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1.
BMC Biol ; 22(1): 91, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654271

RESUMO

BACKGROUND: Elephant seals exhibit extreme hypoxemic tolerance derived from repetitive hypoxia/reoxygenation episodes they experience during diving bouts. Real-time assessment of the molecular changes underlying protection against hypoxic injury in seals remains restricted by their at-sea inaccessibility. Hence, we developed a proliferative arterial endothelial cell culture model from elephant seals and used RNA-seq, functional assays, and confocal microscopy to assess the molecular response to prolonged hypoxia. RESULTS: Seal and human endothelial cells exposed to 1% O2 for up to 6 h respond differently to acute and prolonged hypoxia. Seal cells decouple stabilization of the hypoxia-sensitive transcriptional regulator HIF-1α from angiogenic signaling. Rapid upregulation of genes involved in glutathione (GSH) metabolism supports the maintenance of GSH pools, and intracellular succinate increases in seal but not human cells. High maximal and spare respiratory capacity in seal cells after hypoxia exposure occurs in concert with increasing mitochondrial branch length and independent from major changes in extracellular acidification rate, suggesting that seal cells recover oxidative metabolism without significant glycolytic dependency after hypoxia exposure. CONCLUSIONS: We found that the glutathione antioxidant system is upregulated in seal endothelial cells during hypoxia, while this system remains static in comparable human cells. Furthermore, we found that in contrast to human cells, hypoxia exposure rapidly activates HIF-1 in seal cells, but this response is decoupled from the canonical angiogenesis pathway. These results highlight the unique mechanisms that confer extraordinary tolerance to limited oxygen availability in a champion diving mammal.


Assuntos
Antioxidantes , Células Endoteliais , Focas Verdadeiras , Transdução de Sinais , Regulação para Cima , Animais , Focas Verdadeiras/fisiologia , Focas Verdadeiras/metabolismo , Células Endoteliais/metabolismo , Células Endoteliais/efeitos dos fármacos , Antioxidantes/metabolismo , Humanos , Hipóxia/metabolismo , Hipóxia Celular , Neovascularização Fisiológica/efeitos dos fármacos , Neovascularização Fisiológica/fisiologia , Células Cultivadas , Glutationa/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética
2.
J Neurosci Methods ; : 110139, 2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38626852

RESUMO

BACKGROUND: The brain is built of neurons supported by myelin, a fatty substance that improves cellular communication. Noninvasive magnetic resonance imaging (MRI) is now able to measure brain structure like myelin and requires histological validation. NEW METHOD: Here we present work in small and large biomedical model mammals to standardize a silver impregnation method as a high-throughput histological myelin visualization procedure. Specifically, we built a new staining well plate to increase batch size, and then systematically varied the staining and clearing cycles to describe the staining response curve across taxa and conditions. We compared tissues fixed by immersion or perfusion, mounted versus free-floating, and cut as thicker or thinner slices, with two-weeks of post-fixation. RESULTS: The staining response curves show optimal staining with a single exposure across taxa when incubation and clearing epochs are held to within 3 to 9minutes. We show that clearing was slower in mounted vs free-floating tissue, and that staining was faster and caused fracturing earlier in thinner sliced and smaller volumes of tissue. COMPARISON WITH EXISTING METHODS: We developed a batch processing approach to increase throughput while ensuring reproducibility and demonstrate the optimal conditions for fine myelinated fiber morphology visualization with short cycles (<9minutes). CONCLUSIONS: We present our optimized protocol to reveal mesoscale neuroanatomical myelin content in histology across mammals. This standard staining procedure will facilitate multiscale analyses of myelin content across development as well as in the presence of injury or disease.

