Zoonotic pathogens from feral swine that pose a significant threat to public health.

The natural fecundity of suids, great ability to adapt to new habitats and desire for local hunting opportunities leading to translocation of feral pigs to regions where they are not yet established have all been instrumental in the home range expansion of feral swine. Feral swine populations in the United States continue to expand, wreaking havoc on agricultural lands, further compromising threatened and endangered species, and posing a microbiological threat to humans, domestic livestock and companion animals. This manuscript thoroughly reviews zoonotic diseases of concern including brucellosis, bovine tuberculosis, leptospirosis, enteric pathogens, both Salmonella spp. and shiga toxin-producing Escherichia coli, and hepatitis E. These pathogens are not a comprehensive list of microbes that are capable of infecting both humans and feral swine, but rather have been selected as they are known to infect US feral swine, direct transmission between wild suids and humans has previously been documented, or they have been shown to be readily transmitted during processing or consumption of feral swine pork. Humans that interact directly or indirectly with feral swine are at much higher risk for the development of a number of zoonotic pathogens. Numerous case reports document transmission events from feral swine and wild boar to humans, and the resulting diseases may be mild and self-limiting, chronic or fatal. Individuals that interact with feral swine should take preventative measures to minimize the risk of disease transmission and all meat should be thoroughly cooked. Additionally, public health campaigns to increase knowledge of the risks associated with feral swine are imperative.

Serosurveillance and factors associated with the presence of antibodies against bluetongue virus in dairy cattle in two eco-zones of Nepal.

Cattle play an important role in the epidemiology of bluetongue (BT) by acting as reservoir hosts. However, the status of BT virus (BTV) in dairy cattle in Nepal is unknown. The objective of this study was to estimate the prevalence of BTV antibodies in dairy cattle in two eco-zones of Nepal, and to identify the factors associated with virus exposure. The authors conducted a cross-sectional serosurvey from March 2012 through February 2013 by sampling 131 dairy cattle from seven clusters (villages) in the Chitwan district in the Terai region (southern lowlands) and the Lamjung district in the Hills region (the middle part of Nepal). Of the 131 serum samples tested, 29.3% (95% confidence interval [CI]: 21.5-37.2) were positive for BTV antibodies. Herd-level seroprevalence was 45.7% (95% CI: 30.9-61.0). Bivariate analysis indicated a positive association between seroconversion to BTV and age, and an association with breed of cattle after controlling for clustering of animals within herds. Based on this model, cattle were more likely to become seropositive as they aged. Crossbred cattle were more likely to be seropositive than those of exotic breeds (odds ratio [OR] = 4.6; 95% CI: 1.5-14.1). The results indicate widespread exposure of dairy cattle to BTV in Nepal. The authors suggest that dairy cattle should be included in the surveillance plan for BTV infection in Nepal and that it is important to educate farmers about the possible impacts of this disease.

Les bovins jouent un rôle important en tant qu'hôtes réservoirs dans l'épidémiologie de la fièvre catarrhale ovine (FCO). Toutefois, au Népal le statut des bovins de races laitières au regard du virus de la FCO était inconnu. La présente étude a été conduite pour estimer la prévalence des anticorps dirigés contre la FCO chez les bovins laitiers dans deux zones écologiques du Népal et pour élucider les facteurs présentant un lien avec l'exposition virale. Les auteurs ont réalisé une enquête sérologique transversale de mars 2012 à février 2013, en prélevant 131 bovins laitiers répartis en sept groupes (villages) du district de Chitwan, région de Terai (plaines méridionales) et du district de Lamjung, région des Collines (centre du Népal). La présence d'anticorps dirigés contre la FCO a été détectée dans 29,3 % des 131 sérums testés (intervalle de confiance [IC] à 95 % : 21,5­37,2). À l'échelle des troupeaux, la prévalence sérologique était de 45,7 % (IC à 95 % : 30,9­61,0). L'analyse bivariée a fait apparaître une corrélation positive entre l'apparition d'anticorps dirigés contre la FCO et l'âge et, après vérification de la répartition des bovins par groupes au sein des troupeaux, une corrélation avec la race. D'après ce modèle, l'apparition d'anticorps devenait plus fréquente à mesure que les bovins prenaient de l'âge. De même, l'apparition d'anticorps était plus fréquente chez les bovins de races croisées que chez les bovins de race exotique (rapport de cotes = 4,6 ; IC à 95 % : 1,5­14,1). Ces résultats font état de l'ampleur de l'exposition des bovins laitiers au virus de la FCO au Népal. Les auteurs préconisent d'intégrer les bovins de races laitières dans le plan de surveillance de l'infection par le virus de la FCO au Népal et de sensibiliser les éleveurs sur les conséquences potentielles de cette maladie.

