Prevalence of antibodies to selected viruses in bovine embryo donors and recipients from Brazil,and its implications in international embryo trade

Summary The prevalence of serum antibody to enzootic bovine leukosis (EBL), bluetongue (BT), bovine herpesvirus 1 (BHV 1) and bovine virus diarrhoea (BVD) viruses in-bovine embryo donors (D) and recipients (R) from Minas Gerais State, Brazil was investigated. Of 451 sera (130 D plus 321 R) tested for antibodies against EBL virus 104 (23·1%) were positive. Of 410 sera (130 D plus 280 R) tested for antibody to BT, BHV 1 and BVD viruses the respective number of positive sera were 313 (76·3%), 209 (51·0%) and 153 (37·3%). Donors had significantly (Chi-square test,p<0.05) higher prevalence rates of antibody than recipients to EBL and BVD viruses. The donors were 60Bos indicus and 70Bos taurus purebred cows. Antibody to EBL virus was significantly less common amongBos indicus.

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Resumen Se investigó la prevalencia de anticuerpos séricos de leucosis bovina (LB), lengua azul (LA) virus herpes bovino 1 (VHB 1) y diarrea viral bovina (DVB), en donantes (D) y recipientes (R), en el estado de Minas Gerais, Brasil. De 451 sueros (130 D más 321 R) analizados para detectar anticuerpos contra leucosis, 104 (23·1%) fueron positivos. De 410 sueros (130 D más 280 R) analizados para detectar anticuerpos contra LA, DVB y VHB 1, los sueros positivos fueron 313 (76·3%), 153 (37·3%) y 209 (51·0%), respectivamente. Los donantes tuvieron tasas de prevalencia de anticuerpos contra LB y DVB mayores que los recipientes (chi-cuadradaP<0·05). Los donantes fueron 60Bos indicus y 70Bos taurus puros. Los anticuerpos contra el virus de la LB fueron menos comunes enB. indicus.

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Résumé Les auteurs ont recherché la prévalence des anticorps sériques au regard des virus de la leucose enzootique bovine (LEB), de la fièvre catarrhale du mouton (FCM), de l’herpès bovin (HB1) et de la diarrhée virale bovine (DVB) chez des bovins donneurs (D) et receveurs (R) d’embryons originaires de l’Etat de Minas Gerais au Brésil. Sur 451 sérums testés (130 D et 321 R) pour leurs anticorps vis-à-vis de la leucose enzootique bovine (LEB), 104 (23·1 p.100) étaient positifs. Sur 410 sérums testés (130D et 280 R) pour leurs anticorps contre la FCM, le virus de l’herpès bovin (VHB1) et celui de la diarrhée virale bovine (DVB), les souches de sérums respectivement positifs étaient de 313 (76·3 p. 100), 209 (51·08 p. 100) et 153 (37·3 p. 100). Les donneurs avaient des taux de prévalence d’anticorps significativement plus élevés que les receveurs (test de x² àP<0,05) vis-à-vis des virus de la leucose enzootique et de la diarrhée virale bovine. Les donneurs, tous de race pure, étaient au nombre de 60Bos indicus et de 70Bos taurus. L’anticorps de la leucose bovine enzootique était significativement moins courant chezBos indicus.

     

Viruses with bisegmented double-stranded RNA in pig faeces

Viruses similar to the bisegmented double-stranded (ds) RNA picobirnaviruses described in human faeces and the intestinal contents of Oryzomys nigripes rats and guinea pigs were isolated from the faeces of pigs taken from several areas in the state of Sao Paulo, Brazil. Samples were collected from 912 pigs of several breeds, aged nine to 61 days, and assayed by polyacrylamide gel electrophoresis with silver staining and a combined enzyme immunoassay for rotavirus and adenovirus, using the simian rotavirus SA11 as control. Electrophoretic profiles resembling the bisegmented dsRNA viruses were detected in 106 pigs with 15.3 per cent occurring in animals with diarrhoea compared to 9.6 per cent in animals without diarrhoea.     