3.
Folia Parasitol (Praha) ; 712024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38567406

RESUMO

Morphological data are used to describe a new nematode species, Heterocheilus floridensis sp. n. (Heterocheilidae) from the digestive tract of the Florida manatee Trichechus manatus latirostris (Harlan) (Trichechidae, Sirenia) from Florida, USA. Examination by light and scanning electron microscopy revealed that the new species differs from the related Heterocheilus tunicatus Diesing, 1839 mainly by having dentigerous ridges on the inner surface of the lips, a median unpaired papilla located anterior to the cloaca, and a considerably larger body size. Sequence data for subunits I and II of mitochondrial cytochrome oxidase gene, 18S small subunit and 28S ribosomal RNA genes were provided for molecular characterisation of the new species. However, the current unavailability of homologous sequence data for congeneric specimens precluded a molecular assessment of the morphological species hypothesis, and ascaridoid phylogenetic hypotheses could not be advanced. Specimens of Heterocheilus sp. collected from the Antillean manatee Trichechus manatus manatus Linnaeus in Puerto Rico, on loan from the US National Museum of Natural History, were morphologically consistent with the new species, so apparently all congeneric nematodes reported from both subspecies of the West Indian manatee Trichechus manatus Linnaeus and previously identified as H. tunicatus belong rather to H. floridensis sp. n. Heterocheilus hagenbecki (Khalil et Vogelsang, 1932) Sprent 1980 is here considered to be a species inquirenda. A key to valid species of Heterocheilus Diesing, 1839 is provided.


Assuntos
Nematoides , Trichechus manatus , Animais , Sirênios , Filogenia
4.
FEMS Microbiol Ecol ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658192

RESUMO

Gut bacterial communities play a vital role in a host's digestion, fermentation of complex carbohydrates, absorption of nutrients and energy harvest/storage. Dugongs are obligate seagrass grazers with an expanded hindgut and associated microbiome. Here, we characterised and compared the faecal bacterial communities of dugongs from genetically distinct populations along the east coast of Australia, between subtropical Moreton Bay and tropical Cleveland Bay. Amplicon sequencing of fresh dugong faecal samples (n=47) revealed Firmicutes (62%) dominating the faecal bacterial communities across all populations. Several bacterial genera (Bacteroides, Clostridium sensu stricto 1, Blautia and Polaribacter) were detected in samples from all locations, suggesting their importance in seagrass digestion. Principal coordinate analysis showed the three southern-most dugong populations having different faecal bacterial community compositions from northern populations. The relative abundances of the genera Clostridium sensu stricto 13 and dgA-11 gut group were higher, but Bacteroides was lower, in the southern dugong populations, compared to the northern populations, suggesting potential adaptive changes associated with location. This study contributes to our knowledge of the faecal bacterial communities of dugongs inhabiting Australian coastal waters. Future studies of diet selection in relation to seagrass availability throughout the dugong's range will help to advance our understanding of the roles that seagrass species may play in affecting the dugong's faecal bacterial community composition.

5.
Ecology ; : e4299, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38650359

RESUMO

Information on tropical Asian vertebrates has traditionally been sparse, particularly when it comes to cryptic species inhabiting the dense forests of the region. Vertebrate populations are declining globally due to land-use change and hunting, the latter frequently referred as "defaunation." This is especially true in tropical Asia where there is extensive land-use change and high human densities. Robust monitoring requires that large volumes of vertebrate population data be made available for use by the scientific and applied communities. Camera traps have emerged as an effective, non-invasive, widespread, and common approach to surveying vertebrates in their natural habitats. However, camera-derived datasets remain scattered across a wide array of sources, including published scientific literature, gray literature, and unpublished works, making it challenging for researchers to harness the full potential of cameras for ecology, conservation, and management. In response, we collated and standardized observations from 239 camera trap studies conducted in tropical Asia. There were 278,260 independent records of 371 distinct species, comprising 232 mammals, 132 birds, and seven reptiles. The total trapping effort accumulated in this data paper consisted of 876,606 trap nights, distributed among Indonesia, Singapore, Malaysia, Bhutan, Thailand, Myanmar, Cambodia, Laos, Vietnam, Nepal, and far eastern India. The relatively standardized deployment methods in the region provide a consistent, reliable, and rich count data set relative to other large-scale pressence-only data sets, such as the Global Biodiversity Information Facility (GBIF) or citizen science repositories (e.g., iNaturalist), and is thus most similar to eBird. To facilitate the use of these data, we also provide mammalian species trait information and 13 environmental covariates calculated at three spatial scales around the camera survey centroids (within 10-, 20-, and 30-km buffers). We will update the dataset to include broader coverage of temperate Asia and add newer surveys and covariates as they become available. This dataset unlocks immense opportunities for single-species ecological or conservation studies as well as applied ecology, community ecology, and macroecology investigations. The data are fully available to the public for utilization and research. Please cite this data paper when utilizing the data.

