Cold-water fishes, such as Brook trout (Salvelinus fontinalis), are being challenged by the consequences of climate change. The ability of these fish to acclimate to warmer environmental conditions is vital to their survival. Acclimation to warmer water may allow brook trout to reduce the metabolic costs of higher temperatures. Previous work has shown that brook trout display a significant thermal acclimation response in their myotomal muscle, with slower contractile properties observed in warm acclimated fish. In this study, gene expression was examined in hatchery brook trout acclimated to a range in temperatures (4, 10 or 20°C). Brook trout displayed variations in gene expression in their myotomal muscle in accordance with acclimation temperature. Genes important for muscle function, cellular metabolism, protein degradation, and stress response showed variation to both warm (20°C) and cold (4°C) acclimation. The warm acclimated fish also showed decreased expression of genes associated with aerobic metabolism and increased expression of genes for heat shock proteins, while the cold acclimated fish showed increased expression of genes associated with lipid metabolism and protein turnover. α-tubulin displayed a close association with thermal acclimation, increasing in expression with acclimation temperature. The patterns of muscle gene expression were the opposite of what was expected. Although warm acclimated fish have previously been shown to display slow muscle contractile properties, this study found that warm acclimation is associated with increased expression of genes for kinetically faster isoforms of important muscle proteins. Collectively, the results demonstrate a robust response to elevated temperature in the hatchery fish greater than 10,000 genes showing differential expression with temperature. These results provide a roadmap for the analysis of the acclimation response of native populations of brook trout encountering climate change.

Mice in the genus Peromyscus are abundant and geographically widespread in North America, serving as reservoirs for zoonotic pathogens, including Borrelia burgdorferi (B. burgdorferi), the causative agent of Lyme disease, transmitted by Ixodes scapularis ticks. While the white-footed mouse (Peromyscus leucopus (P. leucopus)) is the primary reservoir in the United States, the deer mouse (P. maniculatus), an ecologically similar congener, rarely transmits the pathogen to biting ticks. Understanding the factors that allow these similar species to serve as a poor and competent reservoir is critical for understanding tick-borne disease ecology and epidemiology, especially as climate change expands the habitats where ticks can transmit pathogens. Our study investigated immunological differences between these rodent species. Specifically, we compared the expression of six immune genes (i.e., TLR-2, IFN-γ, IL-6, IL-10, GATA-3, TGF-β) broadly involved in bacterial recognition, elimination, and/or pathology mitigation in ear biopsies collected by the National Ecological Observatory Network (NEON) as part of their routine surveillance. A principal components analysis indicated that immune gene expression in both species varied in two dimensions: TLR2, IFN-γ, IL-6, and IL-10 (comprising PC1) and TGF-β and GATA3 (comprising PC2) expression tended to covary within individuals. However, when we analyzed expression differences of each gene singly between species, P. maniculatus expressed more TLR2, IL-6, and IL-10 but less IFN-γ and GATA3 than P. leucopus. This immune profile could partly explain why P. leucopus is a better reservoir for bacterial pathogens such as B. burgdorferi.

Exposure of avian mothers to stressful conditions permanently alters offspring behavior and physiology. Yet, the effects of maternal stress on the development of offspring immunity in birds remain unclear, particularly in wild species. We injected Eastern bluebird (Sialia sialis) eggs with either a corticosterone or control solution, then measured the impacts on nestling morphology and two measures of immunity, bactericidal capacity and swelling responses to phytohemagglutinin. Nestlings from corticosterone-treated eggs had lower condition indices at hatch but quickly caught up to their control counterparts by Day 5 posthatch and until fledging. Corticosterone-exposed nestlings also mounted smaller swelling responses to phytohemagglutinin, whereas there were no effects on bactericidal capacity. These results indicate that maternal stress can impact offspring immunocompetence, fitness prospects, and potentially their ability to fend off parasites and pathogens.

