Colombian Creole horse breeds: Same origin but different diversity

In order to understand the genetic ancestry and mitochondrial DNA (mtDNA) diversity of current Colombian horse breeds we sequenced a 364-bp fragment of the mitocondrial DNA D-loop in 116 animals belonging to five Spanish horse breeds and the Colombian Paso Fino and Colombian Creole cattle horse breeds. Among Colombian horse breeds, haplogroup D had the highest frequency (53%), followed by haplogroups A (19%), C (8%) and F (6%). The higher frequency of haplogroup D in Colombian horse breeds supports the theory of an ancestral Iberian origin for these breeds. These results also indicate that different selective pressures among the Colombian breeds could explain the relatively higher genetic diversity found in the Colombian Creole cattle horse when compared with the Colombian Paso Fino.     

The distribution pattern of Lutzomyia longipalpis (Diptera: Psychodidae) in the peridomiciles of a sector with canine and human visceral leishmaniasis transmission in the municipality of Dracena, São Paulo, Brazil

The specimen distribution pattern of a species can be used to characterise a population of interest and also provides area-specific guidance for pest management and control. In the municipality of Dracena, in the state of S?o Paulo, we analysed 5,889 Lutzomyia longipalpis specimens collected from the peridomiciles of 14 houses in a sector where American visceral leishmaniasis (AVL) is transmitted to humans and dogs. The goal was to analyse the dispersion and a theoretical fitting of the species occurrence probability. From January-December 2005, samples were collected once per week using CDC light traps that operated for 12-h periods. Each collection was considered a sub-sample and was evaluated monthly. The standardised Morisita index was used as a measure of dispersion. Adherence tests were performed for the log-series distribution. The number of traps was used to adjust the octave plots. The quantity of Lu. longipalpis in the sector was highly aggregated for each month of the year, adhering to a log-series distribution for 11 of the 12 months analysed. A sex-stratified analysis demonstrated a pattern of aggregated dispersion adjusted for each month of the year. The classes and frequencies of the traps in octaves can be employed as indicators for entomological surveillance and AVL control.     

Towards a species level tree of the globally diverse genus Chenopodium (Chenopodiaceae)

Chenopodium is a large and morphologically variable genus of annual and perennial herbs with an almost global distribution. All subgenera and most sections of Chenopodium were sampled along with other genera of Chenopodieae, Atripliceae and Axyrideae across the subfamily Chenopodioideae (Chenopodiaceae), totalling to 140 taxa. Using Maximum parsimony and Bayesian analyses of the non-coding trnL-F (cpDNA) and nuclear ITS regions, we provide a comprehensive picture of relationships of Chenopodium sensu lato. The genus as broadly classified is highly paraphyletic within Chenopodioideae, consisting of five major clades. Compared to previous studies, the tribe Dysphanieae with three genera Dysphania, Teloxys and Suckleya (comprising the aromatic species of Chenopodium s.l.) is now shown to form one of the early branches in the tree of Chenopodioideae. We further recognize the tribe Spinacieae to include Spinacia, several species of Chenopodium, and the genera Monolepis and Scleroblitum. The Chenopodium rubrum and the Ch. murale-clades were newly discovered as distinct major lineages but their relationships within Chenopodioideae will need further evaluation. Based on our results, we suggest the delimitation of Chenopodium to include Einadia and Rhagodia because these are part of the crown group composed of species of subg. Chenopodium that appear sister to the Atripliceae. The tetraploid crops such as Ch. berlandieri subsp. nuttalliae and Ch. quinoa also belong to Chenopodium sensu stricto. Trees derived from trnL-F and ITS were incongruent within this shallow crown group clade. Possible biological causes are discussed, including allopolyploidization.     

Salmonella Typhimurium methionine sulfoxide reductase A (MsrA) prefers TrxA in repairing methionine sulfoxide