6.
Proc Biol Sci ; 291(2021): 20232681, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38654643

RESUMO

Early-life adversity, even when transient, can have lasting effects on individual phenotypes and reduce lifespan across species. If these effects can be mitigated by a high-quality later-life environment, then differences in future resources may explain variable resilience to early-life adversity. Using data from over 1000 wild North American red squirrels, we tested the hypothesis that the costs of early-life adversity for adult lifespan could be offset by later-life food abundance. We identified six adversities that reduced juvenile survival in the first year of life, though only one-birth date-had continued independent effects on adult lifespan. We then built a weighted early-life adversity (wELA) index integrating the sum of adversities and their effect sizes. Greater weighted early-life adversity predicted shorter adult lifespans in males and females, but a naturally occurring food boom in the second year of life ameliorated this effect. Experimental food supplementation did not replicate this pattern, despite increasing lifespan, indicating that the buffering effect of a future food boom may hinge on more than an increase in available calories. Our results suggest a non-deterministic role of early-life conditions for later-life phenotype, highlighting the importance of evaluating the consequences of early-life adversity in the context of an animal's entire life course.


Assuntos
Longevidade , Sciuridae , Animais , Masculino , Feminino , Sciuridae/fisiologia
7.
Genesis ; 62(2): e23597, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38590121

RESUMO

Sensory signals detected by olfactory sensory organs are critical regulators of animal behavior. An accessory olfactory organ, the vomeronasal organ, detects cues from other animals and plays a pivotal role in intra- and inter-species interactions in mice. However, how ethologically relevant cues control mouse behavior through approximately 350 vomeronasal sensory receptor proteins largely remains elusive. The type 2 vomeronasal receptor-A4 (V2R-A4) subfamily members have been repeatedly detected from vomeronasal sensory neurons responsive to predator cues, suggesting a potential role of this receptor subfamily as a sensor for predators. This review focuses on this intriguing subfamily, delving into its receptor functions and genetic characteristics.


Assuntos
Bulbo Olfatório , Órgão Vomeronasal , Camundongos , Animais , Bulbo Olfatório/fisiologia , Células Receptoras Sensoriais/metabolismo , Órgão Vomeronasal/metabolismo
8.
AJOG Glob Rep ; 4(1): 100321, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38586611

