FV blood group and haemoglobin type versus haematological and blood chemical parameters in young Swiss bulls

A relationship between the FV blood group phenotype and 4 out of 45 haematological and blood chemical parameters--red cell number, mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), and serum iron--has been demonstrated in young bulls of three Swiss cattle breeds. There was also a relationship between haemoglobin type and 7 out of 45 haematological and blood chemical parameters (haemoglobin concentration, red cell number, MCV, MCHC and red cell concentrations of K+ and Na+ and their sum). In addition to expanding the species in which there is an effect of haemoglobin phenotype on MCV to include cattle, these data also demonstrate a significant correlation between their FV phenotype and MCV.     

The molecular phylogenetics of the genus Oligoryzomys (Rodentia: Cricetidae) clarifies rodent host–hantavirus associations

Several species of the genus Oligoryzomys are natural hosts of different hantavirus genotypes affecting humans. The systematics of the genus is confusing, which complicates the identification of the rodent host and hence the potential endemic areas of hantavirus pulmonary syndrome. In this study, we analyse molecular data to infer phylogenetic relationships among Central and South American specimens of Oligoryzomys, and compare our results with previously published data on karyotypic, geographic distribution and host–virus associations to solve contradictory taxonomic reports. We identified 25 clades, each one corresponding to a different putative species. The phylogenetic trees show that Oligoryzomys longicaudatus is strongly related to the Oligoryzomys flavescens complex, which comprises four clades; Oligoryzomys nigripes is related to Oligoryzomys stramineus, Oligoryzomys vegetus is related to Oligoryzomys fulvescens from Central America, and Oligoryzomys brendae is the sister species of Oligoryzomys aff. destructor. We identified the following rodent host–hantavirus genotype relationships: O. longicaudatus–Andes; O. flavescens ‘West'–Bermejo; O. flavescens ‘East'–Lechiguanas; O. nigripes–Juquitiba; Oligoryzomys microtis–Rio Mamore and Rio Mamore‐3; Oligoryzomys chacoensis–Oran; Oligoryzomys costaricencis–Choclo; Oligoryzomys delicatus–Maporal; Oligoryzomys utiaritensis–Castelo dos Sonhos; Oligoryzomys sp. RT2012–Rio Mamore‐4; Oligoryzomys sp. (and not Oligoryzomys fornesi)–Anajatuba. This work, besides contributing to the development of prevention programmes for hantavirus epidemiology in Latin America, represents a comprehensive update of the systematics of the genus Oligoryzomys. © 2014 The Linnean Society of London     

Phylogenetic relationships among species of the genus Oligoryzomys (Rodentia,Cricetidae) from Central and South America

González‐Ittig, R. E., Salazar‐Bravo, J., Barquez, R. M. & Gardenal, C. N. (2010). Phylogenetic relationships among species of the genus Oligoryzomys (Rodentia, Cricetidae) from Central and South America. —Zoologica Scripta, 39, 511–526. The genus Oligoryzomys includes several species very similar in external morphology, which has resulted in a confusing specific taxonomy. Accurate species identification is particularly important because several species of Oligoryzomys act as natural hosts of hantaviruses affecting humans. Here, we assign specific status to individuals from a wide geographical area of Argentina and Chile using sequences of the mtDNA control region. We also compare cytochrome b sequences of 14 species recognized from Central and South America to infer the phylogenetic relationships within the genus. In addition, the results were analysed using available data on chromosome numbers, and the host–parasite relationships reported for the genus Hantavirus. We confirm the geographical distribution of Oligoryzomys longicaudatus (Argentina, Chile), Oligoryzomys nigripes (Argentina, Paraguay, Brazil), Oligoryzomys chacoensis (Argentina, Bolivia, Paraguay), Oligoryzomys fornesi (Argentina, Paraguay), Oligoryzomys destructor (Argentina, Bolivia) and Oligoryzomys microtis (Bolivia, Brazil). Oligoryzomys longicaudatus is strongly related to the Oligoryzomys flavescens complex, which comprises four clades; O. nigripes is closely related to Oligoryzomys stramineus, and Oligoryzomys vegetus, to Oligoryzomys fulvescens from Central America. Oligoryzomys chacoensis, O. destructor, O. fornesi, O. longicaudatus, O. microtis, O. nigripes, O. stramineus, Oligoryzomys moojeni, Oligoryzomys rupestris, O. fulvescens and O. vegetus are confirmed as valid species, whereas O. flavescens, Oligoryzomys magellanicus, Oligoryzomys griseolus, Oligoryzomys victus, Oligoryzomys andinus and Oligoryzomys arenalis need exhaustive revision. The sister species to all the remaining entities of the genus was O. microtis, suggesting an Amazonian origin for the genus.     

Recent range expansion and low levels of contemporary gene flow in Calomys musculinus: its relationship with the emergence and spread of Argentine haemorrhagic fever

The geographic distribution of haplotype diversity in the rodent Calomys musculinus, sampled from 16 wild populations of Argentina, was analysed on two geographical scales. The species is the natural reservoir of the Junin virus, the etiological agent of the Argentine haemorrhagic fever (AHF). In all, 24 composite haplotypes were recognised in the mtDNA D-loop region. Haplotypes 1 and 2, internal in the network, were the most frequent and were present in almost all populations. The absence of large genetic gaps between widely distributed haplotypes, the existence of exclusive haplotypes in more than 50% of the sampled populations and the absence of isolation by distance at a macrogeographical scale are in support of the hypothesis of a recent range expansion of the populations of the Humid Pampa, with low to moderate current gene flow. The dispersal of this opportunistic species would have been favoured by the explosive increments in density after agriculture was introduced. When only nearby populations within the endemic area of AHF were considered, a pattern of isolation by distance was detected. At present, genetic drift appears to be the main force acting to randomly differentiate C. musculinus populations, which would also lead to random differentiation of Junin virus strains and a reduction in the virulence of the pathogen in 'historic' AHF areas. The knowledge of migration patterns of the reservoir populations facilitates reliable prediction of the potential spread of the human disease.     

