RESUMEN
To study the estrogen regulated transcription of the uteroglobin (UG) gene, the founding member of the secretoglobin family widely expressed in many different mammalian species, we re-created functional estrogen response elements (EREs) in the UG gene promoter from a species where UG expression is not regulated by estrogens: the hamster Mesocricetus auratus (Ma), to ascertain if the lack of functional EREs is the real cause of its estrogen insensitivity. Functional EREs in the hamster promoter, including the consensus ERE (cERE), failed to respond to an appropriate estrogen stimulus compared with its estrogen regulated ortholog from the brown hare Lepus capensis (Lc). As the nucleotide sequence is the only difference between genetic constructs from these two species, we suspected that the UG promoter from the hamster probably contains cis-acting genetic elements that negatively impairs the estrogen-regulated transcription mediated by the functional ERE. Accordingly, we prepared chimeric DNA constructs which eventually allowed to identify a region located 29 base pairs (bp) downstream of the ERE as responsible for the lack of estrogen-responsiveness of the Ma-UG gene in the breast cancer cell line MCF-7. This region contains the sequence ACACCCC which has been identified as the core sequence of the Sp/ Krüppel-like factor (KLF) family of transcription factors. This finding is relevant, not only due to the observation on a novel mechanism that control estrogen-induced transcription, but also because it may encourage further investigation for better defining specific genes with an ERE that do not respond to estrogen signaling in MCF-7 cells, a cell line widely employed as an in vitro model in breast cancer research.
Asunto(s)
Neoplasias de la Mama , Liebres , Cricetinae , Animales , Humanos , Femenino , Células MCF-7 , Uteroglobina/genética , Secuencia de Bases , Estrógenos/farmacología , Estrógenos/metabolismo , Neoplasias de la Mama/genética , Liebres/metabolismo , Transcripción Genética , Estradiol/farmacologíaRESUMEN
A d-galacturonic acid-specific lectin, named AcL, was purified from the sea hare Aplysia californica by galactose-agarose affinity chromatography. AcL has a molecular mass of 27.5 kDa determined by MALDI-TOF mass spectrometry. This lectin shows a good affinity for d-galacturonic acid and a lower affinity for galactosides: raffinose, melibiose, α and ß-lactose, and d-galactose. We determined the amino acid sequence of AcL by trypsin digestion and subsequent peptide analysis by mass spectrometry, resulting in a 238 amino acid protein with a theoretical molecular mass of 26.4 kDa. The difference between the theoretical and experimental values can be attributed to post-translational modifications. Thiol-disulfide quantification discerned five disulfide bonds and three free cysteines. The structure of Acl is mainly comprised of beta sheets, determined by circular dichroism, and predicted with AlphaFold. Theoretical models depict three nearly identical tandem domains consisting of two beta sheets each. From docking analysis, we identified AcL glycan-binding sites as multiple conserved motifs in each domain. Furthermore, phylogenetic analysis based on its structure and sequence showed that AcL and its closest homologues (GalULs) form a clear monophyletic group, distinct from other glycan-binding proteins with a jelly-roll fold: lectins of types F and H. GalULs possess four conserved sequence regions that distinguish them and are either ligand-binding motifs or stabilizing network hubs. We suggest that this new family should be referred to as GalUL or D-type, following the traditional naming of lectins; D standing for depilans, the epithet for the species (Aplysia depilans) from which a lectin of this family was first isolated and described.