RESUMO

Preeclampsia is a syndrome with multiple etiologies. The diagnosis can be made without proteinuria in the presence of dysfunction of at least 1 organ associated with hypertension. The common pathophysiological pathway includes endothelial cell activation, intravascular inflammation, and syncytiotrophoblast stress. There is evidence to support, among others, immunologic causes of preeclampsia. Unlike defense immunology, reproductive immunology is not based on immunologic recognition systems of self/non-self and missing-self but on immunotolerance and maternal-fetal cellular interactions. The main mechanisms of immune escape from fetal to maternal immunity at the maternal-fetal interface are a reduction in the expression of major histocompatibility complex molecules by trophoblast cells, the presence of complement regulators, increased production of indoleamine 2,3-dioxygenase, activation of regulatory T cells, and an increase in immune checkpoints. These immune protections are more similar to the immune responses observed in tumor biology than in allograft biology. The role of immune and nonimmune decidual cells is critical for the regulation of trophoblast invasion and vascular remodeling of the uterine spiral arteries. Regulatory T cells have been found to play an important role in suppressing the effectiveness of other T cells and contributing to local immunotolerance. Decidual natural killer cells have a cytokine profile that is favored by the presence of HLA-G and HLA-E and contributes to vascular remodeling. Studies on the evolution of mammals show that HLA-E, HLA-G, and HLA-C1/C2, which are expressed by trophoblasts and their cognate receptors on decidual natural killer cells, are necessary for the development of a hemochorial placenta with vascular remodeling. The activation or inhibition of decidual natural killer cells depends on the different possible combinations between killer cell immunoglobulin-like receptors, expressed by uterine natural killer cells, and the HLA-C1/C2 antigens, expressed by trophoblasts. Polarization of decidual macrophages in phenotype 2 and decidualization of stromal cells are also essential for high-quality vascular remodeling. Knowledge of the various immunologic mechanisms required for adequate vascular remodeling and their dysfunction in case of preeclampsia opens new avenues of research to identify novel biological markers or therapeutic targets to predict or prevent the onset of preeclampsia.

9.
Ambio ; 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600245

RESUMO

Protected areas are a key component of global conservation, and the world is aiming to increase protected areas to cover 30% of land and water through the 30 × 30 Initiative under the Post-2020 Global Biodiversity Framework. However, factors affecting their success or failure in regard to promoting mammal population recovery are not well studied, particularly using quantitative approaches comparing across diverse taxa, biomes, and countries. To better understand how protected areas contribute to mammalian recovery, we conducted an analysis of 2706 mammal populations both inside and outside of protected areas worldwide. We calculated the annual percent change of mammal populations within and outside of terrestrial protected areas and examined the relationship between the percent change and a suite of human and natural characteristics including biome, region, International Union for Conservation of Nature (IUCN) protected area category, IUCN Red List classification, and taxonomic order. Our results show that overall mammal populations inside and outside of protected areas are relatively stable. It appears that Threatened mammals are doing better inside of protected areas than outside, whereas the opposite is true for species of least concern and Near Threatened species. We also found significant population increases in protected areas classified as category III and significant population decreases in protected and unprotected areas throughout Oceania. Our results demonstrate that terrestrial protected areas can be an important approach for mammalian recovery and conservation.

10.
PeerJ ; 12: e17244, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38590704

RESUMO

Nocturnal activity of tropical otters is rarely reported. To date no studies have documented den use by sympatric giant (Pteronura brasiliensis) and neotropical otters (Lontra longicaudis). We used camera-traps to monitor den use by sympatric otters along an equatorial Amazonian river. Camera-traps provided evidence that giant otters were more nocturnal around dens than sympatric neotropical otters. Nocturnal activity was recorded in 11% of giant otter photos (n = 14 of 125 photos), but was recorded only once for neotropical otters. Den use by giant and neotropical otters overlapped spatially and temporally but not concurrently. We hypothesize that previously reported nocturnal activity in neotropical otters is facilitated by the absence or low density of giant otters. Our results also underscore the need to use complementary techniques together with den counts for monitoring otters as sympatric species can use the same dens.


Assuntos
Carnívoros , Lontras , Animais , Simpatria , Rios
11.
Pest Manag Sci ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38624075