An animal's body mass is said to be indirectly related to its rate of heat loss; that is, smaller animals with higher surface area to volume tend to lose heat faster than larger animals. Thus, thermoregulation should be related to body size, however, generalizable patterns are still unclear. Domestic dogs are a diverse species of endothermic mammals, including a 44-fold difference in body size. Previous work in sedentary dogs has determined that body size and other morphological variables tend to predict the thermoregulation of exercising pet dogs. Here, we aimed to address three questions: (1) whether thermoregulatory differences in domestic dogs across seasons are dictated strictly by external environmental temperatures or if individual thermal acclimation is affected by seasonal temperature variation, even indoors; (2) whether athleticism (or training experience) affects or changes thermoregulation in dogs, as it does in humans; and (3) whether thermoregulation in domestic dogs has a genetic basis. We obtained tympanic membrane (T) temperatures and thermal images to measure the rate of temperature change in the eyes, mouth, and nose of athletic dogs following an indoor agility trial. Additionally, we used image analysis to determine body morphology differences. We found body mass to play a strong role in thermoregulation in winter trials (T p = 0.017, T p = 0.052) but a less determinate role in summer trials. We found distinct differences in thermoregulation patterns between winter and summer. Particularly, coat morphology and length may play different roles in thermoregulation across seasons. Additionally, we found that rates of mouth temperature change differ by an interaction between environmental temperature and training experience (p = 0.044), suggesting seasonal thermoregulation patterns in dogs depend on relative athleticism. Lastly, we found important genetic predictors of temperature change rate, such as GORAB and IGF1, as well as others that exert influence over body size, mitochondrial function, or coat characteristics. These genetic markers indicate markers similar to our whole-animal physiological results. Overall, our data suggest that domestic dogs demonstrate thermal acclimation across seasons, that athleticism changes thermoregulatory patterns in domestic dogs, and that body size-related genes are associated with thermoregulation in dogs.

In the wild, stressors occur with varying likelihood throughout the day, leading animals to evolve plastic stress responses that exhibit circadian rhythmicity. In mammals, studies have revealed that the circadian plasticity of stress response may differ with age. However, such developmental effects have been largely overlooked in other vertebrate groups. In our research, we explored the presence of developmental variation in the daily pattern of behavioral stress response in a teleost fish model: the zebrafish (Danio rerio). We compared juvenile and adult individuals in two behavioral paradigms commonly used to analyze fish stress response, such as the open-field test and the diving test. Our comparisons were conducted every 4 h during a 24-h cycle to analyze daily variations. Significant daily rhythms were detected for almost all analyzed behaviors in both tests. In general, the analyses suggested a greater stress response in adults during the daytime and in juveniles during the night-time, although not all indicators aligned in this direction. Moreover, we found average differences in zebrafish behavior, suggesting that juveniles were more sensitive to stress. Overall, these findings highlight the importance of considering developmental variation in the circadian pattern of stress response in non-mammalian species like zebrafish.

To overcome infection, hosts employ two defense strategies: resistance (which limits pathogen fitness), and tolerance (which reduces infection damage). These strategies may be influenced by environmental challenges such as food shortage, social conflict, and co-infections. Here, our objective was to assess defense strategies in rats infected with Trichinella spiralis and/or Trypanosoma cruzi under environmental challenges. After four weeks of treatment with environmental challenges (food restriction [0/1] and/or social conflict [0/1]), rats were exposed to Tri. spiralis [0/1] and/or Try. cruzi [0/1]. Six weeks postinoculation, we measured parasite intensity and several indicators of health or pathology. Tolerance to Try. cruzi increased in the presence of social conflict and food restriction. Coinfected animals showed reduced tolerance compared to mono-infected. However, food-restricted mono-infected rats had lower tolerance than other groups. No significant differences were found in resistance to Try. cruzi. Tolerance to Tri. spiralis was higher in food-restricted rats and Coinfected rats. Moreover, we found a potential shift in defense strategy: rats that are mono-infected and exposed to social conflict may be more resistant but less tolerant to Tri. spiralis than all other experimental groups. Overall, our findings highlight that defense strategies are context-dependent in the nematode-protozoan infection model studied, and provide evidence of a shift in the defense strategy to accommodate during environmental challenges. Given that rodents play a key role as reservoirs of zoonotic pathogens, understanding the range and variability of defense strategies in these animals is of utmost importance.