El ganado vacuno cumple una importante función en la epidemiología de la lengua azul por su intervención como hospedador reservorio. Pese a ello, en el Nepal se desconoce cuál es el estado del ganado lechero en relación con el virus de la enfermedad. Los autores describen un estudio destinado a estimar la prevalencia de anticuerpos contra el virus de la lengua azul en el ganado lechero de dos zonas ecológicas del Nepal y a determinar los factores asociados a la exposición al virus. En primer lugar, entre marzo de 2012 y febrero de 2013, se llevó a cabo un estudio serológico transversal con la obtención de muestras de 131 bovinos lecheros de siete agrupaciones (aldeas) de los distritos de Chitwan, región de Terai (vegas meridionales), y de Lamjung, región de las Colinas (en la zona central del país). De las 131 muestras de suero analizadas, resultaron positivas para los anticuerpos contra el virus de la lengua azul el 29,3% (intervalo de confianza [IC] al 95%: 21,5­37,2). La seroprevalencia de rebaño se cifraba en un 45,7% (IC 95%: 30,9­61,0). El análisis de dos variables puso de manifiesto una correlación positiva entre la seroconversión contra el virus de la lengua azul y la edad, así como una asociación con la raza del ganado, previo control de las agrupaciones de animales dentro de los rebaños. Según se desprende de este modelo, la probabilidad de que el ganado pase a ser positivo aumenta con la edad. Los animales de raza híbrida presentan mayor probabilidad de ser seropositivos que los de razas exóticas (razón de probabilidades = 4,6; IC 95%: 1,5­14,1). Estos resultados ponen de relieve una extendida exposición al virus en el ganado lechero nepalí. Los autores preconizan la inclusión del ganado vacuno lechero en el plan de vigilancia de la infección por el virus de la lengua azul en el Nepal y recalcan la importancia de hacer pedagogía entre los ganaderos acerca de las posibles repercusiones de la enfermedad.

West Nile viral infection of equids.

West Nile virus (WNV) is a flavivirus transmitted between certain species of birds and mosquito vectors. Tangential infections of equids and subsequent equine epizootics have occurred historically. Although the attack rate has been estimated to be below 10%, mortality rates can approach 50% in horses that present clinical disease. Symptoms are most commonly presenting in the form of encephalitis with ataxia as well as limb weakness, recumbency and muscle fasciculation. The most effective strategy for prevention of equine disease is proper vaccination with one of the numerous commercially available vaccines available in North America or the European Union. Recently, WNV has been increasingly associated with equine epizootics resulting from novel non-lineage-1a viruses in expanding geographic areas. However, specific experimental data on the virulence of these novel virus strains is lacking and questions remain as to the etiology of the expanded epizootics: whether it be a function of inherent virulence or ecological and/or climactic factors that could precipitate the altered epidemiological patterns observed.

Ecology of zoonotic infectious diseases in bats: current knowledge and future directions.

Bats are hosts to a range of zoonotic and potentially zoonotic pathogens. Human activities that increase exposure to bats will likely increase the opportunity for infections to spill over in the future. Ecological drivers of pathogen spillover and emergence in novel hosts, including humans, involve a complex mixture of processes, and understanding these complexities may aid in predicting spillover. In particular, only once the pathogen and host ecologies are known can the impacts of anthropogenic changes be fully appreciated. Cross-disciplinary approaches are required to understand how host and pathogen ecology interact. Bats differ from other sylvatic disease reservoirs because of their unique and diverse lifestyles, including their ability to fly, often highly gregarious social structures, long lifespans and low fecundity rates. We highlight how these traits may affect infection dynamics and how both host and pathogen traits may interact to affect infection dynamics. We identify key questions relating to the ecology of infectious diseases in bats and propose that a combination of field and laboratory studies are needed to create data-driven mechanistic models to elucidate those aspects of bat ecology that are most critical to the dynamics of emerging bat viruses. If commonalities can be found, then predicting the dynamics of newly emerging diseases may be possible. This modelling approach will be particularly important in scenarios when population surveillance data are unavailable and when it is unclear which aspects of host ecology are driving infection dynamics.

Use of sindbis/eastern equine encephalitis chimeric viruses in plaque reduction neutralization tests for arboviral disease diagnostics.