Haplotype diversity of the mitochondrial DNA D-loop region in Calomys musculinus (Rodentia,Muridae) detected by PCR-RFLP

In order to contribute to knowledge of colonization patterns in the rodent Calomys musculinus, a natural reservoir of the virus producing Argentine hemorrhagic fever (AHF), we studied the haplotype diversity of the mitochondrial DNA D-loop region in five natural populations from central Argentina. Digestion with eight restriction enzymes (RsaI, MseI, Tsp509I, AluI, AciI, HaeIII, NlaIII, and AseI) revealed polymorphism in the 1300 bp fragment amplified by PCR. Twenty different composite haplotypes were detected. Hierarchical analyses indicated that almost all variation (94%) is contained within local populations. Haplotypes 1 and 2, shared by all populations, were the most frequent. Nonsignificant genetic differentiation was found among populations of the endemic and nonendemic areas of AHF: All locations sampled presented exclusive haplotypes in spite of their geographic proximity, which would support previous observations indicating restricted gene flow among C. musculinus populations.     

Composition and enzyme activities of Spiroplasma citri membranes.

Spiroplasma citri was cultured in three different media that supplied cholesterol and fatty acids from: (i) horse serum, (ii) pleuropneumonia-like organism (PPLO) serum fraction, or (iii) bovine serum albumin-fatty acid-cholesterol. The ability of PPLO serum fraction to support growth varied by lot number. Neither PPLO serum fraction nor the bovine serum albumin medium supported growth as well as the horse serum medium. Analysis of cholesterol, lipid phosphorus, and membrane protein showed the horse serum- and PPLO-grown cells to be indistinguishable, but the bovine serum albumin-grown cells were deficient in lipid phosphorus. The three cultures did not show markedly different fatty acid compositions, but, in all cases, the cultures preferentially incorporated palmitic acid and discriminated against linoleic acid. Cultures grown for different times from logarithmic growth through a degenerative phase showed relatively constant ratios of cholesterol/protein and lipid phosphorus/protein. Fatty acid composition was also relatively constant at the different stages. Adenosine triphosphatase and p-nitrophenyl phosphatase were mainly associated with the membrane, whereas reduced nicotinamide adenine dinucleotide oxidase was either readily removed or not associated with the membrane. The reduced nicotinamide adenine dinucleotide oxidase was inactivated at temperatures above 35 degrees C.     

Nuclear antisense effects in cyclophilin A pre-mRNA splicing by oligonucleotides: a comparison of tricyclo-DNA with LNA

The nuclear antisense properties of a series of tricyclo (tc)-DNA oligonucleotide 9–15mers, targeted against the 3′ and 5′ splice sites of exon 4 of cyclophilin A (CyPA) pre-mRNA, were evaluated in HeLa cells and compared with those of corresponding LNA-oligonucleotides. While the 9mers showed no significant antisense effect, the 11–15mers induced exon 4 skipping and exon 3+4 double skipping to about an equal extent upon lipofectamine mediated transfection in a sequence- and dose-dependent manner, as revealed by a RT–PCR assay. The antisense efficacy of the tc-oligonucleotides was found to be superior to that of the LNA-oligonucleotides in all cases by a factor of at least 4–5. A tc-oligonucleotide 15mer completely abolished CyPA mRNA production at 0.2 µM concentration. The antisense effect was confirmed by western blot analysis which revealed a reduction in CyPA protein to 13% of its normal level. Fluorescence microscopic investigations with a fluorescein labeled tc-15mer revealed a strong propensity for homogeneous nuclear localization of this backbone type after lipofectamine mediated transfection, while the corresponding lna 15mer showed a less clear cellular distribution pattern. Transfection without lipid carrier showed no significant internalization of both tc- and LNA- oligonucleotides. The obtained results confirm the power of tc-DNA for nuclear antisense applications. Moreover, CyPA may become an interesting therapeutic target due to its important role in the early steps of the viral replication of HIV-1.     

Position-dependent effects on stability in tricyclo-DNA modified oligonucleotide duplexes

A series of oligodeoxyribonucleotides and oligoribonucleotides containing single and multiple tricyclo(tc)-nucleosides in various arrangements were prepared and the thermal and thermodynamic transition profiles of duplexes with complementary DNA and RNA evaluated. Tc-residues aligned in a non-continuous fashion in an RNA strand significantly decrease affinity to complementary RNA and DNA, mostly as a consequence of a loss of pairing enthalpy ΔH. Arranging the tc-residues in a continuous fashion rescues T_m and leads to higher DNA and RNA affinity. Substitution of oligodeoxyribonucleotides in the same way causes much less differences in T_m when paired to complementary DNA and leads to substantial increases in T_m when paired to complementary RNA. CD-spectroscopic investigations in combination with molecular dynamics simulations of duplexes with single modifications show that tc-residues in the RNA backbone distinctly influence the conformation of the neighboring nucleotides forcing them into higher energy conformations, while tc-residues in the DNA backbone seem to have negligible influence on the nearest neighbor conformations. These results rationalize the observed affinity differences and are of relevance for the design of tc-DNA containing oligonucleotides for applications in antisense or RNAi therapy.