Gastrointestinal infections present major challenges to ruminant livestock systems, and gut health is a key constraint on fitness, welfare, and productivity. Fecal biomarkers present opportunities to monitor animal health without using invasive methods, and with greater resolution compared to observational metrics. Here we developed enzyme-linked immunosorbent assays for three potential fecal biomarkers of gut health in domestic ruminants: two immunological (total immunoglobulin [Ig]A and total IgG) and one inflammatory (lactoferrin). We analytically validated the assays, then evaluated whether they could be used as a biomarker of clinically diagnosed gastrointestinal pathologies in cattle (Bos taurus), and finally compared them with helminth fecal egg counts in sheep (Ovis aries). The analytes were detected above the lower limits of detection in cattle, sheep, and goats. Fecal IgA and lactoferrin were higher in cattle with infectious pathologies (strongyles, coccidiosis and symptomatic Johne's disease) compared to healthy controls. Lactoferrin was additionally higher in animals with infectious pathologies compared to noninfectious pathologies, and to asymptomatic Johne's cases. No significant relationships were found with sheep fecal egg counts. These initial findings suggest that fecal IgA and lactoferrin may be useful biomarkers of poor gastrointestinal health in cattle, and that fecal lactoferrin is specific to active inflammation caused by infectious agents. These could be incorporated into the growing suite of noninvasive ecoimmunological tools and used to understand ruminant gut health in a range of species. Applications include improving treatment regimens for gastrointestinal infections, and understanding wildlife physiological responses to infectious challenges.

The open field test (OFT) is frequently used in research to assess anxiety-like behavior and locomotor activity. Its simple design can lead to the misconception that it is a standardized procedure comparable between laboratories. However, some modifications in the setup can cause changes in behavior. Different species might also react differently to the modifications introduced. There is thus need for a better understanding of the impact of modifications and their value for the species in question. Here, we tested two closely related mouse species, Mus musculus and Mus spretus, in an OFT with and without the presence of a shelter. We assessed mouse exploratory behavior through the analysis of multiple behavioral traits, and stress response through the measurement of circulating cortisol levels. Both species had elevated cortisol levels during the OFT in contrast to control animals which were not exposed to the OFT. While the presence of a shelter in the OFT increased the exploratory behavior in both mouse species, M. spretus, but not M. musculus, showed a reduction in cortisol levels. Also, other measured behaviors show a rather proactive coping strategy of the commensal M. musculus in contrast to a reactive strategy of the non-commensal M. spretus. Our study revealed a strong species-specific influence of the OFT design on the resulting behavior and stress levels of mice, illustrating the importance of OFT designs to account for the characteristics of the species under study. The addition of a shelter might be considered to improve experimental results by promoting animal welfare.

Noninvasive evaluations of hormones can contribute to the assessment of health and welfare of animals. Variations in insulin levels and sensitivity, for example, have been linked to health concerns in non-human and human primates including insulin resistance, diabetes, and heart disease, the leading cause of death in zoo-housed gorillas. Few published studies have assessed insulin concentrations in western lowland gorillas (Gorilla gorilla gorilla), and all did so using serum. Anesthesia is typically required to collect blood samples from zoo-housed gorillas, limiting sampling frequency and restricting samples to the fasted state. The ability to measure insulin levels in saliva would eliminate these constraints and provide a minimally invasive means for monitoring this hormone. The purpose of this study was to analytically and biologically validate the measurement of insulin in saliva of western lowland gorillas using a commercially available enzyme immunoassay. For validation, an oral sugar test was conducted on five adult gorillas residing at Cleveland Metroparks Zoo. Such assessments are common practice in both human and equine medicine to evaluate the body's insulin response to ingestion of sugars. The test involved measuring salivary insulin at timed intervals before and after gorillas consumed doses of sugar. Salivary insulin levels increased from 15 min post-sugar ingestion and peaked after 90 to 120 min. One female had a high response and peaked at 990.21 mU/L. The other four gorillas had peaks between 49.82 and 167.04 mU/L. The assessment provided a biological validation for the measurement of salivary insulin in western lowland gorillas.