Asunto(s)
Aplysia , Liebres , Animales , Aplysia/química , Aplysia/metabolismo , Liebres/metabolismo , Galectinas/química , Filogenia , Galactosa/metabolismo , Polisacáridos/metabolismoRESUMEN
Toll-like receptors (TLRs) are one of the most ancient and widely studied innate immune receptors responsible for host defense against invading pathogens. Among the known TLRs, TLR7 and TLR8 sense and recognize single-stranded (ss) RNAs with a dynamic evolutionary history. While TLR8 was lost in birds and duplicated in turtles and crocodiles, TLR7 is duplicated in some birds, but in other tetrapods, there is only one copy. In mammals, with the exception of lagomorphs, TLR7 and TLR8 are highly conserved. Here, we aim to study the evolution of TLR7 and TLR8 in mammals, with a special focus in the order Lagomorpha. By searching public sequence databases, conducting evolutionary analysis, and evaluating gene expression, we were able to confirm that TLR8 is absent in hares but widely expressed in the European rabbit. In contrast, TLR7 is absent in the European rabbit and quite divergent in hares. Our results suggest that, in lagomorphs, more in particular in leporids, TLR7 and TLR8 genes have evolved faster than in any other mammalian group. The long history of interaction with viruses and their location in highly dynamic telomeric regions might explain the pattern observed.
Asunto(s)
Liebres , Lagomorpha , Animales , Liebres/metabolismo , Conejos , Receptor Toll-Like 7/genética , Receptor Toll-Like 8/genéticaRESUMEN
In Croatia, Podravina is a well-known lead-polluted region due to the intensive exploitation of natural gas, a highly developed agricultural industry, and a traffic hub with several heavily traveled roads. It represents a natural environment with a great variety of wildlife, especially hares (Lepus europaeus Pallas), which may serve as an indicator for environmental quality assessment. This study was conducted to estimate the bioaccumulation of lead in hare liver, kidney, muscle, and brain during long-term exposure and its impact on the oxidative status of the organism and to investigate a possible lead exchange ionic mechanism in the brain. In the organs of two hare groups (experimental from polluted area and control from the island of Krk), Ca, Fe, Mg, Na, lead concentrations, and antioxidant enzyme defense system were analyzed. The accumulation of lead was highest in the brain (3.7-fold higher compared to the control group) and lowest in the liver (1.6-fold higher compared to the control group). Kendall-Tau and multiple regression analysis showed that the increased lead content caused a stronger exchange of Ca and Na ions in the brain. We proposed that lead either mobilizes intracellular cation stores or causes competitive displacement of Ca from the binding site in intoxicated cells. A linear predictive model for cell intoxication by lead was proposed, where GPx and SOD were predominantly influenced by long-term lead exposure. The presented results showed that long-term lead exposure in hares negatively affected their oxidative status and caused the strongest toxicity in the brain and muscles, making their survival and/or population vulnerable.
Asunto(s)
Liebres , Animales , Antioxidantes/metabolismo , Croacia , Biomarcadores Ambientales , Contaminación Ambiental , Liebres/metabolismo , Plomo/metabolismo , Plomo/toxicidad , Gas Natural , Superóxido Dismutasa/metabolismoRESUMEN
Hair cortisol concentration is increasingly used as a convenient, non-invasive, and integrative measure of physiology and health in natural populations of mammals. However, the use of this index is potentially confounded by individual variation in body region-specific differences in cortisol deposition rates. Here we examine correlations in cortisol concentrations in hair collected from the ear, shoulder, and thigh of wild snowshoe hares, Lepus americanus, as well as the influence of sex on cortisol measurements. We further evaluated this technique's ability to capture seasonal and cyclical patterns of snowshoe hare glucocorticoid secretion from 2013 to 2015 in the southwestern Yukon (Canada). We found positive correlations (R2 = 0.20-0.32) in all pairwise comparisons among body regions, and differences among individuals accounted for the greatest proportion of variance (47.3%) in measurements. From 2013 to 2015 the hares' primary predator - Canada lynx - approximately doubled in population abundance. We found a significant increase in hare hair cortisol concentrations across this time period. Cortisol indices were higher in summer than winter pelage, reflecting predicted physiological responses to seasonal variation in food availability and individual risk. Variation in hair cortisol concentrations was more similar to long-term (weeks-months) integrative indices of adrenal capacity than point samples of fecal glucocorticoid metabolite concentrations. Overall, we find that hair cortisol analysis is a simple and useful tool for estimations of population-level stress physiology in wild mammals, and sampling of core body regions with consistent moulting patterns produced the most robust results in this species.