RESUMO

BACKGROUND: A major impact of the invasive Myocastor coypus in the introduction range is the collapse of riverbanks and nearby infrastructure, such as railway lines, due to the species' burrowing activities. As the ubiquitous implementation of preventive measures along watercourses is unfeasible, identifying susceptible areas is key to guide targeted management actions. This study used species-habitat models to (i) identify the local environmental features of the railway line/watercourse intersections (RLWIs) that make them particularly susceptible to coypu damage, and (ii) predict species occurrence probability in a wide lowland-hilly area of northern Italy (Lombardy) to identify priority areas for monitoring. RESULTS: The local scale models stressed that the RLWIs most susceptible to burrowing were those surrounded by arable lands with interspersed hedgerows locally characterized by high herbaceous vegetation and clay soil. In urbanized and intensive agricultural areas coypu dens were generally located significantly closer to the railway, increasing the collapse risk. The landscape-scale species distribution model showed that lowland areas located along major rivers and lake shores, but also agricultural areas with a dense minor hydrographic network especially in the southeast of the study area, are more likely occupied by the species. CONCLUSION: The local scale models shown that specific environmental characteristics increase the risk of burrowing near RLWIs. The landscape scale model allowed predicting which areas require thorough monitoring of RLWIs in search of such local characteristics to implement preventive management measures. The proposed model-based framework can be applied to any geographical context to predict and prevent coypu damages. This article is protected by copyright. All rights reserved.

12.
J Med Entomol ; 2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38616043

RESUMO

Ehrlichia chaffeensis is a bacterium belonging to the Anaplasmataceae family. In Mexico, only 2 species have been recorded in association with tick species and humans. The objective of the present study was to detect the presence of bacteria of the genus Ehrlichia in ticks collected from the Chamela-Cuixmala Biosphere Reserve, Jalisco, Mexico. The collected ticks were identified and analyzed individually by polymerase chain reaction to amplify a fragment of the Anaplasmataceae 16S rRNA gene and the Ehrlichia-specific dsb gene. A total of 204 ticks, corresponding to 5 species of Ixodidae and 1 of Argasidae, were collected from 147 mammals of 6 species and 4 orders; 57 ticks collected from vegetation were also included. Among the total ticks collected, 1.47% (3/204) was positive for Ehrlichia sp. DNA was obtained using the primers EHR 16SD and EHR 16SR for 16S rRNA and DSB-330 and DSB-728 for dsb. The positive samples corresponded to a larva (Amblyomma sp.) associated with Didelphis virginiana and 2 nymphs (Amblyomma cf. oblongoguttatum) infesting Nasua narica. None of the ticks collected from the vegetation tested positive for Ehrlichia sp. DNA on the basis of the 16S rRNA and dsb genes. The sequences from the larvae of Amblyomma sp. and the nymphs of A. cf. oblongoguttatum were similar to those of E. chaffeensis. The phylogenetic analysis inferred with maximum likelihood corroborated the identity as E. chaffeensis. Although the role of these tick species as vectors of E. chaffeensis is still undetermined, the presence of infected ticks in the area indicates a potential zoonotic risk.

13.
PeerJ ; 12: e17004, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38436024

RESUMO

The mammalian crown originated during the Mesozoic and subsequently radiated into the substantial array of forms now extant. However, for about 100 million years before the crown's origin, a diverse array of stem mammalian lineages dominated terrestrial ecosystems. Several of these stem lineages overlapped temporally and geographically with the crown mammals during the Mesozoic, but by the end of the Cretaceous crown mammals make up the overwhelming majority of the fossil record. The progress of this transition between ecosystems dominated by stem mammals and those dominated by crown mammals is not entirely clear, in part due to a distinct separation of analyses and datasets. Analyses of macroevolutionary patterns tend to focus on either the Mammaliaformes or the non-mammalian cynodonts, with little overlap in the datasets, preventing direct comparison of the diversification trends. Here I analyse species richness and biogeography of Synapsida as a whole during the Mesozoic, allowing comparison of the patterns in the mammalian crown and stem within a single framework. The analysis reveals the decline of the stem mammals occurred in two discrete phases. The first phase occurred between the Triassic and Middle Jurassic, during which the stem mammals were more restricted in their geographic range than the crown mammals, although within localities their species richness remained at levels seen previously. The second phase was a decline in species richness, which occurred during the Lower Cretaceous. The results show the decline of stem mammals, including tritylodontids and several mammaliaform groups, was not tied to a specific event, nor a gradual decline, but was instead a multiphase transition.