Wound healing is a complex natural process in which tissue requires recovering injured tissue cells. Helix aspersa has a high nutritional value and is considered a rich natural source of antioxidants and anti-inflammatory agents. So, this study aimed to assess the effect of soft tissue crude extract and mucous of H. aspersa topically applied as a gel for 12 days. The wounds were observed and photographed twice a week. The inflammatory, oxidative stress markers and matrix metalloproteinases were evaluated in skin tissue homogenate and CD3 and CD69 T lymphocytes were detected in wound tissue. Data showed that a comparison of applying soft tissue crude extract and mucous of H. aspersa to skin wounds enhanced the healing process, resulting in a significant decrease in dermal inflammation compared to untreated mice. Also, they significantly increased the antioxidant enzyme activities with reduced malondialdehyde (MDA) levels in wound tissues. The levels of matrix metalloproteases-2 and -9 were significantly decreased and the immune status was enhanced in the wound environment by increasing proportions of CD3 and CD69 T lymphocytes. H. aspersa mucous and soft tissue crude extract are viable substitutes for synthetic topical wound therapies with anti-inflammatory, antioxidant, and immunomodulatory potencies, with a preference for the crude soft tissue extract based on the outcomes.

The Atlantic Forest broad-snouted caiman (Caiman latirostris) inhabits regions within one of the world's most ecologically diverse ecosystems, yet few studies have explored the relationship between body condition, blood biochemistry, and environmental factors in the wild. Our study investigated the effects of sex, ontogeny, habitat, and environmental variables on the body condition and blood biochemistry of free-ranging caimans from the state of Alagoas, Northeast Brazil. From 2020 to 2022, we captured 75 caimans across three sites in different seasons. Results revealed sex-specific responses to seasonal and Interannual weather changes, with females showing higher body condition in the wet season, while males peaked in the dry season. Elevated glucose, total protein, albumin, triglycerides, and fructosamine were linked to higher body condition and larger individuals, while elevated aspartate aminotransferase to low body condition. Seasonal rainfall influenced blood parameters, with the dry season associated with higher creatinine, calcium, and alanine aminotransferase levels, and the wet season with higher total protein, sodium, and potassium. Differences in glucose, alkaline phosphatase, and gamma-glutamyl transferase across sites pointed to physiological effects of human activities. Blood biochemical values varied widely, with some exceeding reported species ranges. These findings highlight the need to interpret physiological data within the context of local habitat and environmental conditions. Conservation strategies should go beyond species presence and habitat preservation, incorporating pollution control. Our study advances understanding of Caiman latirostris ecophysiology, offering valuable insights for the conservation and management of crocodilian populations in both wild and captive environments.

Artificial light sources, particularly blue light, have raised concerns about their impact on biological health and behavior. In this study, we explored the effects of blue light on the locomotion and cognitive functions of early adult Drosophila melanogaster. Our experiments were conducted in a custom-designed behavioral arena to assess how blue light influences these parameters. We found that after ~2 weeks of blue light exposure, the locomotion of fruit flies, including movement speed and activity levels, significantly increased, but these effects disappeared by the third week. However, this exposure also led to a notable reduction in lifespan and had adverse effects on cognitive functions, including attention and short-term spatial memory. These findings may reveal the profound impacts of blue light on neural behavioral functions and lifespan, highlighting the importance of further research into the biological effects of blue light.