Genetic parameter estimates for gastrointestinal nematode parasite resistance and maternal efficiency indicator traits in Santa Inês breed

Infection with Haemonchus contortus is the most economically important gastrointestinal nematode parasitosis and the most important cause of mortality in sheep production. The aim of this study was to estimate variance components of gastrointestinal parasite resistance traits, maternal efficiency (ME) and ewe adult weight (AW) in Santa Inês breed in tropical conditions. The phenotypic records were collected from 700 animals, belonging to four flocks located south‐east and north‐east in Brazil. The evaluated traits were as follows: degree of anaemia assessed using the FAMACHA chart (FMC), haematocrit (HCT), white blood cell (WBC), red blood cell (RBC), haemoglobin (HGB), platelets (PLT), faecal egg count (EPG_log), ME, metabolic maternal efficiency (MME), AW and metabolic ewe adult weight (MAW). From the 700 animals, 576 (82% of the evaluated population) were genotyped with the Ovine SNP12k BeadChip (Illumina, Inc.). Markers with unknown genomic position, located on sex chromosomes, monomorphic, with minor allele frequency <0.05, call rate <90% and with excess heterozygosity were excluded. The variance components were estimated using a single‐trait animal model with ssGBLUP procedure. The correlation between the parasite's resistance indicators and the ME suggested that selecting animals with both higher adult weight and ME will also favour the selection of animals with better resistance to gastrointestinal nematodes parasites, specially H. contortus. Therefore, since there are few or no studies with Santa Inês breed in this area, it is important to study those traits to better manage selection programs.     

Genomic regions and enrichment analyses associated with carcass composition indicator traits in Nellore cattle

The aim of this study was to estimate genetic parameters and identify genomic regions associated with carcass traits obtained by ultrasound and visual scores in Nellore cattle. Data from ~66,000 animals from the National Association of Breeders and Researchers (ANCP) were used. The variance components for backfat thickness, rump fat thickness and Longissimus muscle area (LMA) were estimated considering a linear model whereas a threshold model for body structure (BS), finishing precocity (FP) and musculature (MS) traits. The SNP solutions were estimated using the ssGBLUP approach by considering windows of 10 consecutive SNPs. Regions that accounted for more than 1.0% of the additive genetic variance were used. Genes identified within the significant windows, such as FOXA3, AP2S1, FKRP, NPASI and ATP6V1G1, were found to be related with MS, while OMA1 and FFGY with BS and FP traits. The PLTP, TNNC2 and GPAT2 genes were found in the regions associated with LMA, as well as TKT, FNDC5 and CHRND can strongly be related with fat deposition. Gene enrichment analysis revealed processes that might be directly influenced the organism growth and development. These results should help to better understand the genetic and physiological mechanisms regulating growth and body composition, muscle tissue development and subcutaneous fat expression, and this information might be useful for future genomic studies in Nellore cattle.     

The coppice-with-standards silvicultural system as applied to Eucalyptus plantations — a review

We review the management of Eucalyptus species under a coppice-with-standards （CWS） silvicultural system. CWS management results in product diversification, permitting production of small and large scale timber from the same stand. Eucalyptus species are suitable candidates for CWS management because： there are large worldwide plantation areas, sprouting capacity is high, and eucalypts are multipur- pose species. We discuss （1） short rotation Eucalyptus coppice manage- ment for energy and pulping and （2） Eucalyptus seedling management for solid wood products. We review the literature and discuss experi- ences with Eucalyptus managed under the CWS system. We also assess projects dealing with Eucalyptus coppice management, stand density regulation, pruning, and stand and wood quality. The growth environ- ment of the standard trees （heavy competition up to the first harvest, free growth afterwards） coupled with long rotations （〉20 years） results in high quality logs for solid wood products. Early pruning should be ap- plied to enhance wood quality. We propose a system for the silvicultural management of Eucalyptus under the CWS system, elaborating on the consequences of initial planting density, site productivity, and standard tree densities as well as timing of basic silvicultural applications.     

Factors affecting secondary sex characteristics in the yellowtail tetra,Astyanax altiparanae

Fish Physiology and Biochemistry - This study interrogated factors which affect the appearance of secondary sexual characteristics, namely, fin spinelets (rigid dimorphic structure empirically...     

