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1. Does Cellular Metabolism from Primary Fibroblasts and Oxidative Stress in Blood Differ between Mammals and Birds? The (Lack-thereof) Scaling of Oxidative Stress

   https://doi.org/10.1093/icb/icz017  

   Jimenez, A G ; O’Connor, E S ; Tobin, K J ; Anderson, K N ; Winward, J D ; Fleming, A ; Winner, C ; Chinchilli, E ; Maya, A ; Carlson, K ; et al ( April 2019 , Integrative and Comparative Biology)

   Abstract As part of mitonuclear communication, retrograde and anterograde signaling helps maintain homeostasis under basal conditions. Basal conditions, however, vary across phylogeny. At the cell-level, some mitonuclear retrograde responses can be quantified by measuring the constitutive components of oxidative stress, the balance between reactive oxygen species (ROS) and antioxidants. ROS are metabolic by-products produced by the mitochondria that can damage macromolecules by structurally altering proteins and inducing mutations in DNA, among other processes. To combat accumulating damage, organisms have evolved endogenous antioxidants and can consume exogenous antioxidants to sequester ROS before they cause cellular damage. ROS are also considered to be regulated through a retrograde signaling cascade from the mitochondria to the nucleus. These cellular pathways may have implications at the whole-animal level as well. For example, birds have higher basal metabolic rates, higher blood glucose concentration, and longer lifespans than similar sized mammals, however, the literature is divergent on whether oxidative stress is higher in birds compared with mammals. Herein, we collected literature values for whole-animal metabolism of birds and mammals. Then, we collected cellular metabolic rate data from primary fibroblast cells isolated from birds and mammals and we collected blood from a phylogenetically diverse group of birds andmore »mammals housed at zoos and measured several parameters of oxidative stress. Additionally, we reviewed the literature on basal-level oxidative stress parameters between mammals and birds. We found that mass-specific metabolic rates were higher in birds compared with mammals. Our laboratory results suggest that cellular basal metabolism, total antioxidant capacity, circulating lipid damage, and catalase activity were significantly lower in birds compared with mammals. We found no body-size correlation on cellular metabolism or oxidative stress. We also found that most oxidative stress parameters significantly correlate with increasing age in mammals, but not in birds; and that correlations with reported maximum lifespans show different results compared with correlations with known aged birds. Our literature review revealed that basal levels of oxidative stress measurements for birds were rare, which made it difficult to draw conclusions.« less
2. Metabolism and antioxidant defense in the larval chironomid Tanytarsus minutipalpus : Adjustments to diel variations in the extreme conditions of Lake Magadi

   https://doi.org/10.1242/bio.021139  

   Bianchini, Lucas F. ; Wood, Chris M. ; Bergman, Harold L. ; Johannsson, Ora E. ; Laurent, Pierre ; Chevalier, Claudine ; Kisipan, Mosiany L. ; Kavembe, Geraldine D. ; Papah, Michael B. ; Brix, Kevin V. ; et al ( January 2016 , Biology Open)

   Insect larvae are reported to be a major component of the simple but highly productive trophic web found in Lake Magadi (Kenya, Africa), which is considered to be one of the most extreme aquatic environments on Earth. Previous studies show that fish must display biochemical and physiological adjustments to thrive under the extreme conditions of the lake. However, information for invertebrates is lacking. In the present study, the occurrence of the larval chironomid Tanytarsus minutipalpus is reported in Lake Magadi for the first time. Additionally, changes in larval metabolism and antioxidant defense correlated with diel variations in the extremely hostile environmental conditions of the lake are described. Wide variations in water temperature (20.2-29.3oC) and dissolved oxygen content (3.2-18.6 mg O2 L−1) were observed at different times of day, without significant change in water pH (10.0±0.03). Temperature and dissolved oxygen were higher at 1:00 pm (29.3±0.4oC and 18.6±1.0 mg O2 L−1) and 7:00 pm (29.3±0.8oC and 16.2±1.6 mg O2 L−1) and lower at 1:00 am (21.1±0.1oC and 10.7±0.03 mg O2 L−1) and 7:00 am (20.2±0.4oC and 3.2±0.7 mg O2 L−1). Significant and parallel increases in parameters related to metabolism (cholinesterase, glucose, cholesterol, urea, creatinine and hemoglobin) and the antioxidant system (SOD,more »GPx, GR, GSH and GSSG) were observed in larvae collected at 1:00 pm. In contrast, no significant changes were observed in pro-oxidants (ROS and NO), TOSC and oxidative damage parameters (LPO and DNA damage). Therefore, the observed increases in temperature and dissolved O2 content in Lake Magadi were associated with changes in the antioxidant system of T. minutipalpus larvae. Adjustments performed by the chironomid larvae were efficient in maintaining body homeostasis, as well as protecting biomolecules against oxidative damage, so that oxidative stress did not occur. GSH-GSSG and GPx-GR systems appeared to play an essential role in the adjustments displayed by the chironomid larvae during the diel changes in the extreme conditions of Lake Magadi.