Asunto(s)
Cabello/química , Liebres/anatomía & histología , Liebres/metabolismo , Hidrocortisona/metabolismo , Estaciones del Año , Caracteres Sexuales , Estrés Fisiológico , Animales , Biomarcadores/metabolismo , Canadá , Femenino , Sistema Hipotálamo-Hipofisario/fisiología , Lynx/fisiología , Masculino , Dinámica Poblacional , Conducta PredatoriaRESUMEN
Toll-like receptors (TLRs) are transmembrane proteins of the innate immune system, composed of the ectodomain involved in pathogen recognition and the intracellular Toll/interleukin-1 receptor (TIR) domain important for downstream signal transduction. Here, we analyze the genetic variability of TIR nucleotide and amino-acid sequences of the TLR2 gene in 243 brown hares from Europe and the Middle East and tested for the presence of selection signals and spatial structuring. TLR2 TIR domain sequences were PCR amplified and sequenced, while genotyping was performed by phasing. Genetic diversity indices were calculated in DnaSP and Arlequin, while presence of selection signals was tested using MEGA and the Datamonkey web server. The presence of spatial patterns in TIR sequence distribution was tested by spatial Principal Component Analysis (sPCA) in adegenet. A total of 13 haplotypes were revealed with haplotype diversity of 0.424, and nucleotide diversity (π) of 0.00138. Two spatial clusters were revealed: "Anatolia/Middle East" and "Europe". In Anatolia the two most prevalent amino-acid variants, A and B (the latter being the most ancestral) were maintained at similar frequencies; but in Europe a shift in genotype frequencies was observed as well as a higher number of nonsynonymous substitutions giving rise to novel amino-acid protein variants originating from the evolutionarily younger protein variant. Molecular diversity (haplotype and nucleotide diversity) indices were significantly higher in the "Anatolia/Middle East" cluster. A signal of purifying selection was detected acting on the TIR sequences.
Asunto(s)
Liebres/genética , Receptor Toll-Like 2/genética , Alelos , Animales , Evolución Biológica , Europa (Continente) , Evolución Molecular , Variación Genética/genética , Genotipo , Haplotipos/genética , Liebres/metabolismo , Medio Oriente , Filogenia , Selección Genética/genética , Análisis de Secuencia de ADN/métodos , Receptor Toll-Like 2/metabolismo , Receptores Toll-Like/genéticaRESUMEN
Water transport across epithelial cells that line the airways and alveoli is a crucial component of lung physiology. Aquaporins (AQPs) facilitate water transport across the air space-capillary barrier in the distal lung. However, the roles of lung AQPs in desert animal adaptation to dry airstream environments are still unclear. A hare (Lepus yarkandensis) only lives in the Tarim Basin, and its living environment is an arid climate with rare precipitation. We studied cellular localization and expression levels of AQP1, AQP3, AQP4 and AQP5 in L. yarkandensis lungs by immunohistochemistry, quantitative real-time polymerase chain reaction and Western blot. The lung of rabbits (Oryctolagus cuniculus) that inhabit in mesic environment was similarly studied. Obtained results in two species of animals were compared to investigate whether AQPs in the lung altered expression in the animal living in arid region. AQP1 was localized to the endothelial cells in capillaries and venules surrounding terminal bronchioles and alveoli. AQP5 was localized to the ciliated columnar cells in terminal bronchioles and the alveolar type I cells in the alveolus. Quantitative real-time PCR analysis showed higher AQP1 and AQP5 mRNA levels in L. yarkandensis compared to O. cuniculus. Similar results were obtained by Western blot. These results revealed that the higher expression levels of AQP1 and AQP5 played a significant role in water transport in the lungs of arid-desert living L. yarkandensis and might accelerate water transport from capillary compartments to the airspace.
