Plasticity of animal genome architecture unmasked by rapid evolution of a pelagic tunicate

Genomes of animals as different as sponges and humans show conservation of global architecture. Here we show that multiple genomic features including transposon diversity, developmental gene repertoire, physical gene order, and intron-exon organization are shattered in the tunicate Oikopleura, belonging to the sister group of vertebrates and retaining chordate morphology. Ancestral architecture of animal genomes can be deeply modified and may therefore be largely nonadaptive. This rapidly evolving animal lineage thus offers unique perspectives on the level of genome plasticity. It also illuminates issues as fundamental as the mechanisms of intron gain.     

Identification of toxigenic Pasteurella multocida in atrophic rhinitis of pigs by in vitro characterisation

Toxigenic strains of Pasteurella multocida were readily differentiated from non-toxigenic strains by an agarose overlay method using bovine turbinate cells or bovine lung cells. Cells which were young and densely confluent were best suited to this assay. The incubation period required to distinguish toxigenic strains was dependent on the confluence of the monolayers, which was affected by the seeding rate, cell passage level and growth time prior to overlay. The agarose overlay method correctly identified 11 of 11 reference strains of Pasteurella multocida, and visible cytotoxic changes were present in the monolayers after 48 to 65 h. Outbreaks of the enzootic form of atrophic rhinitis in 2 New South Wales piggeries were associated with the isolation of toxigenic type D strains of P. multocida.     

Uterine infection with bovine herpesvirus type 4 in dairy cows

Diseases of the reproductive tract are a frequent problem in dairy herds. Herpesviruses are uterine pathogens also involved in other clinical diseases; for example, bovine herpesvirus type 4 BoHV‐4 induces abortion, enteritis, metritis, pneumonia and vaginitis, but it can also be detected in healthy cows. The role of BoHV‐4 in the development of clinical endometritis (CE) or subclinical endometritis (SE) has not clearly been described. Therefore, the objective of this study was to describe the prevalence of uterine BoHV‐4 infection and its relationship with clinical, bacteriological and cytological findings in dairy cows 20–30 days after calving. The experiment was performed as a completely randomized block design, with farm (n = 10) as blocking criterion and with cow (n = 397) as the experimental unit. Logistic regression models were used to assess the effect of BoHV‐4 infection on CE, SE and reproductive performance. Proportion of cows infected with BoHV‐4 was 5.8% (n = 23/397). BoHV‐4 was isolated in 11.0% (n = 12/109), 4.8% (n = 4/84) and 3.6% (n = 7/194) of cows diagnosed as CE, SE or healthy, respectively. A logistic model revealed that BoHV‐4 infection showed a tendency to increase the risk for CE (AOR = 2.17; p = .10) but significantly reduced both, the odds for artificial insemination within 80 days post‐partum (dpp) (AOR = 0.37; p = .035) and for pregnancy within 200 dpp (AOR = 0.13; p = .004). Furthermore, BoHV‐4 infection increased the chance for intrauterine infection with Trueperella pyogenes (AOR = 5.55; p < .001) and vice versa (AOR = 5.79, p < .001). In conclusion, BoHV‐4 infection is associated with reduced chances for insemination and pregnancy by 200 dpp and showed a trend to be associated with increased risk for CE. Furthermore, BoHV‐4 and Trueperella pyogenes infections are strongly related.     

Lythrum hyssopifolia (lesser loosestrife) poisoning of sheep in Victoria

Objective To document an ovine disease attributed to the consumption of Lythrum hyssopifolia (lesser loosestrife). Procedures Historical and histological review of field and experimental cases. Results 1–20% mortality occurred in sheep flocks grazing paddocks where L. hyssopifolia was the predominant green vegetation. Well‐documented disease outbreaks occurred in summer on nine farms across Victoria between 1974 and 2002. Liver damage occurred in all nine outbreaks, with kidney damage in at least eight. Hepatocyte necrosis was usually zonal to midzonal (zone 2) in the liver samples from four farms and periacinar (zone 3) in those from three farms, but some livers showed only single‐cell necrosis. Multinucleate hepatocytes near necrotic areas were a feature in six cases. Proximal tubular epithelium appeared to be the primary renal target and brown granules were often present in renal tubules. Biochemical and histological evidence of liver and kidney damage was obtained from two sheep experimentally pen‐fed harvested L. hyssopifolia. Conclusion Chemicals in L. hyssopifolia are toxic to ovine hepatocytes and renal tubular epithelial cells.     