Eastern equine encephalitis virus (EEEV) is a highly virulent, mosquito-borne alphavirus that causes severe and often fatal neurological disease in humans and horses in eastern North American, the Caribbean, and Mexico and throughout Central and South America. EEEV infection is diagnosed serologically by anti-EEEV-specific IgM detection, with confirmation by the plaque reduction neutralization test (PRNT), which is highly specific for alphaviruses. Live virus is used in the PRNT procedure, which currently requires biosafety level 3 containment facilities and select agent security in the case of EEEV. These requirements restrict the ability of public health laboratories to conduct PRNTs. Sindbis virus (SINV)/EEEV recombinant constructs have been engineered to express the immunogenic structural proteins from 2 wild-type EEEV strains in an attenuated form. These SINV/EEEVs, which are not classified as select agents, were evaluated as alternative diagnostic reagents in a PRNT using human, equine, and murine sera. The results indicate that the chimeric viruses exhibit specificity comparable to that of wild-type EEEV, with only a slight reduction in sensitivity. Considering their benefits in increased safety and reduced regulatory requirements, these chimeric viruses should be highly useful in diagnostic laboratories throughout the Americas.

Clinical and pathologic responses of American crows (Corvus brachyrhynchos) and fish crows (C ossifragus) to experimental West Nile virus infection.

West Nile virus (WNV)-associated disease has a range of clinical manifestations among avian taxa, the reasons for which are not known. Species susceptibility varies within the avian family Corvidae, with estimated mortality rates ranging from 50 to 100%. We examined and compared virologic, immunologic, pathologic, and clinical responses in 2 corvid species, the American crow (Corvus brachyrhynchos) and the fish crow (C ossifragus), following experimental WNV inoculation. Unlike fish crows, which remained clinically normal throughout the study, American crows succumbed to WNV infection subsequent to dehydration, electrolyte and pH imbalances, and delayed or depressed humoral immune responses concurrent with marked, widespread virus replication. Viral titers were approximately 3,000 times greater in blood and 30,000 to 50,000 times greater in other tissues (eg, pancreas and small intestine) in American crows versus fish crows. Histologic lesion patterns and antigen deposition supported the differing clinical outcomes, with greater severity and distribution of lesions and WNV antigen in American crows. Both crow species had multiorgan necrosis and inflammation, although lesions were more frequent, severe, and widespread in American crows, in which the most commonly affected tissues were small intestine, spleen, and liver. American crows also had inflammation of vessels and nerves in multiple tissues, including heart, kidney, and the gastrointestinal tract. WNV antigen was most commonly observed within monocytes, macrophages, and other cells of the reticuloendothelial system of affected tissues. Collectively, the data support that WNV-infected American crows experience uncontrolled systemic infection leading to multiorgan failure and rapid death.

Male contraceptive technology for nonhuman male mammals.

Contraceptive techniques applied to males have potential to mitigate diverse instances of overpopulation in human and animal populations. Different situations involving different species dictate that there is no ideal male contraceptive, and emphasizes the value of varying approaches to reducing male fertility. A majority of work in this field has focused on non-surgically destroying the testes or obstructing the epididymis, and suppressing gonadotropin secretion or inducing immune responses to reproductive hormones or sperm-specific antigens. Injection of tissue-destructive agents into the testes or epididymides can be very effective, but often is associated with unacceptable inflammatory responses and sometimes pain. Hormonal vaccines are often not efficacious and provide only short-term contraception, although GnRH vaccines may be an exception to this generality. Finally, there are no clearly effective contraceptive vaccines based on sperm antigens. Although several techniques have been developed to the point of commercialization, none has yet been widely deployed other than surgical castration.

Efficacy, duration, and onset of immunogenicity of a West Nile virus vaccine, live Flavivirus chimera, in horses with a clinical disease challenge model.