Intraphagocytic survival of Salmonella Typhimurium (ST) depends (at least in part) upon its ability to repair oxidant-damaged macromolecules. Met residues either free or in protein bound form are highly susceptible to phagocyte-generated oxidants. Oxidation of Mets leads to Met-SO formation, consequently loss of protein functions that results in cell death. Methionine sulfoxide reductase (Msr) reductively repairs Met-SO to Met in the presence of thioredoxin (trx) and thioredoxin reductase (trxR). Earlier we reported that methionine sulfoxide reductase A (msrA) gene deletion strain of ST suffered oxidative stress.^[1 Trivedi, R.N.; Agarwal, P.; Kumawat, M.; Pesingi, P.K.; Gupta, V.K.; Goswami, T.K.; Mahawar, M. Methionine Sulfoxide Reductase A (MsrA) Contributes to Salmonella Typhimurium Survival Against Oxidative Attack of Neutrophils. Immunobiology 2015, 220(12), 1322–1327.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]^] Thioredoxin system of ST comprises of two thioredoxins (trxA and trxC) and one thioredoxin reductase (trxB). Preferred trx utilized in MsrA-mediated repair of Met-SO is not known. In current study, we cloned, expressed, and purified ST TrxA, TrxB, TrxC, and MsrA in recombinant forms. The migration of TrxA, TrxB, TrxC, and MsrA proteins was approximately 10, 36, 16, and 26?kDa on SDS-gels. The nicotinamide adenine dinucleotide phosphate hydrogen (NADPH)-linked reductase assays interpreted that MsrA utilized two times more NADPH for the reduction of S-methyl p-tolyl sulfoxide when TrxA was included in the assays as compared to TrxC.     

Community-based prevalence of rheumatic heart disease in rural Ethiopia: Five-year follow-up

BackgroundAs little is known about the prevalence and clinical progression of subclinical (latent) rheumatic heart disease (RHD) in sub-Saharan Africa, we report the results of a 5 year follow-up of a community based, echocardiographic study of the disease, originally carried out in a rural area around Jimma, Ethiopia.MethodsIndividuals with evidence of RHD detected during the baseline study as well as controls and their family members were screened with a short questionnaire together with transthoracic echocardiography.ResultsOf 56 individuals with RHD (37 definite and 19 borderline) in the original study, 36 (26 definite and 10 borderline) were successfully located 57.3 (range 44.9–70.7) months later. At follow-up two thirds of the definite cases still had definite disease; while a third had regressed. Approximately equal numbers of the borderline cases had progressed and regressed. Features of RHD had appeared in 5 of the 60 controls. There was an increased risk of RHD in the family relatives of borderline and definite cases (3.8 and 4.0 times respectively), notably among siblings. Compliance with penicillin prophylaxis was very poor.ConclusionsWe show the persistence of echocardiographically demonstrable RHD in a rural sub-Saharan population. Both progression and regression of the disease were found; however, the majority of the individuals who had definite features of RHD had evidence of continuing RHD lesions five years later. There was an increased risk of RHD in the family relatives of borderline and definite cases, notably among siblings. The findings highlight the problems faced in addressing the problem of RHD in the rural areas of sub-Saharan Africa. They add to the evidence that community-based interventions for RHD will be required, together with appropriate ways of identifying active disease, achieving adequate penicillin prophylaxis and developing vaccines for primary prevention.     

Experimental Infection of New Zealand White Rabbits (Oryctolagus cuniculi) with Leporid herpesvirus 4