Assuntos
Ecossistema , Fósseis , Animais , Mamíferos
14.
Animals (Basel) ; 14(6)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38539919

RESUMO

Matching-to-sample tasks have been a useful method in visual cognitive studies on non-human animals. The use of touch panels in matching-to-sample tasks has contributed to cognitive studies on terrestrial animals; however, there has been a difficulty in using these devices underwater, which is one of the factors that has slowed the progress of visual studies on underwater animals. Cetaceans (e.g., dolphins and whales) are highly adapted to underwater environments, and further studies on their cognitive abilities are needed to advance our understanding of the interactions between environmental factors and the evolution of cognitive abilities. In this study, we aimed to develop a new experimental method in which a captive killer whale performed a matching-to-sample task using a monitor shown through an underwater window as if a touch panel were used. In order to confirm the usefulness of this method, one simple experiment on mirror image discrimination was conducted, and the pairs with mirror images were shown to be more difficult to identify than the pairs with other normal images. The advantages of using this method include (1) simplicity in the devices and stimuli used in the experiments, (2) appropriate and rigorous experimental control, (3) the possibility of increasing the number of individuals to be tested and interspecies comparisons, and (4) contributions to animal welfare. The use of this method solves some of the problems in previous visual cognitive studies on cetaceans, and it suggests the further possibility of future comparative cognitive studies. It is also expected to contribute to animal welfare in terms of cognitive enrichment, and it could help with the proposal of new exhibition methods in zoos and aquariums.

15.
Animals (Basel) ; 14(6)2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38539994

RESUMO

Creative or novel behaviors in bottlenose dolphins (Tursiops truncatus) can be indicators of flexible thinking and problem solving. Over 50 years ago, two rough-tooth dolphins demonstrated creative novel behaviors acquired through reinforcement training in human care. Since this novel training, a variety of species have been trained to respond to this conceptual cue. The current study assessed the creativity of 12 bottlenose dolphins (5 females, 7 males) housed at the Roatan Institute for Marine Sciences (RIMS) in Roatan, Honduras. Individual differences were found across four constructs measured for creativity: fluency, flexibility, elaboration, and originality. Variability in performance occurred across test sessions. Animals with less experience with this task performed fewer "innovative" behaviors as compared to more experienced animals. Despite errors, dolphins continued to attempt the task during test sessions, suggesting the concept of "innovate" was intrinsically rewarding and cognitively engaging. This task may be utilized across species to promote the comparative study of innovative or creative behavior as well as to promote cognitive welfare.

16.
PeerJ ; 12: e16627, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38500531

RESUMO

Background: Dung beetles provide many important ecosystem services, including dung decomposition, pathogen control, soil aeration, and secondary seed dispersal. Yet, the biology of most dung beetles remains unknown. Natural diets are poorly studied, partly because previous research has focused on choice or attraction experiments using few, easily accessible dung types from zoo animals, farm animals, or humans. This way, many links within natural food webs have certainly been missed. In this work, we aimed to establish a protocol to analyze the natural diets of dung beetles using DNA gut barcoding. Methods: First, the feasibility of gut-content DNA extraction and amplification of 12s rDNA from six different mammal dung types was tested in the laboratory. We then applied the method to beetles caught in pitfall traps in Ecuador and Germany by using 12s rDNA primers. For a subset of the dung beetles caught in the Ecuador sampling, we also used 16s rDNA primers to see if these would improve the number of species we could identify. We predicted the likelihood of amplifying DNA using gut fullness, DNA concentration, PCR primer, collection method, and beetle species as predictor variables in a dominance analysis. Based on the gut barcodes, we generated a dung beetle-mammal network for both field sites (Ecuador and Germany) and analyzed the levels of network specificity. Results: We successfully amplified mammal DNA from dung beetle gut contents for 128 specimens, which included such prominent species as Panthera onca (jaguar) and Puma concolor (puma). The overall success rate of DNA amplification was 53%. The best predictors for amplification success were gut fullness and DNA concentration, suggesting the success rate can be increased by focusing on beetles with a full gut. The mammal dung-dung beetle networks differed from purely random network models and showed a moderate degree of network specialization (H2': Ecuador = 0.49; Germany = 0.41). Conclusion: We here present a reliable method of extracting and amplifying gut-content DNA from dung beetles. Identifying mammal dung via DNA reference libraries, we created mammal dung-dung beetle trophic networks. This has benefits over previous methods because we inventoried the natural mammal dung resources of dung beetles instead of using artificial mammal baits. Our results revealed higher levels of specialization than expected and more rodent DNA than expected in Germany, suggesting that the presented method provides more detailed insights into mammal dung-dung beetle networks. In addition, the method could have applications for mammal monitoring in many ecosystems.