Seasonally breeding animals undergo physiological and behavioral changes to time reproduction to occur during specific seasons. These changes are regulated by changing environmental conditions, which may be communicated to the brain using the central circadian clock. This clock consists of a daily oscillation in the expression of several core genes, including period (per), cryptochrome (cry), circadian locomotor output cycles kaput (clock), and basic helix-loop-helix ARNT-like protein 1 (bmal1). We began to examine seasonal regulation of four core circadian clock genes in a dissection of the reptile brain containing the hypothalamus-per1, cry1, bmal1 and clock. Our study focused on examining mRNA expression in the morning and compared levels between breeding and nonbreeding animals. We found that per1 and bmal1 mRNA expression was highest in the nonbreeding compared to breeding season in the anole hypothalamus. We also found that cry1 mRNA expression was higher in the female compared to the male anole hypothalamus. We found support for the idea that core circadian genes play a role in regulating changes between the seasons and/or sexes, although more work is needed to elucidate what processes might be differentially regulated. To our knowledge, this is the first examination of the expression of these four genes in the reptilian brain.

Pikeperch (Sander Lucioperca) belongs to main predatory fish species in freshwater bodies throughout Europe playing the key role by reducing planktivorous fish abundance. Two size classes of the young-of-the-year (YOY) pikeperch are known in Europe and North America. Our long-term fish survey elucidates late-summer size distribution of YOY pikeperch in the Lipno Reservoir (Czechia) and recognizes two distinct subcohorts: smaller pelagic planktivores heavily outnumber larger demersal piscivores. To explore molecular mechanisms accompanying the switch from planktivory to piscivory, we compared brain transcriptomes of both subcohorts and identified 148 differentially transcribed genes. The pathway enrichment analyses identified the piscivorous phase to be associated with genes involved in collagen and extracellular matrix generation with numerous Gene Ontology (GO), while the planktivorous phase was associated with genes for non-muscle-myosins (NMM) with less GO terms. Transcripts further upregulated in planktivores from the periphery of the NMM network were Pmchl, Pomcl, and Pyyb, all involved also in appetite control and producing (an)orexigenic neuropeptides. Noncoding RNAs were upregulated in transcriptomes of planktivores including three transcripts of snoRNA U85. Thirty genes mostly functionally unrelated to those differentially transcribed were alternatively spliced between the subcohorts. Our results indicate planktivores as potentially driven by voracity to initiate the switch to piscivory, while piscivores undergo a dynamic brain development. We propose a spatiotemporal spreading of juvenile development over a longer period and larger spatial scales through developmental plasticity as an adaptation to exploiting all types of resources and decreasing the intraspecific competition.

Maintaining stable hydric and thermal states are dual challenges for reptiles that inhabit terrestrial environments with variable conditions across time and space. Under some conditions, reptiles face a conundrum where both physiological parameters cannot be simultaneously maintained at preferred levels by behavioral or physiological means. Prioritization of behavioral regulation of hydric or thermal state, and at which point this prioritization changes, was tested for nine species of congeneric tropical geckos by assessing their use of microhabitats with distinct thermal and hydric conditions in a controlled environment. Gehyra geckos were presented with two crevices of contrasting humidity levels, and time spent in either crevice was recorded across three ambient temperature treatments of 32°C, 27°C, and 22°C. Temperatures in the humid crevice matched ambient air temperature, whereas temperature in the dry crevice was maintained at 32°C. In these trials, all species showed greater use of the dry (and warm) crevice in the 27°C and 22°C treatments, while there was no strong preference for the humid or dry crevice in the 32°C treatment. Thus, Gehyra geckos prioritized thermoregulation and maintained thermal state through behavioral responses, and humid microhabitats were not selected even when it did not compromise the animal's thermal state. Although selection for preferred thermal conditions was prioritized in the short term, this does not preclude the possibility that hydric state can be regulated on a seasonal time scale.

