RESUMEN
BACKGROUND: The importance of upper airway structure in the susceptibility of the lower respiratory tract to colonization with potential pathogens is well established. With the advent of rapid, high throughput, next generation sequencing, there is a growing appreciation of the importance of commensal microbial populations in maintaining mucosal health, and a realization that bacteria colonize anatomical locations that were previously considered to be sterile. While upper respiratory tract microbial populations have been described, there are currently no published studies describing the normal microbial populations of the bovine lower respiratory tract. Consequently, we have little understanding of the relationship between upper and lower respiratory tract microbiota in healthy cattle. The primary objective of our study was to characterize the composition, structure and relationship of the lower and upper respiratory microbial communities in clinically healthy feedlot cattle. Nasopharyngeal swabs (NPS), and bronchoalveolar lavage (BAL) fluid, were collected from clinically healthy feedlot calves (n = 8). Genomic DNA from each sample was extracted, and the V3-V4 hypervariable region of the bacterial 16S rRNA gene was amplified and sequenced using Illumina Miseq platform. RESULTS: Across all samples, the most predominant phyla were Proteobacteria, Actinobacteria and Firmicutes. The most common genera were Rathayibacter, Mycoplasma, Bibersteinia and Corynebacterium. The microbial community structure was distinct between these two biogeographical sites. Most of the bacterial genera identified in the BAL samples were also present in the NPS, but biogeographical-specific genera were enriched in both the NPS (Rathayibacter) and BAL (Bibersteinia) samples. There were strong associations between the presence of certain taxa at each specific location, and strong correlations between the presence of specific taxa in both the NPS and BAL samples. CONCLUSIONS: The correlation between the presence of specific taxa in both the NPS and BAL samples, supports the notion of a mutualistic interrelationship between these microbial communities. Future studies, in large cohorts of animals, are needed to determine the role and clinical importance of the relationships of respiratory tract microbial communities with health, productivity, and susceptibility to the development of respiratory disease, in growing cattle.
Asunto(s)
Bacterias/clasificación , Líquido del Lavado Bronquioalveolar/microbiología , Nasofaringe/microbiología , Análisis de Secuencia de ADN/métodos , Animales , Bacterias/genética , Bacterias/aislamiento & purificación , Bovinos , ADN Bacteriano/genética , Microbiota , Especificidad de Órganos , Filogenia , ARN Ribosómico 16S/genética , SimbiosisRESUMEN
The impact of maternal microbial influences on the early choreography of the neonatal calf microbiome were investigated. Luminal content and mucosal scraping samples were collected from ten locations in the calf gastrointestinal tract (GIT) over the first 21 days of life, along with postpartum maternal colostrum, udder skin, and vaginal scrapings. Microbiota were found to vary by anatomical location, between the lumen and mucosa at each GIT location, and differentially enriched for maternal vaginal, skin, and colostral microbiota. Most calf sample sites exhibited a gradual increase in α-diversity over the 21 days beginning the first few days after birth. The relative abundance of Firmicutes was greater in the proximal GIT, while Bacteroidetes were greater in the distal GIT. Proteobacteria exhibited greater relative abundances in mucosal scrapings relative to luminal content. Forty-six percent of calf luminal microbes and 41% of mucosal microbes were observed in at-least one maternal source, with the majority being shared with microbes on the skin of the udder. The vaginal microbiota were found to harbor and uniquely share many common and well-described fibrolytic rumen bacteria, as well as methanogenic archaea, potentially indicating a role for the vagina in populating the developing rumen and reticulum with microbes important to the nutrition of the adult animal.