Asunto(s)
Acuaporinas/metabolismo , Clima Desértico , Ecosistema , Regulación de la Expresión Génica/fisiología , Liebres/metabolismo , Pulmón/metabolismo , Animales , Acuaporinas/genética , Agua/metabolismoRESUMEN
In natural populations, allelic diversity of the major histocompatibility complex (MHC) is commonly interpreted as resulting from positive selection in varying spatiotemporal pathogenic landscapes. Composite pathogenic landscape data are, however, rarely available. We studied the spatial distribution of allelic diversity at two MHC class II loci (DQA, DQB) in hares, Lepus capensis, along a steep ecological gradient in North Africa and tested the role of climatic parameters for the spatial distribution of DQA and DQB proteins. Climatic parameters were considered to reflect to some extent pathogenic landscape variation. We investigated historical and contemporary forces that have shaped the variability at both genes, and tested for differential selective pressure across the ecological gradient by comparing allelic variation at MHC and neutral loci. We found positive selection on both MHC loci and significantly decreasing diversity from North to South Tunisia. Our multinomial linear models revealed significant effects of geographical positions that were correlated with mean annual temperature and precipitation on the occurrence of protein variants, but no effects of co-occurring DQA or DQB proteins, respectively. Diversifying selection, recombination, adaptation to local pathogenic landscapes (supposedly reflected by climate parameters) and neutral demographic processes have shaped the observed MHC diversity and differentiation patterns.
Asunto(s)
Genes MHC Clase II/genética , Liebres/genética , Liebres/inmunología , África del Norte , Alelos , Animales , Clima , Ecología , Ecosistema , Evolución Molecular , Frecuencia de los Genes/genética , Variación Genética/genética , Geografía , Liebres/metabolismo , Repeticiones de Microsatélite/genética , Filogenia , Selección Genética/genética , Alineación de Secuencia/métodos , TúnezRESUMEN
To evaluate the influence of hazardous substances in the environment, studies of pollutant accumulation in wild living animals are needed. Studies dealing with heavy metal contamination in mammals usually focus on a single organ. We investigated accumulation of heavy metals as well as iron in European hare (Lepus europaeus) living in southern Poland, Malopolska Province. Hares were captured during the hunting season. We tested metal accumulation in 14 organs and tissues using 35 individuals with known body weight and sex inhabiting agricultural, industrial and other types of landscapes. To obtain deeper insight into contamination patterns, we used accumulation data from the liver since it is the most frequently investigated organ and prone to pollution accumulation. Based on the data obtained for the liver, we tested the impact of metal pollution on hare morphology, including body length and several skull cranimetric parameters. Metals content differed between organs. Moreover, individuals from industrial areas had higher Cd content in their body. We distinguished two groups of elements: the first group, Cd, Fe and Zn, revealed the highest toxic effect in the liver and kidneys; the second group, Cr, Ni, and Pb, accumulated primarily in the brain. Hares inhabiting industrial areas had higher concentration of Cd and Pb, and lower levels of Cr and Fe in their liver in comparison with those from agricultural and forest habitats. Heavy metals had an effect on body length that was negatively associated with Cr levels. Skull diastema length was associated positively with accumulation of Cd and Pb. We showed that hare organs and tissues could be used as bioindicators of environmental pollution by heavy metals.