Leporid herpesvirus 4 (LHV4) is a novel alphaherpesvirus recently identified in domestic rabbits (Oryctolagus cuniculi). Little is known about the pathogenesis or time course of disease induced by this virus. We therefore intranasally inoculated 22 female New Zealand white rabbits with 8.4 × 10⁴ CCID₅₀ of a clinical viral isolate. Rabbits were monitored for clinical signs, viral shedding in oculonasal secretions, and development and persistence of serum antibodies. Rabbits were euthanized at 3, 5, 7, 14, and 22 d postinfection (dpi) to evaluate gross and microscopic changes. Clinical signs were apparent between 3 to 8 dpi, and included oculonasal discharge, respiratory distress, and reduced appetite, and viral shedding occurred between 2 and 8 dpi. Seroconversion was seen at 11 dpi and persisted to the end of the study (day 22). Severe necrohemorrhagic bronchopneumonia and marked pulmonary edema were noted by 5 dpi and were most severe at 7 dpi. Pulmonary changes largely resolved by 22 dpi. In addition, multifocal splenic necrosis was present at 5 dpi and progressed to submassive necrosis by 7 dpi. Eosinophilic herpesviral intranuclear inclusion bodies were detected in the nasal mucosa, skin, spleen, and lung between 3 to 14 dpi. LHV4 is a pathogen that should be considered for rabbits that present with acute respiratory disease. LHV4 infection can be diagnosed based on characteristic microscopic changes in the lungs and spleen and by virus isolation. Serum antibody levels may be used to monitor viral prevalence in colonies.Abbreviations: CCID₅₀, 50% cell culture infectious dose; CRFK, Crandall feline kidney; dpi, days post infection; LHV4, Leporid herpesvirus 4; RHDV, rabbit hemorrhagic disease virus; S:P, sample:positiveHerpesviridae is a large family of enveloped, double-stranded DNA viruses within the order Herpesvirales. Viruses within this order are morphologically similar, possessing large genomes ranging from 125 to 290 kb. The linear DNA is packaged within an icosahedral capsid that is surrounded by a proteinaceous tegument and enclosed in a lipid envelope.¹⁰ The family Herpesviridae comprises more than 100 different virus species that infect mammals, birds, and reptiles. The family is divided into 3 subfamilies—alphaherpesviruses, betaherpesviruses, and gammaherpesviruses—according to distinguishing biologic properties of the viruses. Alphaherpesviruses demonstrate rapid lytic responses in cell culture, whereas betaherpesviruses are slow-growing, often producing giant cells in tissue, and gammaherpesviruses typically infect lymphoid tissue, leading to oncogenesis. Division into subfamilies on the basis of biologic behavior is also consistent with phylogenetic analysis.²⁹ Phylogenetic trees of the viral species are used to further subclassify viruses into genera, which typically closely follow the evolution of the host species.²³There are 4 known herpesviruses of rabbits. Leporid herpesvirus 1 (cottontail herpesvirus) and Leporid herpesvirus 3 (Herpesvirus sylvilagus) are gammaherpesviruses that have been isolated from wild cottontail rabbits (Sylvilagus floridanus). Both LHV1 and LHV3 were isolated incidentally from primary kidney cell cultures during searches for papillomaviruses⁸ and other viruses.¹³ The minor differences in immunoreactivity between LHV1 and LHV3 suggest that they are unique viruses, but complete genetic analyses are unavailable.⁶ LHV3 infection can induce lymphoproliferative disease and neoplasia in cottontail rabbits,¹² but the virus is unable to establish productive infection in domestic rabbits, such as New Zealand white rabbits (Oryctolagus cuniculi).¹⁴ No infection trials with LHV1 have been reported. Leporid herpesvirus 2, also known as virus 3 and Herpesvirus cuniculi, is a gammaherpesvirus that was first isolated in domestic laboratory rabbits during the search for the causative agent of chickenpox.³¹ LHV2 was later isolated as a slow-growing contaminant of a primary rabbit kidney cell culture.²⁵ Early infection studies with LHV2 demonstrated induction of neurologic signs, including nonsuppurative encephalitis with classic herpetic intranuclear inclusion bodies, after intracerebral inoculation.³¹ Recent studies suggest the histologic evidence of a mild, subclinical encephalitis after infection of New Zealand white rabbits.³⁷ Natural infections of Human herpesvirus 1 (herpes simplex 1) have been reported in rabbits, resulting in fatal encephalitis.^24,32,36Leporid herpesvirus 4 (LHV4) is a novel herpesvirus that was independently diagnosed and isolated from commercial rabbits in Alaska¹⁹ and a pet rabbit in northern Ontario.⁵ In 1990, cases of rabbit disease with similar clinical signs were reported among commercial meat rabbits in Alberta and British Columbia; the etiologic agent in these 2 cases was identified as a herpesvirus, but further genetic analyses were not performed.^27,33 Affected rabbits show variable clinical signs including lethargy, anorexia, conjunctivitis, fever, and abortion. Predominant pathologic findings include hemorrhagic dermatitis, splenic necrosis, hepatic necrosis, and multifocal pulmonary hemorrhage and edema. Distinctive glassy eosinophilic herpetic intranuclear inclusion bodies were observed in the skin and mesenchymal cells of the spleen and lung.^5,18 Postinfection morbidity and mortality have been reported to be 50% and 20%, respectively. However, the clinical disease and time course have not been studied previously, and only anecdotal reports from veterinary clients have been described. On the basis of its rapid growth and cytopathic effect in cell culture, LHV4 is classified as an alphaherpesvirus. Phylogenetic analysis of multiple genes has indicated that LHV4 segregates to the genus Simplexvirus,^2,18 which is unusual because this genus consists primarily of primate herpesviruses. The only other nonprimate species in this family are Bovine herpesvirus 2, Macropodid herpesvirus 1, and Macropodid herpesvirus 2,¹⁰ suggesting that these viral species may have migrated from primates, such as human caregivers, to these other species.²²With the emergence of a newly recognized infectious disease of rabbits, it is important to consider its effect on all domestic rabbit populations, including those used in research. In addition to welfare concerns, infectious disease can introduce unacceptable variability in research data.²¹ Guidelines for the care and use of laboratory animals from the Canadian Council on Animal Care and National Academy of Sciences indicate a need for the surveillance and eradication of known pathogens.^7,15 Furthermore, many studies use rabbits to answer research questions about other alphaherpesviruses. The rabbit is a popular model for the ocular keratitis induced by Herpes simplex virus 1 ⁹ and for the study of Bovid herpesvirus 1 and Bovid herpesvirus 5.³⁴ In addition, rabbits have been used in investigations of Macacine herpesvirus 1 (B virus) infections.⁴ As illustrated with the discovery of LHV2, rabbit cell cultures are often used to isolate viruses.^25,31 The presence of either active or latent LHV4 infection could seriously affect the interpretation of findings from these studies. It is imperative that laboratory animal veterinarians be aware of LHV4 and be able to identify and diagnose infections in rabbits.A preliminary investigation of a suspected herpesvirus infection in 2 domestic New Zealand white rabbits demonstrated splenic and hepatic necrosis, pulmonary congestion and edema, and necrosis at the site of inoculation.²⁷ After the initial discovery of LHV4, a few young New Zealand white rabbits were experimentally inoculated both intranasally and intracorneally with very large doses of virus and developed conjunctivitis and systemic illness.¹⁸ Pathology was conducted only on one animal at the peak of infection, and revealed splenic and lymph node necrosis.¹⁸ Whether rabbits can recover from the disease, how long they shed virus after infection, and if and when protective antibody titers develop were not evaluated.In the current study, we characterized the progression of clinical signs and the gross and microscopic changes after the intranasal inoculation of adult female New Zealand white rabbits with a sublethal dose of LHV4. We further evaluated viral shedding, neutralizing antibody production, and the recovery of rabbits from infection. Although bacterial infection may contribute to the progression and severity of disease in pet or commercial rabbit settings, we used SPF rabbits to isolate the direct pathologic effects of LHV4. This study provides essential information to veterinarians for the diagnosis of LHV4 in rabbits during various stages of active infection and convalescence.     