Asunto(s)
Tracto Gastrointestinal/microbiología , Microbiota , Animales , Animales Recién Nacidos , Bovinos , Calostro/microbiología , Euryarchaeota , Femenino , Tracto Gastrointestinal/crecimiento & desarrollo , Madres , Membrana Mucosa/microbiología , Embarazo , Rumen/microbiología , Vagina/microbiologíaRESUMEN
Epizootic bovine abortion (EBA), or foothill abortion as it has often been termed, is a tick-borne disease of pregnant cattle recognized in California, Nevada and Oregon. The primary objective of this study was to better define the relationship of a novel deltaproteobacterium, the putative etiological agent of EBA (aoEBA), with the Pajaroello tick (Ornithodoros coriaceus Koch), the recognized vector of EBA. Three developmental stages of O. coriaceus (larva, nymph, and adult) were collected from five locations in California, Nevada and Oregon. A polymerase chain reaction (PCR), developed for detection of aoEBA, was applied to DNA extracted from ticks. Southern blotting of the PCR products increased the number of ticks determined to be carrying the bacteria by seven-fold, suggesting the majority of infected ticks carry relatively low numbers of the pathogen. An effort was made to determine if an artificial blood meal would stimulate replication of the bacterial pathogen, thereby increasing the frequency in which aoEBA could be identified; no statistically significant effect was evident. The number of ticks determined to be carrying aoEBA varied with geographic location and ranged from 5 to 20%. aoEBA was found in both adults (12% of the males and 12% of the females) and nymphs (13%) but not larvae. Comparative analysis of dissected ticks provided strong evidence that the salivary gland was the most common location of aoEBA in field-collected ticks. No significant correlations were identified between the frequency of infection and tick weight, suggesting that increasing tick age and increased number of blood meals did not increase infectivity.
Asunto(s)
Aborto Veterinario/veterinaria , Vectores Arácnidos/microbiología , Enfermedades de los Bovinos/microbiología , Deltaproteobacteria/fisiología , Ornithodoros/microbiología , Aborto Veterinario/microbiología , Animales , Peso Corporal , Bovinos , Enfermedades de los Bovinos/parasitología , Enfermedades de los Bovinos/transmisión , Cartilla de ADN/química , Deltaproteobacteria/genética , Deltaproteobacteria/aislamiento & purificación , Deltaproteobacteria/patogenicidad , Femenino , Geografía , Estadios del Ciclo de Vida , Masculino , Reacción en Cadena de la Polimerasa/veterinaria , Sensibilidad y Especificidad , Infestaciones por Garrapatas/parasitología , Infestaciones por Garrapatas/veterinariaRESUMEN
A 2-month-old Simmental heifer presented for acute onset of neurological behavior. Laboratory tests confirmed the presence of hyponatremia, hypochloremia, and hypokalemia that improved with intravenous fluid therapy. Despite an initial cessation of neurological signs, symptoms re-emerged, and the heifer was euthanized due to poor prognosis. A pituitary abscess (Trueperella pyogenes) was observed on gross necropsy, suggesting that the effects of panhypopituitarism (inappropriate anti-diuretic hormone (ADH), adrenocorticotropic hormone (ACTH), and/or thyroid-stimulating hormone (TSH) secretion) may have resulted in the clinical findings. Pituitary abscess syndrome carries a poor prognosis due to the inability to penetrate the area with systemic antibiotic therapy. These findings highlight the unusual clinical presentations that may occur following pituitary abscess syndrome in cattle that practitioners need to consider when determining prognosis.