Assuntos
Besouros , Ecossistema , Animais , Besouros/genética , DNA Ribossômico , Fezes , Mamíferos
17.
Vision Res ; 218: 108389, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38531191

RESUMO

Harbor seals (Phoca vitulina) need to detect single objects for example when orienting to landmarks or hunting prey. The detection of single objects, described by the single target acuity (STA), cannot be deduced from formerly determined grating acuity (GA) as different mechanisms underlie STA and GA. Thus, we assessed STA for stationary and moving single targets with varying contrast in two harbor seals in a first approach in air. In a two-alternative-forced-choice discrimination task, the seals had to indicate whether the single target was presented in a left or right stimulus field on a monitor. The STA for full-contrast stationary targets was determined as 0.27 deg of visual angle for both experimental animals. Contrary to our expectations, neither adding motion nor reducing contrast had a strong impact on STA. Additionally, we also determined GA in the two harbor seals (1.2 and 1.1 cycles/deg or 0.42 and 0.45 deg for a single stripe of the grating at threshold) to be slightly inferior to STA. Our results are in good correspondence with contrast sensitivity and allow calculating viewing distances in the context of for example visual orientation.


Assuntos
Phoca , Animais , Sensibilidades de Contraste
18.
Ecotoxicol Environ Saf ; 275: 116253, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38537475

RESUMO

Pregnancy is a sensitive window period for bisphenol A (BPA) exposure. BPA can pass through the placenta and cause reproductive damage in offspring female mice. Even BPA that is not metabolized during lactation can be passed through milk. Cuscuta chinensis flavonoids (CCFs) can alleviate reproductive damage caused by BPA, but the mechanism of action is unclear. To investigate the potential mitigating impact of CCFs on ovarian damage resulting from BPA exposure during pregnancy, we administered BPA and CCFs to pregnant mice during the gestational period spanning from 0.5 to 17.5 days. Aseptic collection of serum and ovaries from female mice was conducted on postnatal day 21 (PND21). Serum hormone levels and tissue receptor levels were quantified utilizing ELISA and PCR, while ovaries underwent sequencing and analysis through transcriptomics and metabolomics techniques. Additionally, the assessment of ovarian oxidative stress levels was carried out as part of the comprehensive analysis. The results showed that CCFs administration mitigated the adverse effects induced by BPA exposure on ovarian index, hormone levels, receptor expression, and mRNA expression levels in female offspring mice. The joint analysis of transcriptome and metabolome revealed 48 enriched pathways in positive ion mode and 44 enriched pathways in negative ion mode. Among them, the central carbon metabolism pathway is significantly regulated by BPA and CCFs. The screened sequencing results were verified through qPCR and biochemical kits. In this study, CCFs may participate in the central carbon metabolism pathway by reducing the expression of Kit proto-oncogene (Kit), hexokinase 1 gene (Hk1) and pyruvate kinase M (Pkm) mRNA and increasing the expression of h-ras proto-oncogene (Hras), sirtuin 3 (Sirt3), sirtuin 6 (Sirt6) and TP53 induced glycolysis regulatory phosphatase gene (Tigar) mRNA, thereby resisting the effects of BPA on the body. At the same time, the metabolic levels of D-Fructose 1,6-bisphosphate and L-Asparagine tend to be stable. Moreover, CCFs demonstrated a capacity to diminish the BPA-induced escalation in reactive oxygen species (ROS) and malondialdehyde (MDA). Simultaneously, it exhibited the ability to elevate levels of glutathione (GSH) and catalase (CAT), thereby effectively preventing peroxidation. In summary, CCFs alleviate BPA-induced ovarian damage in offspring female mice by regulating the central carbon metabolism pathway. This study will improve the information on BPA reproductive damage antagonist drugs and provide a theoretical basis for protecting animal reproductive health.


