence of metazoans. The multiprotein complexes contributing to cytoskeletal crosstalk in animals gradually gained in complexity from the onset of metazoan evolution

Similarity solutions for unsteady shear-stress-driven flow of Newtonian and power-law fluids : slender rivulets and dry patches

Unsteady flow of a thin film of a Newtonian fluid or a non-Newtonian power-law fluid with power-law index N driven by a constant shear stress applied at the free surface, on a plane inclined at an angle α to the horizontal, is considered. Unsteady similarity solutions representing flow of slender rivulets and flow around slender dry patches are obtained. Specifically, solutions are obtained for converging sessile rivulets (0 < α < π/2) and converging dry patches in a pendent film (π/2 < α < π), as well as for diverging pendent rivulets and diverging dry patches in a sessile film. These solutions predict that at any time t, the rivulet and dry patch widen or narrow according to |x|3/2, and the film thickens or thins according to |x|, where x denotes distance down the plane, and that at any station x, the rivulet and dry patch widen or narrow like |t|−1, and the film thickens or thins like |t|−1, independent of N

Sirt3 Exerts Its Tumor-Suppressive Role by Increasing p53 and Attenuating Response to Estrogen in MCF-7 Cells

Estrogen (E2) is a major risk factor for the initiation and progression of malignancy in estrogen receptor (ER) positive breast cancers, whereas sirtuin 3 (Sirt3), a major mitochondrial NAD+-dependent deacetylase, has the inhibitory effect on the tumorigenic properties of ER positive MCF-7 breast cancer cells. Since it is unclear if this effect is mediated through the estrogen receptor alpha (ERα) signaling pathway, in this study, we aimed to determine if the tumor-suppressive function of Sirt3 in MCF-7 cells interferes with their response to E2. Although we found that Sirt3 improves the antioxidative response and mitochondrial fitness of the MCF-7 cells, it also increases DNA damage along with p53, AIF, and ERα expression. Moreover, Sirt3 desensitizes cells to the proliferative effect of E2, affects p53 by disruption of the ERα–p53 interaction, and decreases proliferation, colony formation, and migration of the cells. Our observations indicate that these tumor-suppressive effects of Sirt3 could be reversed by E2 treatment only to a limited extent which is not sufficient to recover the tumorigenic properties of the MCF-7 cells. This study provides new and interesting insights with respect to the functional role of Sirt3 in the E2-dependent breast cancers

Circumventing antivector immunity: potential use of nonhuman adenoviral vectors

Adenoviruses are efficient gene delivery vectors based on their ability to transduce a wide variety of cell types and drive high-level transient transgene expression. While there have been advances in modifying human adenoviral (HAdV) vectors to increase their safety profile, there are still pitfalls that need to be further addressed. Preexisting humoral and cellular immunity against common HAdV serotypes limits the efficacy of gene transfer and duration of transgene expression. As an alternative, nonhuman AdV (NHAdV) vectors can circumvent neutralizing antibodies against HAdVs in immunized mice and monkeys and in human sera, suggesting that NHAdV vectors could circumvent preexisting humoral immunity against HAdVs in a clinical setting. Consequently, there has been an increased interest in developing NHAdV vectors for gene delivery in humans. In this review, we outline the recent advances and limitations of HAdV vectors for gene therapy and describe examples of NHAdV vectors focusing on their immunogenicity, tropism, and potential as effective gene therapy vehicles

Tissue‐specific regulation of cytochrome c by post‐translational modifications: respiration, the mitochondrial membrane potential, ROS, and apoptosis

Cytochrome c (Cytc) plays a vital role in the mitochondrial electron transport chain (ETC). In addition, it is a key regulator of apoptosis. Cytc has multiple other functions including ROS production and scavenging, cardiolipin peroxidation, and mitochondrial protein import. Cytc is tightly regulated by allosteric mechanisms, tissue‐specific isoforms, and post‐translational modifications (PTMs). Distinct residues of Cytc are modified by PTMs, primarily phosphorylations, in a highly tissue‐specific manner. These modifications downregulate mitochondrial ETC flux and adjust the mitochondrial membrane potential (ΔΨm), to minimize reactive oxygen species (ROS) production under normal conditions. In pathologic and acute stress conditions, such as ischemia–reperfusion, phosphorylations are lost, leading to maximum ETC flux, ΔΨm hyperpolarization, excessive ROS generation, and the release of Cytc. It is also the dephosphorylated form of the protein that leads to maximum caspase activation. We discuss the complex regulation of Cytc and propose that it is a central regulatory step of the mammalian ETC that can be rate limiting in normal conditions. This regulation is important because it maintains optimal intermediate ΔΨm, limiting ROS generation. We examine the role of Cytc PTMs, including phosphorylation, acetylation, methylation, nitration, nitrosylation, and sulfoxidation and consider their potential biological significance by evaluating their stoichiometry.—Kalpage, H. A., Bazylianska, V., Recanati, M. A., Fite, A., Liu, J., Wan, J., Mantena, N., Malek, M. H., Podgorski, I., Heath, E. I., Vaishnav, A., Edwards, B. F., Grossman, L. I., Sanderson, T. H., Lee, I., Hüttemann, M. Tissue‐specific regulation of cytochrome c by post‐translational modifications: respiration, the mitochondrial membrane potential, ROS, and apoptosis. FASEB J. 33, 1540–1553 (2019). www.fasebj.orgPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154496/1/fsb2fj201801417r.pd