RESUMEN
OBJECTIVE: To determine the nucleotide sequence of the equine intestinal fatty acid binding protein (I-FABP) gene, its expression in various regions of the gastrointestinal tract, and the use of measuring I-FABP in horses with colic. Animals-86 horses with colic. PROCEDURE: The mRNA sequence for the I-FABP gene was obtained by use of a rapid amplification of complementary DNA ends technique. Comparative I-FABP gene expression was quantitated by use of a real-time reverse transcription-polymerase chain reaction assay. Amounts of I-FABP in abdominal fluid and plasma were measured by use of an ELISA kit. Association between I-FABP concentrations and clinical variables was performed by nonparametric analysis, and associations of these variables with intestinal ischemia were determined by the Spearman correlation test. RESULTS: The nucleotide sequence had 87% identity with human I-FABP The I-FABP gene was highly expressed in the small intestinal mucosa but had low expression in the colon. High concentrations of I-FABP in abdominal fluid correlated with an increase in protein concentrations in peritoneal fluid and nonsurvival, whereas plasma I-FABP concentrations correlated with the necessity for abdominal surgery. Clinical variables associated with intestinal ischemia included the color and protein content of abdominal fluid and serum creatine kinase activity. CONCLUSIONS AND CLINICAL RELEVANCE: Determination of I-FABP concentrations in abdominal fluid and plasma may be useful for predicting survival and the need for abdominal surgical intervention in horses with colic. Furthermore, serum creatine kinase activity and color and protein concentrations of abdominal fluid may be useful in the diagnosis of intestinal ischemia.
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Proteínas Portadoras/sangre , Proteínas Portadoras/genética , Cólico/veterinaria , Expresión Génica , Enfermedades de los Caballos/sangre , Animales , Ascitis/metabolismo , Ascitis/veterinaria , Aspartato Aminotransferasas/sangre , Biomarcadores/sangre , Cólico/sangre , Colon/metabolismo , Creatina Quinasa/sangre , Ensayo de Inmunoadsorción Enzimática/veterinaria , Proteínas de Unión a Ácidos Grasos , Femenino , Caballos , Inmunohistoquímica/veterinaria , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Masculino , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Homología de Secuencia de Ácido Nucleico , gamma-Glutamiltransferasa/sangreRESUMEN
Phocine herpesvirus-1 (PhHV-1) causes regular outbreaks of disease in neonatal harbor seals (Phoca vitulina) at rehabilitation centers in Europe and in the U.S. To investigate transmission of this virus samples were collected from harbor seal pups during exposure studies at a Californian rehabilitation center from 1999 to 2002 and from free-ranging harbor seals off central California during the same period. The exposure studies provided evidence that PhHV-1 can be transmitted horizontally between animals most likely through direct contact with oro-nasal secretions. However vertical transmission may also occur, as adult female harbor seals were found to be shedding the virus in vaginal and nasal secretions, and premature newborn pups had evidence of early infection. Results also indicated that PhHV-1 infections were common in both free-ranging (40%, 49/121) and rehabilitating (54%, 46/85) young harbor seals, during the spring and early summer. This timing, which correlated with pupping and weaning, suggested that the majority of animals were infected and infective with PhHV-1 between pupping and breeding.
Asunto(s)
Alphaherpesvirinae/aislamiento & purificación , Transmisión de Enfermedad Infecciosa/veterinaria , Infecciones por Herpesviridae/veterinaria , Transmisión Vertical de Enfermedad Infecciosa/veterinaria , Phoca/virología , Factores de Edad , Animales , Animales Recién Nacidos , Animales Lactantes , Animales Salvajes , California/epidemiología , Femenino , Infecciones por Herpesviridae/epidemiología , Infecciones por Herpesviridae/transmisión , Hospitales Veterinarios , Masculino , Reacción en Cadena de la Polimerasa/veterinaria , Prevalencia , Estaciones del Año , Esparcimiento de VirusRESUMEN
The incidence of neoplasia in California sea lions (CSLs) is considered to be unusually high. Electron microscopic examination of some of these urogenital tumours revealed the presence of virions with typical herpes-like structure. While current attempts to cultivate this virus have not been successful, molecular studies employing DNA extracted from tumour tissues allowed both the classification of the agent and its identification in tumours and archived tissue samples. Two genome fragments generated using degenerate primers in PCR demonstrated highest identities with other mammalian gammaherpesviruses. Phylogenetic analysis showed that this novel virus, tentatively designated Otarine herpesvirus-1 (OtHV-1), grouped with members of the gammaherpesvirus subfamily and was distinct from PHV-2, a previously described pinniped gammaherpesvirus. An OtHV-1 specific PCR was established and used to investigate the presence of this virus in CSL tissues. PCR of DNA isolated from animals with these tumours, demonstrated that this virus was present in 100% (16/16) of tumours. Furthermore, DNA extracted from archived brain and muscle tissues was also positive in 29% (4/14) and 50% (7/14) of cases examined. This preliminary study provides evidence to support the hypothesis that the presence of this novel gammaherpesvirus is a factor in the development of urogenital carcinoma in CSLs.