Asunto(s)
Tamaño Corporal/efectos de los fármacos , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Liebres/crecimiento & desarrollo , Metales Pesados/análisis , Tamaño de los Órganos/efectos de los fármacos , Agricultura , Animales , Cefalometría , Contaminantes Ambientales/toxicidad , Liebres/metabolismo , Industrias , Hígado/química , Hígado/efectos de los fármacos , Metales Pesados/toxicidad , Especificidad de Órganos , PoloniaRESUMEN
Egg lectins occur in a variety of animals ranging from mollusks to vertebrates. A few examples of molluscan egg lectins have been reported, including that of the sea hare Aplysia kurodai; however, their biological functions in the egg remain unclarified. We report the isolation, determination of primary structure, and possible functions of A.kurodai lectin (AKL) from the egg mass of A. kurodai. We obtained AKL as an inseparable mixture of isoproteins with a relative molecular mass of approximately 32 kDa by affinity purification. The hemagglutinating activity of AKL against rabbit erythrocytes was inhibited most potently by galacturonic acid and moderately by xylose. Nucleotide sequencing of corresponding cDNA obtained by rapid amplification of cDNA ends (RACE) allowed us to deduce complete amino acid sequences. The mature polypeptides consisted of 218- or 219-amino acids with three repeated domains. The amino acid sequence had similarities to hypothetical proteins of Aplysia spp., or domain DUF3011 of uncharacterized bacterial proteins. AKL is the first member of the DUF3011 family whose function, carbohydrate recognition, was revealed. Treatment of the egg with galacturonic acid, an AKL sugar inhibitor, resulted in deformation of the veliger larvae, suggesting that AKL is involved in organogenesis in the developmental stage of A. kurodai.
Asunto(s)
Aplysia/genética , Aplysia/metabolismo , Liebres/genética , Liebres/metabolismo , Ácidos Hexurónicos/metabolismo , Lectinas/genética , Lectinas/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , ADN Complementario/genética , Eritrocitos/metabolismo , ConejosRESUMEN
The goal of this study was to monitor the accumulation of aflatoxin B1 in the liver and kidney of brown hares (Lepus europaeus Pall) in the region of south-western Slovakia. A total of 65 samples were involved for analysis by RIA method. Brown hares were divided into the groups according to age, sex and season (month). The sex was determined visually after shooting, and the age was assigned from dried eye lens. The average concentration of AFB1 in the liver of hares was 0.54 ± 0.053 µg/kg, and lower values were measured in the kidney (0.41 ± 0.038 µg/kg). The significantly (P < 0.05) higher values were found in winter months when compared to summer months. According to the age, juvenile animals showed significant higher accumulation of B1 in both organs than adults (P < 0.05). Wild animals can serve as a good model of real environmental contamination. Thus, monitoring of risk factors such as mycotoxins in the environment is important with regard to public health, as game animals constitute an important part of food chain for humans.
Asunto(s)
Aflatoxina B1/análisis , Liebres/metabolismo , Riñón/química , Hígado/química , Estaciones del Año , Aflatoxina B1/metabolismo , Factores de Edad , Animales , Animales Salvajes , Contaminación Ambiental/análisis , Femenino , Riñón/metabolismo , Hígado/metabolismo , Masculino , Factores Sexuales , EslovaquiaRESUMEN
The European brown hare (Lepus europaeus, Pallas 1778) is an important small game species in Europe. Due to its size and position in the food chain, as well as its life history, phenotypic variation and the relatively recent speciation events, brown hare plays an important role in the structure of various ecosystems and has emerged as an important species for population management and evolutionary studies. In order to identify informative SNPs for such studies, heart and liver tissues of three samples from the European lineage and a three-sample pool from the Anatolian lineage were subjected to RNA-Sequencing analysis. This effort resulted in 9496 well-assembled protein-coding sequences with close homology to human. After applying very stringent filtering criteria, 66185 polymorphic sites were identified in 7665 genes/cds and 2050 of those polymorphic sites are potentially capable of distinguishing the European from the Anatolian lineage. From these distinguishing mutations we focused on those in genes that are involved in cellular energy production, namely the glycolysis, Krebs cycle and the OXPHOS machinery. A selected set of SNPs was also validated by Sanger sequencing. By simulating the three European individuals as one pool, no substantial informative-SNP identification was lost, making it a cost-efficient approach. To our knowledge this is the first attempt to correlate the differentiation in both nuclear and mitochondrial genome between the two different lineages of L. europaeus with the observed spatial partitioning of the lineages of the species, proposing a possible mechanism that is maintaining the reproductive isolation of the lineages.