Quercetin induces structural chromosomal aberrations and uncommon rearrangements in bovine cells transformed by the E7 protein of bovine papillomavirus type 4

Bovine papillomavirus type 4 (BPV‐4) and bracken fern are cofactors in the carcinogenesis of the upper gastrointestinal (GI) tract of cattle. An experimental in vitro model system has been developed to analyse the co‐operation between the viral transforming protein E7, the cellular ras oncogene and quercetin, one of the mutagens of bracken fern, during neoplastic progression of primary bovine cells. We now report cytogenetic studies of these cells at different stages of malignant transformation: parental primary non‐transformed PalF cells; E7R cells transformed by BPV‐4 E7 and activated ras but not tumorigenic, and tumorigenic E7Q cells derived from E7R cells after treatment with quercetin. All cell lines presented increased numbers of aneuploid cells. The rate of structural chromosomal aberrations observed was increased in transformed cells. In addition, E7Q cells showed chromosomes with peculiar rearrangements, which resulted in metacentric and submetacentric marker chromosomes, with an increase in the mean chromosome arm number. These markers were the products of possible centric fusions. These aberrations and rearrangements were distributed throughout the karyotype, no specific chromosome was involved and the heterochromatic centromeric regions appeared to be preserved.     

Genetic control of Asian rust in soybean

The objective of this study was to investigate the genetic mechanisms of soybean resistance to Asian rust (Phakopsora pachyrhizi Syd. & P. Syd). F2 and F3 generations from 15 diallel crosses involving six soybean cultivars, FT-2, EMBRAPA 48, BRS 154, BRS 184, BRS 214, BRS 231, were used to analyze the genetic control of Asian rust resistance in the soybean parents tested. Genetic models were fitted to means and variances of the generations tested in a completely randomized field experiment with 5,700 hill plots. The experiment was spray-inoculated twice with an isolate that was first detected during the 2002/03 season in Mato Grosso (MT) State and presently prevail in Central Brazil, at a six-day interval, on borders rows and on the useful area, respectively, with a 10⁴ spores/ml distilled H₂O suspension. Assessments were made using a diagrammatic scale for disease severity at seven and 39 days after the first detection of Asian rust in the experiments. Evaluations made in the second assessment (39 days) discriminated better between genotypes. Selection at early plant developmental stages may not result in adult resistant plants. Cultivar FT-2, which had presented monogenic resistance to a rust isolated that prevailed in the first two years of rust occurrence in Brazil, showed no resistance to the MT State rust strain used in this experiment, but eleven crosses showed genetic variability for resistance in the second assessment. Soybean rust resistant genes showing predominantly additive effects are dispersed among parents. Narrow sense heritability values ranging from 0.42 to 0.74 at the F3 family level in the second assessment suggested that selection of resistant genotypes is feasible.     

Change in Physical Properties of Ferralsols with Tree Planting in the Central Amazon, Brazil

We examined the effects of mixed planting of fast growing tree species with indigenous Amazon tree species and soil tillage practices on soil physical properties in a deforested site used for agricultural cultivation. The site was located in the Central Amazon and consisted of Ferralsols. Bulk density and soil hardness were compared in the mixed planting site and an area where only indigenous tree species were planted. Many roots of the fast growing trees penetrated into the profile and caused changes in soil physical properties, i.e., decreasing bulk density and hardness. When tillage practices prior to planting were combined with mixed planting, the changes in soil physical properties were enhanced and the growth of not only the planted fast growing trees but also indigenous species such as mahogany, Swietenia macrophylla , which is shade tolerant, was accelerated.     

Lithospheric Contributions to Arc Magmatism: Isotope Variations Along Strike in Volcanoes of Honshu, Japan

Major chemical exchange between the crust and mantle occurs in subduction zone environments, profoundly affecting the chemical evolution of Earth. The relative contributions of the subducting slab, mantle wedge, and arc lithosphere to the generation of island arc magmas, and ultimately new continental crust, are controversial. Isotopic data for lavas from a transect of volcanoes in a single arc segment of northern Honshu, Japan, have distinct variations coincident with changes in crustal lithology. These data imply that the relatively thin crustal lithosphere is an active geochemical filter for all traversing magmas and is responsible for significant modification of primary mantle melts.