Vaccine efficacy for reducing turbinate atrophy and improving growth rate in piggeries with endemic atrophic rhinitis

Two vaccines, based on formalin-killed whole cells of toxigenic Pasteurella multocida type D and Bordetella bronchiseptica combined with a partially toxoided cell extract of P multocida, were prepared with Freund's incomplete adjuvant (vaccine 1) or by alum precipitation (vaccine 2). Each was tested for safety and efficacy in reducing the severity of nasal turbinate atrophy and improving the growth rate of pigs in three Western Australian commercial piggeries with endemic atrophic rhinitis. In safety experiments with vaccine 1, no adverse clinical effects were observed in vaccinated sows or their progeny. Piglets receiving vaccine 2 showed no injection site abnormalities, pyrexia or turbinate atrophy. In field trials, vaccine 1 significantly reduced the prevalence of moderate to severe nasal turbinate atrophy (Done score 3 to 5) when used in two piggeries (A and B). Progeny from vaccinated sows in piggery B also grew significantly faster than controls. When vaccine 2 was used in piggery A at a later date and in another piggery (C), growth rate was not improved in either piggery and the prevalence of moderate to severe turbinate atrophy was reduced only in piggery C.     

An approach to acorn production in Iberian dehesas

Acorn production is one of the most important products in silvopastoral systems in the Mediterranean region. In the present study we carried out two preliminary trials to analyze the distribution of production over time and the effect of pruning. The objective was to develop tools to manage this valuable resource within these systems. In the first part of the study, we analyzed the total acorn production of a holm oak stand, and its seasonal distribution (October–January) over two years (1997–1998 and 1998–1999) in five sites in the southwest of Spain. Mean total acorn production ranged from 590 to 830 kg ha⁻¹. There was considerable variation between the different sites and years studied, as was expected from studies on other oak species. A comparison was also made of acorn production, comparing annual acorn production between 40 pruned and 40 non-pruned trees, for the period 1994–1999. There was an interaction between ‘pruning treatment’ and ‘year’. Pruning, significantly decreased acorn production in all but two years when production was above the average, whereas production was not affected by pruning the three years that acorn yield was below the average. The study of acorn production and the analysis of the effect of pruning, needs to be studied over a longer time period.     

Assessment of Selected Quality Parameters of Epididymal Cat (Felis catus s. domestica,L. 1758) Sperm Using Flow Cytometry Method and Computer Assisted Sperm Analyser

The improvement of biotechnical methods connected with fast and precise semen quality assessment and its utilization in assisted reproductive techniques is an urgent necessity in felids. The aim of this study was to evaluate some quality parameters (i.e. the viability and share of cells with intact plasma membrane) of epididymal sperm of cats using the flow cytometry method and computer‐assisted sperm analysis (CASA) examination. The material consisted of epididymal spermatozoa flushed from 22 pairs of epididymes after routine neutering procedures obtained from domestic cats aged between 8 and 36 months. The epididymes were cut and incubated with an extender without egg yolk. The samples were assessed for sperm viability (Live/Dead Sperm Viability Kit^®), percentage of subtle membrane changes (Apoptosis Detection Kit^®) and motility using FACScalibur flow cytometer and assisted sperm analyser htm ivos version 12.2. The flow cytometry method revealed 71.3% and 84.4% of live sperm using Live/Dead Sperm Viability Kit and Apoptosis Detection Kit respectively. The population of early‐apoptotic and late‐apoptotic sperm were 0.8% and 1.1% respectively. The CASA examination found 51.5% of motile sperm. However, the motility examination under light microscope revealed 69.5% of motile sperm. The data revealed an indistinctive per cent of apoptotic cells and 18.9% and 15.6% of dead cells using Live/Dead Sperm Viability Kit and Apoptosis Detection Kit, respectively, which indicate that the sperm obtained after flushing the epididymis possess potential properties for further assisted reproduction techniques.