REASON FOR PERFORMING STUDY: West Nile virus (WNF) is a Flavivirus responsible for a life-threatening neurological disease in man and horses. Development of improved vaccines against Flavivirus infections is therefore important. OBJECTIVES: To establish that a single immunogenicity dose of live Flavivirus chimera (WN-FV) vaccine protects horses from the disease and it induces a protective immune response, and to determine the duration of the protective immunity. METHODS: Clinical signs were compared between vaccinated (VACC) and control (CTRL) horses after an intrathecal WNV challenge given at 10 or 28 days, or 12 months post vaccination. RESULTS: Challenge of horses in the immunogenicity study at Day 28 post vaccination resulted in severe clinical signs of WNV infection in 10/10 control (CTRL) compared to 1/20 vaccinated (VACC) horses (P<0.01). None of the VACC horses developed viraemia and minimal histopathology was noted. Duration of immunity (DPI) was established at 12 months post vaccination. Eight of 10 CTRL exhibited severe clinical signs of infection compared to 1 of 9 VACC horses (P<0.05). There was a significant reduction in the occurrence of viraemia and histopathology lesion in VACC horses relative to CTRL horses. Horses challenged at Day 10 post vaccination experienced moderate or severe clinical signs of WNV infection in 3/3 CTRL compared to 5/6 VACC horses (P<0.05). CONCLUSIONS: This novel WN-FV chimera vaccine generates a protective immune response to WNV infection in horses that is demonstrated 10 days after a single vaccination and lasts for up to one year. POTENTIAL RELEVANCE: This is the first USDA licensed equine WNV vaccine to utilise a severe challenge model that produces the same WNV disease observed under field conditions to obtain a label claim for prevention of viraemia and aid in the prevention of WNV disease and encephalitis with a duration of immunity of 12 months.

Comparative efficacies of three commercially available vaccines against West Nile Virus (WNV) in a short-duration challenge trial involving an equine WNV encephalitis model.

We used a severe challenge model that produces clinical West Nile virus (WNV) disease to test the efficacy of three commercially available equine WNV vaccines in horses. Twenty-four healthy, WNV-seronegative horses of varying ages and genders were placed, in random and blind manner, into three trial groups consisting of eight horses each; two horses in each group received (i) an inactivated WNV vaccine (K-WN), (ii) a modified-live vaccine (CP-WN) containing the WNV prM and E proteins expressed by a canarypox vector, (iii) a live-chimera vaccine (WN-FV) containing WNV prM and E proteins expressed in a YF17D vector, or (iv) a diluent control. Challenge by this model caused grave neurological signs, viremia, moderate to severe histopathologic lesions in the brain and spinal cord, and an outcome of 0% survivorship in all six control horses. In contrast, challenge in horses at between 28 days postvaccination with the chimera vaccine and 56 days postvaccination with the commercial inactivated or modified-live vaccine resulted in 100% survivorship (protection from the onset of WNV encephalitis and viremia). Horses vaccinated with the live-chimera vaccine showed significantly fewer clinical signs than did the control horses (P

Experimental infection of pigs with West Nile virus.

Young adult and weanling pigs were challenged with the New York 99 strain of West Nile virus through the bite of infected mosquitoes. Each of six adult pigs seroconverted, but virus was isolated from serum of only one pig following challenge. Three of five weanling pigs developed viremia, with peak titers of 10(1.9) and 10(3.1) PFU/mL. Clinical signs attributable to West Nile virus infection were not observed in any of these animals. An additional four pigs were challenged by feeding West Nile virus-infected mice, and none of the four developed a detectable viremia or seroconverted. These results suggest that pigs are unlikely to play a significant role as amplifying hosts of West Nile virus.

Virulence and viremia characteristics of 1992 epizootic subtype IC Venezuelan equine encephalitis viruses and closely related enzootic subtype ID strains.

Following a 19-year hiatus, Venezuelan equine encephalitis (VEE) reemerged in western Venezuela in December 1992. This outbreak is important in understanding VEE emergence because phylogenetic studies imply that sympatric, enzootic, subtype ID VEE viruses mutated to generate the epizootic/epidemic. Although the 1992-1993 strains belong to subtype IC, a serotype implicated in extensive outbreaks during the 1960s and in 1995, relatively small numbers of human and equine cases occurred in 1992-1993. We, therefore, evaluated the pathogenicity of these Venezuelan enzootic ID and epizootic IC viruses to determine 1) if they exhibit phenotypes like those described previously for more distantly related enzootic and epizootic strains, and 2) if the 1992-1993 outbreak was limited by the inability of these IC viruses to exploit equines as amplification hosts. All strains were virulent in mice and guinea pigs, but were benign for cotton rats, natural hosts of enzootic viruses. However, only the IC strains produced equine disease, with mean peak viremias of 10(5) suckling mouse 50% lethal doses per mL serum, and some titers exceeding 10(7). These viremias approximate those observed previously with VEE strains isolated during more extensive epizootics, suggesting that efficient equine amplification did not limit the scope and duration of the 1992-1993 outbreak. Enzootic ID virus infection protected all horses from challenge with epizootic strain P676, supporting the hypothesis that epizootics bypass regions of enzootic transmission due to natural immunization of equines by enzootic VEE viruses.