Comparative studies of reproductive biology and formation of reproductive isolation need appropriate model systems, such as groups of related species. The amphipods (Crustacea: Amphipoda) of ancient Lake Baikal are an attractive group for such works, as they consist of several hundred species that radiated within the lake and have very different levels of intraspecific genetic diversity and reproduction timing. We have previously shown that one of the most widely distributed and best studied littoral species, Eulimnogammarus verrucosus (Gersfeldt, 1858), comprises cryptic species exhibiting a post-zygotic reproductive barrier. The object of this study was Eulimnogammarus cyaneus (Dybowsky, 1874), another widespread endemic littoral Baikal species, which has a surprisingly low genetic diversity within its large geographic range. The aim of this study was to check if the populations isolated by the Angara River source, which is approximately 120-thousand years old, are reproductively compatible. As neither prezygotic nor postzygotic barriers were found, at the moment these populations should be treated as belonging to a single species. At the same time, we found some noteworthy features of reproduction of E. cyaneus. They include successive reproductive cycles with amplexuses formed by females with juveniles in the brood pouch and deposition of unfertilized eggs by females. The former might mean that this species is a relatively promising object for a laboratory culture of Baikal amphipods. Taken together, these results contribute to the establishment of a research framework to look for the correlation between genetic divergence and biological species delimitation.

Many songbirds begin active incubation after laying their penultimate egg, resulting in synchronous hatching of the clutch except for a last-hatched individual ("runt") that hatches with a size deficit and competitive disadvantage to siblings when begging for food. However, climate change may elevate temperatures and cause environmental incubation as eggs are laid, resulting in asynchronous hatching and larger size hierarchies among siblings. Although previous work demonstrated that asynchronous hatching reduces nestling growth and survival relative to synchrony, the physiological mechanisms underlying these effects are unclear. To test the effects of asynchronous hatching on runt growth, survival, physiology, and compensatory growth-related tradeoffs, we manipulated incubation temperature in nest boxes of European starlings (Sturnus vulgaris) to increase asynchronous hatching and collected nestling morphological measurements and blood samples to assess physiology and development. Independent of heating treatment, runts from asynchronously hatched nests had lower survival than runts from more synchronous nests. Surviving runts from asynchronous nests were smaller and had reduced stress-induced corticosterone concentrations and reduced circulating glucose compared with runts from synchronous nests. Despite persistent size and energy deficits, runts from asynchronous nests did not have significant deficits in immunity or telomere length when compared with runts from synchronous nests, suggesting no trade-off between investment in immune development or telomere maintenance with growth. Overall, these results suggest that increased asynchrony due to climate change could reduce clutch survival for altricial songbirds, especially for the smallest chicks in a clutch, and that the negative effects of asynchrony may be driven by persistent energetic deficits.

Estuaries are diverse coastal ecosystems that act as transitional zones between freshwater and seawater. The Don Hoi Lot tidal flat, located in the upper Gulf of Thailand, is one of Thailand's most important estuarine ecosystems. Nonetheless, the Don Hoi Lot area faces increasing environmental pressures due to human activities and natural changes. One of the most prominent species well-known in this area is the razor clam Solen regularis. This study investigated the effects of salinity fluctuations on the osmotic properties and antioxidant enzyme activities of the five tissues: foot, mantle, adductor muscle, gill, and digestive gland from the razor clam S. regularis collected from the Don Hoi Lot tidal flat. Razor clams were exposed to a range of salinity levels (0-35 PSU) for 7 days. The results indicated that the hemolymph osmolality of S. regularis increased with increasing salinity, demonstrating an osmoconforming pattern. Salinity changes significantly affected the activities of antioxidant enzymes (SOD, CAT, and GPX) in various tissues. In most tissues, SOD and CAT activities increased at higher salinities (30-35 PSU), while GPX activity generally increased across all tissues with increasing salinity. GST activity was not significantly affected by salinity changes. These findings suggest that S. regularis can activate antioxidant defense systems to reduce oxidative stress caused by salinity fluctuations. This study provides valuable insights into the physiological responses of S. regularis to environmental salinity changes, which can inform conservation efforts for this ecologically important species in estuarine ecosystems.