Asunto(s)
Metabolismo Energético , Liebres/genética , Polimorfismo de Nucleótido Simple , Transcriptoma , Animales , Especiación Genética , Liebres/clasificación , Liebres/metabolismo , MutaciónRESUMEN
A preliminary study was undertaken to determine post-mining baseline accumulation of selected trace metals, and histopathological alterations in free-living arctic hares (Lepus arcticus) inhabiting the vicinity of a former lead-zinc mine located on North Baffin Island in the Canadian High Arctic. Trace metal analysis included measurement of As, Cd, Fe, Pb and Zn in tissues, and histopathological assessment comprised of evaluation and scoring the severity of metal-induced hepatic and renal lesions. Metal contents in hepatic and renal tissues from hares from the mine area compared with the reference locations did not differ significantly suggesting that the animals are not uniformly exposed to background levels of metals in the environment. However, relatively higher accumulation pattern of Pb and Cd were noted in liver tissues of hare from the mine area compared to the background area, but did not induce increased lesions. Surface soils near the mine area contained relatively higher levels of trace metals (Zn>Mn>Pb>Cd>As) compared to reference soils, and with soil levels of Cd showing strong correlation with Cd accumulation in kidney tissues. Generally, both case and reference animals showed similar but varying severities of hepatic and renal lesions at the sublethal level, notably vascular congestion, occasional large hepatocyte nuclei, binucleate hepatocytes, yellow-brown pigmentation in the cytoplasm of hepatocytes and clustering of lymphocytes. Only hares with relatively higher accumulation of Pb from the mine area showed evidence of renal edema and hemorrhage of the capsular surface. This study constitutes the first assessment of metal induced histopathological alterations in arctic hares exposed to a historical mining area in the high arctic.
Asunto(s)
Monitoreo del Ambiente , Liebres/metabolismo , Metales Pesados/metabolismo , Minería , Contaminantes del Suelo/metabolismo , Animales , Regiones Árticas , Canadá , Plomo , ZincRESUMEN
Radiation dose to biota is generally calculated using Monte Carlo simulations of whole body ellipsoids with homogeneously distributed radioactivity throughout. More complex anatomical phantoms, termed voxel phantoms, have been developed to test the validity of these simplistic geometric models. In most voxel models created to date, human tissue composition and density values have been used in lieu of biologically accurate values for non-human biota. This has raised questions regarding variable tissue composition and density effects on the fraction of radioactive emission energy absorbed within tissues (e.g. the absorbed fraction - AF), along with implications for age-dependent dose rates as organisms mature. The results of this study on rabbits indicates that the variation in composition between two mammalian tissue types (e.g. human vs rabbit bones) made little difference in self-AF (SAF) values (within 5% over most energy ranges). However, variable tissue density (e.g. bone vs liver) can significantly impact SAF values. An examination of differences across life-stages revealed increasing SAF with testis and ovary size of over an order of magnitude for photons and several factors for electrons, indicating the potential for increasing dose rates to these sensitive organs as animals mature. AFs for electron energies of 0.1, 0.2, 0.4, 0.5, 0.7, 1.0, 1.5, 2.0, and 4.0 MeV and photon energies of 0.01, 0.015, 0.02, 0.03, 0.05, 0.1, 0.2, 0.5, 1.0, 1.5, 2.0, and 4.0 MeV are provided for eleven rabbit tissues. The data presented in this study can be used to calculate accurate organ dose rates for rabbits and other small rodents; to aide in extending dose results among different mammal species; and to validate the use of ellipsoidal models for regulatory purposes.