Asunto(s)
Carcinoma/veterinaria , Gammaherpesvirinae/genética , Leones Marinos/virología , Neoplasias Urogenitales/veterinaria , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Carcinoma/genética , Carcinoma/virología , ADN Viral/química , ADN Viral/aislamiento & purificación , Gammaherpesvirinae/química , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Neoplasias Urogenitales/genética , Neoplasias Urogenitales/virologíaRESUMEN
The relationship between exposure to environmental contaminants and immunotoxicity in vulnerable marine species is unknown. In this study, we used American mink (Mustela vision) as a surrogate species for the sea otter to examine the immunotoxic effects of chronic exposure to a low concentration of bunker C fuel oil (500 ppm admixed in the feed for 113-118 days). The mink immune system was monitored over time by flow cytometric analysis for alterations in the immunophenotype of blood lymphocytes and monocytes and by mitogen-stimulated proliferation assays for changes in peripheral blood mononuclear cell function. Fuel oil exposure caused a mild, yet significant (P < 0.05) increase in the absolute numbers of specific peripheral blood lymphocyte subsets (CD3+T cells) and monocytes, an increase in the level of expression of functionally significant cell surface proteins (MHC II, CD18), and an increase in mitogen-induced mononuclear cell proliferative responses. This heightened state of cellular activation along with the increase in specific cell surface protein expression on both the innate and adaptive immune cells is similar to the pro-inflammatory or "adjuvant-like" effect described in laboratory models of polycyclic aromatic hydrocarbon exposure in other species. These results show the benefits of using a controlled laboratory model for detecting and characterizing subtle petroleum oil-induced perturbations in immune responses. In addition this study establishes a framework for studying the effects of environmental petroleum oil exposure on the immune system of free-ranging marine mammals. Expansion of these studies to address biolgical significance is warranted.
Asunto(s)
Aceites Combustibles/toxicidad , Leucocitos Mononucleares/efectos de los fármacos , Visón/inmunología , Contaminantes Químicos del Agua/toxicidad , Animales , Antígenos CD/inmunología , Recuento de Células Sanguíneas/veterinaria , Concanavalina A/inmunología , Citometría de Flujo/veterinaria , Inmunofenotipificación/veterinaria , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/inmunología , Activación de Linfocitos/efectos de los fármacos , Activación de Linfocitos/inmunología , Subgrupos Linfocitarios/efectos de los fármacos , Subgrupos Linfocitarios/inmunología , Masculino , Visón/sangre , Mitógenos de Phytolacca americana/inmunología , Distribución Aleatoria , Contaminantes Químicos del Agua/inmunologíaRESUMEN
Phocine herpesvirus-1 (PhHV-1) has been associated with morbidity and high mortality in neonatal harbor seals (Phoca vitulina) along the Pacific coast of California (USA) and in northern Europe. Seals dying with PhHV-1 associated disease in California primarily have histopathologic evidence of adrenal necrosis or adrenalitis with herpesviral inclusion bodies. Little is known about prevalence of exposure to PhHV-1, modes of disease transmission, and viral pathogenesis in free-ranging harbor seal populations. To evaluate the prevalence in North America, 866 serum samples collected between 1994 and 2002 from harbor seals captured or stranded on the Pacific and Atlantic coasts of North America were assayed by enzyme linked immunosorbent assay (ELISA) for evidence of PhHV-1 exposure. Samples from three harbor seal age classes (pre-weaned, weaned, and subadults/adults) were obtained from each of four regions to compare exposure among sex, age class, and region. We found increasing prevalence with age as 37.5% of pre-weaned pups, 87.6% of weaned pups, and 99.0% of subadults and adults were seropositive. When accounting for age, no associations between seropositivity and sex or location of harbor seals were detected. These data indicate that PhHV-1 is endemic in the harbor seal populations of North America.