Assuntos
Cuscuta , Disruptores Endócrinos , Fenóis , Sirtuínas , Gravidez , Camundongos , Animais , Feminino , Ovário , Cuscuta/genética , Flavonoides/farmacologia , Compostos Benzidrílicos/toxicidade , Hormônios , RNA Mensageiro , Disruptores Endócrinos/farmacologia
19.
Mar Pollut Bull ; 202: 116294, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38537499

RESUMO

Shipping is one of the largest industries globally, with well-known negative impacts on the marine environment. Despite the known negative short-term (minutes to hours) impact of shipping on individual animal behavioural responses, very little is understood about the long-term (months to years) impact on marine species presence and area use. This study took advantage of a planned rerouting of a major shipping lane leading into the Baltic Sea, to investigate the impact on the presence and foraging behaviour of a marine species known to be sensitive to underwater noise, the harbour porpoise (Phocoena phocoena). Passive acoustic monitoring data were collected from 15 stations over two years. Against predictions, no clear change occurred in monthly presence or foraging behaviour of the porpoises, despite the observed changes in noise and vessel traffic. However, long-term heightened noise levels may still impact communication, echolocation, or stress levels of individuals, and needs further investigation.

20.
Ecol Evol ; 14(3): e11135, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38529024

RESUMO

Determining how animals allocate energy, and how external factors influence this allocation, is crucial to understand species' life history requirements and response to disturbance. This response is driven in part by individuals' energy balance, prey characteristics, foraging behaviour and energy required for essential functions. We developed a bioenergetic model to estimate minimum foraging success rate (FSR), that is, the lowest possible prey capture rate for individuals to obtain the minimum energy intake needed to meet daily metabolic requirements, for female sperm whale (Physeter macrocephalus). The model was based on whales' theoretical energetic requirements using foraging and prey characteristics from animal-borne tags and stomach contents, respectively. We used this model to simulate two prey structure change scenarios: (1) decrease in mean prey size, thus lower prey energy content and (2) decrease in prey size variability, reducing the variability in prey energy content. We estimate the whales need minimum of ~14% FSR to meet their energetic requirements, and energy intake is more sensitive to energy content changes than a decrease in energy variability. To estimate vulnerability to prey structure changes, we evaluated the compensation level required to meet bioenergetic demands. Considering a minimum 14% FSR, whales would need to increase energy intake by 21% (5-35%) and 49% (27-67%) to compensate for a 15% and 30% decrease in energy content, respectively. For a 30% and 50% decrease in energy variability, whales would need to increase energy intake by 13% (0-23%) and 24% (10-35%) to meet energetic demands, respectively. Our model demonstrates how foraging and prey characteristics can be used to estimate impact of changing prey structure in top predator energetics, which can help inform bottom-up effects on marine ecosystems. We showed the importance of considering different FSR in bioenergetics models, as it can have decisive implications on estimates of energy acquired and affect the conclusions about top predator's vulnerability to possible environmental fluctuations.

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