Asunto(s)
Liebres/metabolismo , Modelos Biológicos , Fantasmas de Imagen/veterinaria , Dosis de Radiación , Monitoreo de Radiación/instrumentación , Monitoreo de Radiación/métodos , Animales , Carga Corporal (Radioterapia) , Simulación por Computador , Electrones , Femenino , Masculino , Método de Montecarlo , Fotones , Distribución TisularRESUMEN
Environmental impact of natural gas facility near Molve (Podravina, Croatia) was assessed using hares (Lepus europaeus Pallas) as biomonitors. Elevated levels of heavy metals in the environment lead to their accumulation in different tissues of hares. The authors have tested accumulation and distribution of several metals in hare liver, kidney, and muscle tissues. The accumulation of copper in hare liver and kidneys with concomitant decrease of zinc was observed in animals from Podravina region as opposed to the control group of animals (Island Krk, Croatia). Secondly, the expression of metallothioneins was assessed because of their crucial role in metal homeostasis. Observed elevation of metallothionein expression in tested organs emphasizes the possible prolonged negative effects of heavy metals in the surroundings as well as a state of oxidative stress in animals. Further monitoring of the area is necessary for better control of hydrocarbon processing to diminish the possible negative environmental effects.
Asunto(s)
Expresión Génica/efectos de los fármacos , Liebres/genética , Liebres/metabolismo , Metalotioneína/genética , Metales/metabolismo , Metales/toxicidad , Yacimiento de Petróleo y Gas , Animales , Croacia , Masculino , Metalotioneína/metabolismo , Metales/análisis , Distribución TisularRESUMEN
There is little data on the elemental composition of wild animals fur. In the paper, an attempt has been made to evaluate the concentration of elements in the fur of roe deer, wild boar and hare. The contents of following elements: calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), lead (Pb), cadmium (Cd), aluminium (Al), chromium (Cr), nickel (Ni) were determined by atomic absorption spectrometry method. Their content was in the range 0.01 (Cd) to 1,519 (Ca) µg/g. Correlations between the content of Mn, Al, Ca, Pb, Cr, Ni in the fur of animals, liver and muscle tissues were found. Thus it can be assumed that the fur of wild animals can provide an information on the bioavailability of elements and environmental exposure and can be considered as an useful biomarker in animals and environmental studies, although research on this subject should be continued.
Asunto(s)
Animales Salvajes/metabolismo , Cabello/química , Metales/análisis , Animales , Ciervos/metabolismo , Exposición a Riesgos Ambientales/análisis , Cabello/metabolismo , Liebres/metabolismo , Hígado/química , Hígado/metabolismo , Metales/metabolismo , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Espectrofotometría Atómica , Estadística como Asunto , Sus scrofa/metabolismoRESUMEN
Cadmium occurs naturally in the environment and as an anthropogenic pollutant. Exposure to low concentrations of cadmium is inevitable and may produce toxic effects. Another important aspect of cadmium toxicity is its interaction, often antagonistic, with essential elements such as selenium. The aim of this study was to highlight the risks of long-term exposure to low cadmium concentrations, using a scientific and chemical approach and hares (Lepus europaeus Pallas) as model organisms in a field study. Two study areas were monitored. Levels of cadmium and selenium were quantified in the organs of hares, the expression of metallothioneins I + II and the products of lipid peroxidation were determined. The median cadmium concentrations (wet weight) in the muscle, liver, kidney and brain of hares from an exposed group ranged from 0.033 to 0.037, 0.763 to 1.054, 3.090 to 16.594 and 0.016 to 0.087 µg g(-1), respectively; whereas, the median selenium concentrations (wet weight) ranged from 0.100 to 0.108, 0.153 to 0.332, 0.677 to 0.701 and 0.078 to 0.116 µg g(-1), respectively. Expression of the metallothioneins I + II proteins was observed in tissues. Lipid peroxidation (LPO) levels, measured as malondialdehyde (MDA) equivalents, increased with the cadmium concentration. Further research on long-term exposure to low concentrations of cadmium in the environment is needed.