Asunto(s)
Anticuerpos Antivirales/sangre , Infecciones por Herpesviridae/veterinaria , Phocidae/virología , Varicellovirus/inmunología , Factores de Edad , Animales , Animales Recién Nacidos , Animales Lactantes , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Infecciones por Herpesviridae/epidemiología , Masculino , América del Norte/epidemiología , Estudios Seroepidemiológicos , Varicellovirus/aislamiento & purificaciónAsunto(s)
Enfermedades de los Bovinos/patología , Meningoencefalitis/veterinaria , Trombosis/veterinaria , Animales , Bovinos , Enfermedades de los Bovinos/líquido cefalorraquídeo , Masculino , Meningoencefalitis/líquido cefalorraquídeo , Meningoencefalitis/patología , Trombosis/líquido cefalorraquídeo , Trombosis/patologíaAsunto(s)
Arritmias Cardíacas/inducido químicamente , Arritmias Cardíacas/veterinaria , Equidae , Nerium/toxicidad , Animales , Antiarrítmicos/uso terapéutico , Arritmias Cardíacas/tratamiento farmacológico , Corazón/efectos de los fármacos , Corazón/fisiopatología , Masculino , Intoxicación por Plantas/fisiopatología , Intoxicación por Plantas/veterinaria , Plantas Tóxicas/toxicidadRESUMEN
To determine the effects of two diets and water supplies on intestinal pH and mineral concentrations in the colon of horses, and to identify whether differences in these parameters exist in horses with and without enterolithiasis, surgical fistulation of the right dorsal colon was performed in six adult horses, three with and three without enterolithiasis. Each horse underwent four feeding trials: grass hay and untreated water, alfalfa hay and untreated water, grass hay with filtered/softened water, and alfalfa hay with filtered/softened water. Samples of colonic contents were analyzed for pH, dry matter, and mineral concentrations. Horses with enterolithiasis had higher calcium, magnesium, phosphorus and sulfur concentrations and higher pH in colonic contents than controls. Horses fed alfalfa had lower colonic sodium and potassium, higher calcium, magnesium, phosphorus and sulfur concentrations, and a more alkaline pH than those fed grass. Grass hay consumption leads to reduced concentrations of select minerals and a more acidic colonic environment compared with alfalfa, probably beneficial in the prevention of enterolithiasis. Under controlled dietary and management conditions, horses with enterolithiasis have differences in colonic mineral and pH parameters that may be consistent with physiological differences between horses with and without the disease.