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3. Cellular metabolism and IL-6 concentrations during stimulated inflammation in small and large dog breeds’ primary fibroblasts cells, as they age

   https://doi.org/10.1242/jeb.233734  

   Jimenez, Ana Gabriela ; Downs, Cynthia J. ; Lalwani, Sahil ; Cipolli, William ( January 2021 , Journal of Experimental Biology)

   The immune system undergoes marked changes during aging characterized by a state of chronic, low-grade inflammation, so called inflammaging. Domestic dogs are the most morphological and physiological diverse group of mammals, with the widest range in body masses for a single species. Additionally, smaller dogs tend to live significantly longer than larger dogs across all breeds. Body mass is intricately linked to mass-specific metabolism and aging rates, thus, dogs are exemplary for studies in inflammaging. Dermal fibroblasts cells play an important role in skin inflammation, and as such, are a good cell type to determine inflammatory patterns in dogs. Here, we examine aerobic and glycolytic cellular metabolism, and IL-6 concentrations in primary fibroblast cells isolated from small and large, young and old dogs when treated with lipopolysaccharide (LPS) from Escherichia coli to stimulate an inflammatory phenotype. We found no differences in cellular metabolism of any group when treated with LPS. Unlike mice and humans, there was a less drastic amplification of IL-6 concentration after LPS treatment in the geriatric population of dogs compared with puppies. We also found evidence that large breed puppies have significantly less background or control IL-6 concentrations compared with small breed puppies. This implies that themore »patterns of inflammaging in dogs may be distinct and different from other mammals commonly studied.« less
4. Flight and Dietary Antioxidants Influence Antioxidant Expression and Activity in a Migratory Bird

   https://doi.org/10.1093/iob/obab035  

   DeMoranville, Kristen J. ; Carter, Wales A. ; Pierce, Barbara J. ; McWilliams, Scott R. ( December 2021 , Integrative Organismal Biology)

   Ecologically relevant factors such as exercise and diet quality can directly influence how physiological systems work including those involved in maintaining oxidative balance; however, to our knowledge, no studies to date have focused on how such factors directly affect expression of key components of the endogenous antioxidant system (i.e., transcription factors, select antioxidant genes, and corresponding antioxidant enzymes) in several metabolically active tissues of a migratory songbird. We conducted a three-factor experiment that tested the following hypotheses: (H1) Daily flying over several weeks increases the expression of transcription factors NRF2 and PPARs as well as endogenous antioxidant genes (i.e., CAT, SOD1, SOD2, GPX1, GPX4), and upregulates endogenous antioxidant enzyme activities (i.e., CAT, SOD, GPx). (H2) Songbirds fed diets composed of more 18:2n-6 PUFA are more susceptible to oxidative damage and thus upregulate their endogenous antioxidant system compared with when fed diets with less PUFA. (H3) Songbirds fed dietary anthocyanins gain additional antioxidant protection and thus upregulate their endogenous antioxidant system less compared with songbirds not fed anthocyanins. Flight training increased the expression of 3 of the 6 antioxidant genes and transcription factors measured in the liver, consistent with H1, but for only one gene (SOD2) in the pectoralis. Dietarymore »fat quality had no effect on antioxidant pathways (H2), whereas dietary anthocyanins increased the expression of select antioxidant enzymes in the pectoralis, but not in the liver (H3). These tissue-specific differences in response to flying and dietary antioxidants are likely explained by functional differences between tissues as well as fundamental differences in their turnover rates. The consumption of dietary antioxidants along with regular flying enables birds during migration to stimulate the expression of genes involved in antioxidant protection likely through increasing the transcriptional activity of NRF2 and PPARs, and thereby demonstrates for the first time that these relevant ecological factors affect the regulation of key antioxidant pathways in wild birds. What remains to be demonstrated is how the extent of these ecological factors (i.e., intensity or duration of flight, amounts of dietary antioxidants) influences the regulation of these antioxidant pathways and thus oxidative balance.

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5. The Australasian dingo archetype: de novo chromosome-length genome assembly, DNA methylome, and cranial morphology

   https://doi.org/10.1093/gigascience/giad018  

   Ballard, J William ; Field, Matt A ; Edwards, Richard J ; Wilson, Laura A ; Koungoulos, Loukas G ; Rosen, Benjamin D ; Chernoff, Barry ; Dudchenko, Olga ; Omer, Arina ; Keilwagen, Jens ; et al ( January 2023 , GigaScience)

   Abstract Background One difficulty in testing the hypothesis that the Australasian dingo is a functional intermediate between wild wolves and domesticated breed dogs is that there is no reference specimen. Here we link a high-quality de novo long-read chromosomal assembly with epigenetic footprints and morphology to describe the Alpine dingo female named Cooinda. It was critical to establish an Alpine dingo reference because this ecotype occurs throughout coastal eastern Australia where the first drawings and descriptions were completed. Findings We generated a high-quality chromosome-level reference genome assembly (Canfam_ADS) using a combination of Pacific Bioscience, Oxford Nanopore, 10X Genomics, Bionano, and Hi-C technologies. Compared to the previously published Desert dingo assembly, there are large structural rearrangements on chromosomes 11, 16, 25, and 26. Phylogenetic analyses of chromosomal data from Cooinda the Alpine dingo and 9 previously published de novo canine assemblies show dingoes are monophyletic and basal to domestic dogs. Network analyses show that the mitochondrial DNA genome clusters within the southeastern lineage, as expected for an Alpine dingo. Comparison of regulatory regions identified 2 differentially methylated regions within glucagon receptor GCGR and histone deacetylase HDAC4 genes that are unmethylated in the Alpine dingo genome but hypermethylated in the Desert dingo.more »Morphologic data, comprising geometric morphometric assessment of cranial morphology, place dingo Cooinda within population-level variation for Alpine dingoes. Magnetic resonance imaging of brain tissue shows she had a larger cranial capacity than a similar-sized domestic dog. Conclusions These combined data support the hypothesis that the dingo Cooinda fits the spectrum of genetic and morphologic characteristics typical of the Alpine ecotype. We propose that she be considered the archetype specimen for future research investigating the evolutionary history, morphology, physiology, and ecology of dingoes. The female has been taxidermically prepared and is now at the Australian Museum, Sydney.« less