Response to and efficacy of vaccination against eastern equine encephalomyelitis virus in emus.

OBJECTIVE: To evaluate humoral immune responses of emus vaccinated with commercially available equine polyvalent or experimental monovalent eastern equine encephalomyelitis (EEE) virus and western equine encephalomyelitis (WEE) virus vaccines and to determine whether vaccinated emus were protected against challenge with EEE virus. DESIGN: Cohort study. ANIMALS: 25 emus. PROCEDURE: Birds were randomly assigned to groups (n = 5/group) and vaccinated with 1 of 2 commercially available polyvalent equine vaccines, a monovalent EEE virus vaccine, or a monovalent WEE virus vaccine or were not vaccinated. Neutralizing antibody responses against EEE and WEE viruses were examined at regular intervals for up to 9 months. All emus vaccinated with the equine vaccines and 2 unvaccinated control birds were challenged with EEE virus. An additional unvaccinated bird was housed with the control birds to assess the possibility of contact transmission. RESULTS: All 4 vaccines induced detectable neutralizing antibody titers, and all birds vaccinated with the equine vaccines were fully protected against an otherwise lethal dose of EEE virus. Unvaccinated challenged birds developed viremia (> 10(9) plaque-forming units/ml of blood) and shed virus in feces, oral secretions, and regurgitated material. The unvaccinated pen-mate became infected in the absence of mosquito vectors, presumably as a result of direct virus transmission between birds. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that emus infected with EEE virus develop a high-titer viremia and suggest that they may serve as important virus reservoirs. Infected emus shed EEE virus in secretions and excretions, making them a direct hazard to pen-mates and attending humans. Commercially available polyvalent equine vaccines protect emus against EEE virus infection.

Expression of human MxA protein in mosquito cells interferes with LaCrosse virus replication.

Human MxA protein inhibits LaCrosse virus (LAC virus; family Bunyaviridae) replication in vertebrate cells and MxA-transgenic mice. LAC virus is transmitted to humans by Aedes triseriatus mosquitoes. In this report, we have shown that transfected mosquito cells expressing the human MxA cDNA are resistant to LAC virus but permissive for Sindbis virus (family Togaviridae) infection.

High dietary 18:3n-3 increases the 18:3n-3 but not the 22:6n-3 content in the whole body, brain, skin, epididymal fat pads, and muscles of suckling rat pups.

The objective of this study was to test the hypothesis that increasing maternal dietary 18:3n-3 by decreasing the 18:2n-6/18:3n-3 ratio will increase the 18:3n-3 and 22:6n-3 content of the whole body, liver, skin (epidermis, dermis, and subcutaneous tissue), epididymal fat pads, and muscles (arms and legs) of 2-wk-old rat pups. Sprague-Dawley dams at parturition were fed semipurified diets containing either a low (18:2n-6 to 18:3n-3 ratio of 24.7:1) or a high (1 8:2n-6 to 18:3n-3 ratio of 1.0:1) 18:3n-3 fatty acid content. During the first 2 wk of life, rat pups received only their dams' milk. Fatty acid composition of the pups' stomach contents (dams' milk), whole body, brain, liver, skin, epididymal fat pads, and muscles was determined. The stomach fatty acid composition of 18:3n-3 reflected the dams' diet. The content of 18:3n-3 in whole body, brain, liver, skin, epididymal fat pads, and muscles was significantly (P< 0.05) greater in rat pups fed the high compared with the low 18:3n-3 fatty acid diet. The 22:6n-3 content of the whole body, brain, skin, epididymal fat pads, and muscles was not quantitatively different in rat pups fed either the low or high 18:3n-3 fatty acid diet. The 20:5n-3 and 22:5n-3 content of the whole body, skin, and epididymal fat pads was significantly increased in rat pups fed the high compared with the low 18:3n-3 fatty acid diet. High content of 18:3n-3 was found in the skin of rat pups fed either a low or high 18:3n-3 fatty acid diet. These findings demonstrate that high maternal dietary 18:3n-3 significantly increases the 18:3n-3 but not the 22:6n-3 content of the whole body, brain, skin, epididymal fat pads, and muscles with approximately 39 and 41% of the whole body 18:3n-3 content being deposited in the skin of suckling rat pups fed either the low or high 18:3n-3 diet, respectively.