Asunto(s)
Alimentación Animal/análisis , Colon/química , Enfermedades de los Caballos/prevención & control , Enfermedades Intestinales/veterinaria , Litiasis/veterinaria , Abastecimiento de Agua/análisis , Alimentación Animal/efectos adversos , Animales , Estudios de Casos y Controles , Femenino , Enfermedades de los Caballos/dietoterapia , Enfermedades de los Caballos/etiología , Enfermedades de los Caballos/metabolismo , Caballos , Concentración de Iones de Hidrógeno , Enfermedades Intestinales/etiología , Enfermedades Intestinales/metabolismo , Enfermedades Intestinales/prevención & control , Litiasis/etiología , Litiasis/metabolismo , Litiasis/prevención & control , Compuestos de Magnesio/análisis , Compuestos de Magnesio/metabolismo , Masculino , Minerales/análisis , Minerales/metabolismo , Fosfatos/análisis , Fosfatos/metabolismo , Factores de Riesgo , Estruvita , Abastecimiento de Agua/normasRESUMEN
The Hawaiian monk seal population has experienced precipitous declines in the last 50 years. In this study, we provide evidence that individuals from remaining endangered population exhibit alarming uniformity in class I major histocompatibility (MHC) genes. The peripheral blood leukocyte-derived mRNA of six captive animals rescued from a stranding incident on the French frigate shoals in the Hawaiian archipelago was used to characterize genes in the monk seal class I MHC gene family, from which techniques for genotyping the broader population were designed using degenerate primers designed for the three major established human MHC class I loci (HLA-A, HLA-B, and HLA-C), and by sequencing multiple clones, six unique full-length classical MHC class I gene transcripts were identified among the six animals, three of which were only found in single individuals. Since The low degree of sequence variation between these transcripts and the similarity of genotype between individuals provided preliminary evidence for low class I MHC variability in the population. The sequence information from the class I transcripts from these six animals was used to design several primer sets for examining the extent of MHC variability in the remaining population using a combination of polymerase chain reaction and denaturing gradient gel electrophoresis (DGGE). Several DGGE assays, each one amplifying subtly different class I MHC gene combinations, were designed to compare exons encoding the highly polymorphic domains of the putative peptide-binding region of MHC class I. In combination, these assays failed to show interindividual variability at any of the class I MHC gene loci examined in either the six captive seals or in 80 free-ranging animals ( approximately 6.7% of the estimated population) representing all six major subpopulations of Hawaiian monk seal.
Asunto(s)
Variación Genética , Antígenos de Histocompatibilidad Clase I/clasificación , Antígenos de Histocompatibilidad Clase I/genética , Phocidae/inmunología , Secuencia de Bases , Genotipo , Humanos , Leucocitos/química , Datos de Secuencia Molecular , Filogenia , ARN Mensajero/análisis , ARN Mensajero/genética , Phocidae/genética , Análisis de Secuencia de ADN , Transcripción GenéticaRESUMEN
Epizootic bovine abortion (EBA) is endemic in California's coastal range and the foothill regions of the Sierra Nevada, where it has been the primary diagnosed cause of abortion in beef cattle for >50 years. Investigation of these losses has defined a specific fetal syndrome characterized by late-term abortion or birth of weak or dead calves. Although the unusual clinical presentation and unique fetal pathology associated with EBA have been recognized since the 1950s, the identity of the etiologic agent is unknown. In this study, suppression-hybridization PCR was used to identify a fragment of the 16S rRNA gene of a previously undescribed bacterium in thymus tissue derived from affected fetuses. Phylogenetic analysis revealed that this pathogen was a deltaproteobacterium closely related to members of the order Myxococcales. A specific PCR was subsequently developed to detect the presence of this bacterium in DNA extracted from fetal thymuses. Using histopathology as the definitive diagnosis for EBA, this PCR demonstrated 100% specificity and 88% sensitivity. The bacterium was also detected in the argasid tick Ornithodoros coriaceus, which is the recognized vector of EBA. These data imply a close association between this novel agent and the etiology of EBA.
Asunto(s)
Aborto Veterinario/microbiología , Enfermedades de los Bovinos/microbiología , Deltaproteobacteria/clasificación , Deltaproteobacteria/genética , Infecciones por Bacterias Gramnegativas/veterinaria , Reacción en Cadena de la Polimerasa/métodos , Animales , Vectores Arácnidos/microbiología , Bovinos , Deltaproteobacteria/aislamiento & purificación , Femenino , Enfermedades Fetales/microbiología , Enfermedades Fetales/veterinaria , Infecciones por Bacterias Gramnegativas/microbiología , Datos de Secuencia Molecular , Ornithodoros/microbiología , Embarazo , Complicaciones Infecciosas del Embarazo/microbiología , Complicaciones Infecciosas del Embarazo/veterinaria , Sensibilidad y Especificidad , Síndrome , Timo/microbiologíaRESUMEN
In response to an unprecedented prevalence of cancer recently identified in free-ranging populations of California sea lions [(CSL) (Zalophus californianus], we examined the role of the immunologically important major histocompatibility (MHC) genes in this disease epidemic. Associations between MHC genes and cancer have been well established in humans, but have never before been investigated in wildlife. Using a previously developed technique employing sequence-specific primer-based PCR with intercalating dye technology, MHC genotypes were examined from 27 cancer-positive and 22 cancer-negative CSL stranded along the California coastline. Analyses elucidated an underlying immunogenetic component to the high prevalence of urogenital cancer in sea lions. Furthermore, these results demonstrate the functional relevance of CSL class II MHC by revealing a non-random nature of cancer susceptibility associated with the presence of specific genes.