Asunto(s)
Cadmio/toxicidad , Contaminantes Ambientales/toxicidad , Liebres/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Metalotioneína/biosíntesis , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Cadmio/farmacocinética , Croacia , Relación Dosis-Respuesta a Droga , Monitoreo del Ambiente , Contaminantes Ambientales/farmacocinética , Riñón/efectos de los fármacos , Riñón/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Malondialdehído/metabolismo , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Especificidad de Órganos , Selenio/metabolismo , Factores de Tiempo , Distribución TisularRESUMEN
The macro- and microstructures of the surface of the mucous membrane of the gastrointestinal tract were studied in detail in two hare species (Lepus europaeus and L. timidus) using scanning electron and digital microscopes. The morphology of the gastrointestinal tract of hares, which is similar in the two species studied, was described in detail. The macrostructure of the inner surface of the ileocecal junction was investigated. The particularities of the architectonics of the mucous membrane of the intestine that are specific for hares were revealed. In the jejunum of both hare species, the mucous membrane is represented by villi with merged bases, which form circular plates. The mucosa of the colon forms large conical villi, the surface of which is scattered with secreting cells. The possible functional significance of the revealed morphological particularities is discussed.
Asunto(s)
Coprofagia/fisiología , Liebres/metabolismo , Mucosa Intestinal/metabolismo , Membrana Mucosa/ultraestructura , Animales , Haplotipos , Liebres/fisiología , Intestinos/ultraestructura , Membrana Mucosa/metabolismo , Filogenia , Especificidad de la EspecieRESUMEN
The application of species distribution models (SDMs) in ecology and conservation biology is increasing and assuming an important role, mainly because they can be used to hindcast past and predict current and future species distributions. However, the accuracy of SDMs depends on the quality of the data and on appropriate theoretical frameworks. In this study, comprehensive data on the current distribution of the Iberian hare (Lepus granatensis) were used to i) determine the species' ecogeographical constraints, ii) hindcast a climatic model for the last glacial maximum (LGM), relating it to inferences derived from molecular studies, and iii) calibrate a model to assess the species future distribution trends (up to 2080). Our results showed that the climatic factor (in its pure effect and when it is combined with the land-cover factor) is the most important descriptor of the current distribution of the Iberian hare. In addition, the model's output was a reliable index of the local probability of species occurrence, which is a valuable tool to guide species management decisions and conservation planning. Climatic potential obtained for the LGM was combined with molecular data and the results suggest that several glacial refugia may have existed for the species within the major Iberian refugium. Finally, a high probability of occurrence of the Iberian hare in the current species range and a northward expansion were predicted for future. Given its current environmental envelope and evolutionary history, we discuss the macroecology of the Iberian hare and its sensitivity to climate change.
Asunto(s)
Ecología , Liebres/genética , Algoritmos , Animales , Evolución Biológica , Calibración , Clima , Cambio Climático , ADN Mitocondrial/genética , Geografía , Liebres/metabolismo , Modelos Biológicos , Modelos Estadísticos , Dinámica Poblacional , Probabilidad , España , Especificidad de la EspecieRESUMEN
This study aimed at obtaining the data on the occurrence, levels and correlations of organic pollutants present in game animals (n = 75, Brown hare, Lepus europaeus Pall.) in the region of south-western Slovakia. The analyses performed included dichlorodiphenyltrichloroethane (DDT), hexachlorobenzen (HCB), alpha- and beta hexachlorocyclohexane (α+ß-HCH), gamma-hexachlorocyclohexane (γ-HCH), and polychlorinated biphenyls (PCB-delor, commercial mixture of PCB congeners). A gas chromatograph with an electron capture detector was used for the analysis. PCB-delor and DDT were accumulated significantly in the highest level (0.105 ± 0.059 mg/kg; 0.070 mg/kg) in depot fat in brown hares; however maximum permissible limits for the observed pollutants were not exceeded. Significantly higher concentrations of DDT, HCB, γ-HCH, and PCB-delor were found in adult animals when compared with juvenile hares. Gender and season had no effect on the accumulation of observed pollutants. Moderately positive correlation was found between PCB-delor and DDT (r = 0.59). Monitoring of environmental pollution with polychlorinated hydrocarbons is important with regard to public health, as game animals constitute an important part of food chain also for humans.