Disparity in the DNA translocase domains of SWI/SNF and ISW2

An ATP-dependent DNA translocase domain consisting of seven conserved motifs is a general feature of all ATP-dependent chromatin remodelers. While motifs on the ATPase domains of the yeast SWI/SNF and ISWI families of remodelers are highly conserved, the ATPase domains of these complexes appear not to be functionally interchangeable. We found one reason that may account for this is the ATPase domains interact differently with nucleosomes even though both associate with nucleosomal DNA 17–18 bp from the dyad axis. The cleft formed between the two lobes of the ISW2 ATPase domain is bound to nucleosomal DNA and Isw2 associates with the side of nucleosomal DNA away from the histone octamer. The ATPase domain of SWI/SNF binds to the same region of nucleosomal DNA, but is bound outside of the cleft region. The catalytic subunit of SWI/SNF also appears to intercalate between the DNA gyre and histone octamer. The altered interactions of SWI/SNF with DNA are specific to nucleosomes and do not occur with free DNA. These differences are likely mediated through interactions with the histone surface. The placement of SWI/SNF between the octamer and DNA could make it easier to disrupt histone–DNA interactions.     

Thermodynamic characterization of two homologous protein complexes: Associations of the semaphorin receptor plexin‐B1 RhoGTPase binding domain with Rnd1 and active Rac1

Plexin receptors function in response to semaphorin guidance cues in a variety of developmental processes involving cell motility. Interactions with Rho, as well as Ras family small GTPases are critical events in the cell signaling mechanism. We have recently determined the structure of a cytoplasmic domain (RBD) of plexin‐B1 and mapped its binding interface with several Rho‐GTPases, Rac1, Rnd1, and RhoD. All three GTPases associate with a similar region of this plexin domain, but show different functional behavior in cells. To understand whether thermodynamic properties of the GTPase–RBD interaction contribute to such different behavior, we have examined the interaction at different temperatures, buffer, and pH conditions. Although the binding affinity of both Rnd1 and Rac1 with the plexin‐B1 RBD is similar, the detailed thermodynamic properties of the interactions are considerably different. These data suggest that on Rac1 binding to the plexin‐B1 RBD, the proteins become more rigid in the complex. By contrast, Rnd1 binding is consistent with unchanged or slightly increased flexibility in one or both proteins. Both GTPases show an appreciable reduction in affinity for the dimeric plexin‐B1 RBD indicating that GTPase binding is not cooperative with dimer formation, but that a partial steric hindrance destabilizes the dimer. However, a reduced affinity binding mode to a disulphide stabilized model for the dimeric RBD is also possible. Consistent with cellular studies, the interaction thermodynamics imply that further levels of regulation involving additional binding partners and/or regions outside of the RhoGTPase binding domain are required for receptor activation.