Food availability shapes morphology, physiology, growth, reproduction, and overall fitness of insects. Countless research in coccinellids reported the effect of diet in terms of quality and quantity on reproductive output. But fewer studies have reported the direct effects of food on the gonadal development in both sexes. In nature, ladybird beetle Cheilomenes sexmaculata exhibit food preference, favouring Aphis craccivora (nutritious prey) over Aphis nerii (poor prey). We hypothesized that beetles consuming nutritious prey in abundant quantity will have larger and heavier gonads. The current study assessed the effect of food preferred and its fluctuations on the gonadal development of C. sexmaculata. First instars were collected randomly from experimental stock and reared on two different diet regimes for a lifetime. After eclosion, beetles from each dietary regime were dissected daily to assess gonadal development until maturity. Here, we documented total developmental duration, body weight, weight of gonads, GSI, total area of gonads, length, and number of testicular lobules/ovarioles across different treatments. Both quality and quantity of diet significantly affected development period, body weight, and gonadal parameters in both sexes except for GSI in males and number of ovarioles in females that reared on varied diet quality, which were found to be similar. Aphis craccivora in abundant supply positively affected the growth and development of the gonads in C. sexmaculata. Beetles reared on the abundant supply of nutritious prey with larger and heavier gonads than those reared on limited supply or poor prey. This study improves our understanding of the development of gonads in ladybird beetles, which may be helpful in improving the mass rearing of ladybird beetles.

In euryhaline teleosts, the cystic fibrosis transmembrane conductance regulator (CFTR) in seawater (SW)-type chloride cells facilitates apical Cl secretion for SW adaptation, while alternative Cl excretion pathways remain understudied. This study investigates the role of the calcium-activated chloride channel, Anoctamin 1 (ANO1), in the gills of the euryhaline Japanese medaka (Oryzias latipes) under hyperosmolality and cortisol (CORT) influence. Acclimation to artificial SW, NaCl, mannitol, or glucose significantly upregulated ANO1 and CFTR mRNA expression in gills, unlike urea treatment. In situ hybridization revealed ANO1 mRNA in chloride cells co-expressing CFTR and Na, K-ATPase under hyperosmotic conditions. ANO1 inhibition elevated plasma Cl concentration, indicating impaired Cl excretion. CORT or dexamethasone administration in freshwater (FW) fish significantly increased branchial ANO1 and CFTR mRNA expression, an effect attenuated by the glucocorticoid receptor (GR) antagonist RU486. Hyperosmotic treatment of isolated gill tissues rapidly induced ANO1 mRNA expression independent of CFTR mRNA changes, and this induction was unaffected by RU486. These findings highlight the dual regulation of ANO1 expression via hyperosmolality-induced cellular response and the CORT-GR system. Thus, branchial ANO1 may likely complement CFTR in Cl⁻ excretion, playing a key role in the hyperosmotic adaptation of euryhaline teleosts.

One neglected zoonotic illness is toxocariasis. There are not enough anthelmintic drugs in the market to treat low-effectiveness toxocariasis against migrating larvae. Therefore, it is critical to find new, safe alternatives to toxocariasis treatment today. The venom of the Leiurus quinquestratus scorpion (LQV) has numerous medicinal uses. The purpose of this study was to conduct that LQV had an effect on T. canis larvae in the model of mice. Fifty male mice were divided into five groups (n = 10). Group 1 (Gp1) was the negative group, and from Gp2-Gp5 had been infected with 800-1000 T. canis embryonated eggs. Gp2 was left as positive control, Gp3 was orally administrated with albendazole (Alb) (100 mg/kg/b.wt) for 7 consecutive days at first day post infection (pi), Gp4 was injected intra-peritoneal (i.p) with LQV (0.03 mg/kg/b.wt) for 15 consecutive days at the first day pi, and Gp5 was given Alb/LQV in the same way and doses as Gp3 and Gp4. At the end of the experiment, at 30th pi, the blood samples were collected for evaluating the biochemical and hematological parameters. The larval count reduction in brain were evaluated, and the histopathological changes in brain and liver were detected. The results showed that, treatment with LQV or Alb/LQV combinations significantly reduced the larval burden in the brain of the infected mice with reduction percentage reached to 70, and 72%, respectively. Interestingly, LQV and Alb/LQV significantly reduced IL-4, IL-10, and TNF -α levels and increased IFN-γ levels. Also, improved the liver transaminases activity, and ameliorated liver and brain architecture. Collectively, LQV may be a promising treatment for T. canis infection and albendazole alternative.