Asunto(s)
Predisposición Genética a la Enfermedad , Leones Marinos/genética , Leones Marinos/inmunología , Neoplasias Urogenitales/genética , Neoplasias Urogenitales/inmunología , Animales , Genotipo , Complejo Mayor de HistocompatibilidadRESUMEN
Equine malignant hyperthermia MH has been suspected but never genetically confirmed. In this study, we investigated whether mutations in a candidate gene, RyR1, were associated with MH in two clinically affected horses. RyR1 gene sequences revealed polymorphisms in exons 15, 17, and 46 in WTRyR1 and MHRyR1 horses with one derived amino acid change in MHRyR1 exon 46, R2454G. The MHRyR1 horses were genetically heterozygous for this mutation, but presented an MH phenotype with halothane challenge. Skeletal sarcoplasmic reticulum from a R2454G heterozygote collected during a fulminant MH episode showed significantly higher affinity and density of [3H]ryanodine-binding sites compared to WTRyR1, but no differences in Ca2+, Mg2+, and caffeine modulation. In conclusion, an autosomal missense mutation in RyR1 is associated with MH in the horse, providing a screening test for susceptible individuals. [3H]ryanodine-binding analysis suggests that long-lasting changes in RyR1 conformation persists in vitro after the triggering event.
Asunto(s)
Enfermedades de los Caballos/genética , Hipertermia Maligna/genética , Hipertermia Maligna/veterinaria , Mutación , Canal Liberador de Calcio Receptor de Rianodina/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Histocitoquímica , Enfermedades de los Caballos/metabolismo , Caballos , Hipertermia Maligna/metabolismo , Datos de Secuencia Molecular , Músculo Esquelético/metabolismo , Unión Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/metabolismoRESUMEN
Petroleum oil enters the coastal marine environment through various sources; marine mammals such as sea otters that inhabit this environment may be exposed to low concentrations of petroleum hydrocarbons through ingestion of contaminated prey. The inability to perform controlled studies in free-ranging animals hinders investigations of the effects of chronic petroleum oil exposure on sea otter morbidity and mortality, necessitating the development of a reliable laboratory model. We examined the effects of oral exposure to 500 ppm bunker C fuel oil over 113-118 days on American mink, a species phylogenetically related to the sea otter. Hematological parameters and organs were examined for fuel oil-associated changes. Hepatic cytochrome P4501A1 mRNA expression and fecal cortisol concentrations were also measured. Ingestion of fuel oil was associated with a decrease in erythrocyte count, hemoglobin concentration (Hgb), hematocrit (HCT), and an increase in mean corpuscular volume (MCV). Total leukocytes were elevated in the fuel oil group from increases in neutrophils, lymphocytes, and monocytes. Significant interactions between fuel oil and antigen challenge were found for erythrocyte parameters, monocyte and lymphocyte counts. Liver and adrenal weights were increased although mesenteric lymph node weights were decreased in the fuel oil group. Hepatic cytochrome P4501A1 mRNA was elevated in the fuel oil group. Fecal cortisol concentration did not vary between the two groups. Our findings show that fuel oil exposure alters circulating leukocyte numbers, erythrocyte homeostasis, hepatic metabolism and adrenal physiology and establish a framework to use mink as a model for sea otters in studying the systemic effects of marine contaminants.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Aceites Combustibles/toxicidad , Visón/metabolismo , Contaminantes Químicos del Agua/toxicidad , Animales , Citocromo P-450 CYP1A1/biosíntesis , Citocromo P-450 CYP1A1/genética , Dinitrobencenos/metabolismo , Recuento de Eritrocitos , Heces/química , Hemoglobinas/metabolismo , Histocitoquímica , Hidrocortisona/metabolismo , Recuento de Leucocitos , Hepatopatías/sangre , Hepatopatías/metabolismo , Masculino , Visón/sangre , Modelos Animales , Tamaño de los Órganos/efectos de los fármacos , Nutrias/sangre , Nutrias/metabolismo , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Distribución Aleatoria , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