Immune responses in mice, cattle and horses to a DNA vaccine for vesicular stomatitis.

Vesicular stomatitis (VS) virus causes an important clinical disease of cattle and horses in North America. In order for a vaccine to be useful in the control of VS, it must not only protect against disease, but allow ready differentiation of infected and vaccinated animals. In these studies, we evaluated neutralizing antibody responses in outbred mice, calves, and horses that received a DNA vaccine that expressed the glycoprotein (G) gene of VS New Jersey virus. The vaccine elicited antibody titers in individuals from each species, especially when two doses were administered, but the level of neutralizing antibody needed to confer protection is not known. In mice, co-administration of a plasmid that expressed interleukin-2 resulted in a significant, though modest, increase in antibody titers relative to use of the G gene vaccine alone. The effect of co-injecting putative immunostimulatory oligonucleotides was also evaluated. This treatment had no apparent effect in horses and was found to suppress immune responses to the G gene vaccine in mice. If the immune responses obtained in these studies prove to protect cattle and horses from infection with VS virus, DNA vaccination may become a useful tool for control of this disease.

In vivo transfection and expression of exogenous genes within proximal tubules of rats.

An in vivo technique for expressing exogenous DNA within the renal cortical proximal tubules of rats was was developed and validated. Cationic liposomes were complexed with either water or 25 microg of plasmid DNA containing the lac Z gene, and injected into the left renal artery of anesthetized rats. Under transcriptional control of the chicken beta-actin, SV40, and CMV promoters, beta-galactosidase expression was consistently observed in rats that received plasmid DNA, while no blue staining was observed in kidneys of control rats. Using an injection volume of 400 microl, lac Z expression was confined to the proximal tubules, with no lac Z expression noted within serial sections of the liver, adrenal, lung, spleen, or heart. Because lac Z expression was observed for up to 20 days without apparent systemic or renal insult, this technique may be a valuable tool for evaluating physiological and pathophysiological changes associated with gene expression within this isolated site.

Does increasing dietary linolenic acid content increase the docosahexaenoic acid content of phospholipids in neuronal cells of neonatal rats?

The objective of this study was to investigate if increasing maternal dietary linolenic acid (18:3n-3) content, by decreasing the 18:2n-6 to 18:3n-3 ratio, could increase the docosahexaenoic acid (22:6n-3) content in phospholipids of neuronal cells of rat pups at 2 weeks of age. Sprague-Dawley dams at parturition were fed semipurified diets containing decreasing ratios of 18:2n-6 to 18:3n-3 from 21.6:1 to 1:1. During the first 2 weeks of life, the rat pups received only their dam's milk. The fatty acid composition of the pups stomach contents (dam's milk) and the phospholipids from neuronal cells were identified and quantitated by gas-liquid chromatography. The stomach 22:6n-3 content analyzed from the rat pups at 2 weeks of age was altered by the maternal diet. Fatty acid analysis of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS) in neuronal cells of the rat pups showed no significant increase in 22:6n-3 content with increasing 18:3n-3 in the maternal diet (p > 0.05). In contrast, the content of 22:6n-3 in phosphatidylinositol (PI) was significantly increased by change in dietary 18:3n-3 intake from a dietary 18:2n-6 to 18:3n-3 ratio of 7.8:1 to 4.4:1. It is concluded that increasing maternal dietary 18:3n-3 by decreasing the 18:2n-6 to 18:3n-3 ratio does not significantly increase the 22:6n-3 content in PC, PE, and PS in neuronal cells of rat pups at 2 weeks of age.

Cloning and characterization of cDNAs for a bovine (Bos taurus) Mx protein.

Mx proteins are GTPases that are stringently induced in cells from many vertebrates on exposure to type I interferons (IFNs), and expression of some Mx proteins potently inhibits replication of specific viruses. Two cDNAs encoding bovine Mx proteins were isolated from an endometrial phage library. The open reading frames (ORFs) of these two clones predict proteins of 654 (Mxl) and 648 (Mxl-a) residues. Both possess the tripartite GTPase domains, dynamin signature, and leucine zipper motifs conserved in all other Mx proteins identified. The bovine protein sequences show highest identity to ovine Mx (93%) and are substantially similar to human MxA (73%) and mouse Mx1 (63%). Based on differences between the two bovine clones in the coding and 3'-untranslated regions, it was concluded that they represent two alleles of one gene, and heterozygous and homozygous cattle were identified. Expression of Mx mRNA was rapidly induced in cultured bovine cells by treatment with IFN.