In light of the immunological importance of molecules encoded within the major histocompatibility complex ( MHC), there are numerous studies examining the variability of these genes in wildlife populations. An underlying assumption in many of these studies is that MHC diversity invariably arises from a high level of allelic variation at a single gene locus, leading to widespread descriptions of thriving species with apparently limited MHC polymorphism. Indeed, in a previous study we failed to find sequence features compatible with traditionally diverse peptide-binding functions in MHC class II ( DQA and DQB) genes in California sea lions and therefore expanded the search for polymorphism to the DRA and DRB genes. Our results show that, in contrast to Zaca-DQA, -DQB, and - DRA, Zaca-DRB has sequence features compatible with antigen binding and presentation. In fact Zaca-DRB constitutes a gene family, comprising at least seven loci, each of which exhibits limited variability, and which are present in variable configurations between individuals. This unusual mechanism for generating MHC DRB diversity is similar to that observed in the rhesus macaque, but has not been reported in any other species. The identification of a novel system of class II MHC variability in the California sea lion justifies new studies into the organizational basis of immunogenetic diversity in other marine species, and its role in infectious disease susceptibility.
Asunto(s)
Genes MHC Clase II , Polimorfismo Genético , Leones Marinos/genética , Leones Marinos/inmunología , Animales , Secuencia de Bases , California , Clonación Molecular , ADN Complementario/genética , Exones , Variación Genética , Datos de Secuencia Molecular , Filogenia , Polimorfismo Conformacional Retorcido-Simple , Homología de Secuencia de Ácido NucleicoRESUMEN
To date, there are no published MHC sequences from the California sea lion (Zalophus californianus), a thriving species that, by feeding high on the marine food web, could be a sentinel for disturbances in marine and coastal ecosystems. In this study, degenerate primers and RACE technology were used to amplify near-full-length (MhcZaca- DQB) and full-length (MhcZaca- DQA) expressed class II MHC gene products from the peripheral blood mononuclear cells of two California sea lions in rehabilitation. Five unique Zaca- DQA sequences and eight unique Zaca- DQB sequences, all encoding functional proteins, were identified in the two animals, indicating the presence of multiple DQ- loci in this species. An additional three Zaca- DQB sequences containing features compatible with pseudogenes or null alleles were also identified. Despite the identification of multiple DQA and DQB sequences, the degree of heterogeneity between them was extremely low. To confirm the limited degree of Zaca-DQ nucleotide variation between individuals, we used denaturing gradient gel electrophoresis to examine putative peptide binding region sequences from the peripheral blood leukocyte-derived RNAs of 19 wild-caught California sea lions from physically distinct populations. The pattern of Zaca-DQ sequence migration was identical between individuals and independent of geographical region. This apparent Zaca-DQ sequence identity between sea lions was confirmed by direct sequencing of individual bands. In combination, these findings raise important questions regarding immunogenetic diversity within this thriving species, and should prompt further research into the existence of a highly polymorphic sea lion class II MHC molecule with sequence features that support traditional peptide binding functions.