Molecular characterization of a stable antisense chalcone synthase phenotype in strawberry (Fragaria x ananassa)

An octaploid (Fragaria x ananassa cv. Calypso) genotype of strawberry was transformed with an antisense chalcone synthase (CHS) gene construct using a ripening related CHS cDNA from Fragaria x ananassa cv. Elsanta under the control of the constitutive CaMV 35S promoter via Agrobacterium tumefaciens. Out of 25 transgenic lines, nine lines showed a reduction in CHS mRNA accumulation of more than 50% as compared to the untransformed cv. Calypso control. The antisense CHS construct was found to be integrated into the genome, with a copy number ranging from one to four. The pigmentation of the fruit was only affected when less than 5% of the control CHS expression level was detected. A stable antisense phenotype over a period of 4 years was obtained in the primary transgenic lines at a rate of 1:20. As a consequence of the reduced activity of CHS, the levels of anthocyanins, flavonols, and proanthocyanidins were downregulated and precursors of the flavonoid pathway were shunted to the phenylpropanoid pathway leading to highly increased levels of cinnamoyl glucose (520% of control), caffeoyl glucose (816% of control), and feruloyl glucose (1092% of control) as well as p-coumaryl alcohol (363% of control) and p-coumaryl-1-acetate (1079% of control), which occur only as trace components in untransformed control fruits. These results demonstrate that the introduction of an antisense CHS construct in strawberry results in an unpredictable biochemical phenotype, thereby confirming that CHS function is an important regulatory point of substrate flow between the flavonoid and the phenylpropanoid pathways.     

Massive-star supernovae as major dust factories

We present late-time optical and mid-infrared observations of the Type II supernova 2003gd in the galaxy NGC 628. Mid-infrared excesses consistent with cooling dust in the ejecta are observed 499 to 678 days after outburst and are accompanied by increasing optical extinction and growing asymmetries in the emission-line profiles. Radiative-transfer models show that up to 0.02 solar masses of dust has formed within the ejecta, beginning as early as 250 days after outburst. These observations show that dust formation in supernova ejecta can be efficient and that massive-star supernovae could have been major dust producers throughout the history of the universe.     

A structural equation model for describing relationships between somatic cell score and milk yield in dairy goats

The relationship between milk yield and somatic cell score (log-transformed somatic cell count) in dairy goats may involve complex pathways with recursive or simultaneous effects. Structural equation models were fitted to longitudinal data on milk yield and on somatic cell scores. Data consisted of 4 repeated records of milk production and of somatic cell score from left and right halves of the udder in each of 47 dairy goats; infection status of each of the halves at each test day was also available. Results strongly suggest the existence of a within-half, first-order autoregressive process and of simultaneity of effects between somatic cell scores from the left and right halves of the udder. This indicates that the immune response to an infection is not restricted to the half of the udder in which the infection takes place and that it tends to propagate over time. The existence of a negative effect of somatic cell score on milk yield was also supported by the results; however, evidence in favor of an effect in the opposite direction, a dilution effect, was not strong.     

Efficiency of utilizing ileal digestible lysine and threonine for whole body protein deposition in growing pigs is reduced when dietary casein is replaced by wheat shorts

To determine the effect of dietary inclusion level of wheat shorts (WS; a high nonstarch poly-saccharide-containing feed ingredient) and casein (CS; a control) on the efficiency of utilizing ileal digestible Lys (kLys) and Thr (kThr) for whole body protein deposition (PD) in the growing pig, 2 separate N-balance studies were conducted with either Lys or Thr as first-limiting AA in cornstarch-based diets. For the Lys study, a basal diet (L-basal) was formulated to contain 0.24 g of standardized ileal digestible (SID) Lys per MJ of DE, to which 0.095 or 0.19 g of SID Lys per MJ of DE were added using either CS (L-CS2 or L-CS3, respectively) or WS (L-WS2 or L-WS3, respectively). A sixth diet was evaluated that was similar to L-CS3 but to which 6% pectin (L-pectin) was added as a source of soluble nonstarch polysaccharides. For the Thr study, the basal diet (T-basal) was formulated to contain 0.14 g of SID Thr per MJ of DE, to which 0.055 or 0.11 g of SID Thr per MJ of DE were added from CS (T-CS2 or T-CS3, respectively) or from WS (T-WS2 and T-WS3, respectively). A sixth diet was evaluated that was similar to T-CS3 but to which 6% pectin was added (T-pectin). Increasing SID Lys intake from CS did not influence kLys for PD (P > 0.10), whereas increasing SID Lys intake from WS reduced kLys for PD (P = 0.001; 89 vs. 79%). Inclusion of 6% pectin had no effect on kLys for PD (P > 0.10). Increasing SID Thr intake from CS also did not influence kThr for PD (P > 0.10), whereas kThr for PD was reduced at the greatest dietary inclusion level of WS (P < 0.001; 90 vs. 77%). Pectin inclusion had no effect on kThr for PD (P > 0.10). The inefficiency of utilizing ileal digestible Lys intake for PD may be attributed to nonreactive Lys in WS. The negative impact of including high levels of WS in the diet of pigs on kThr seems to be associated with fiber content of WS; it was not related to increased endogenous ileal AA losses at the distal ileum. The impact of dietary AA source on the use of ileal digestible Lys and Thr for PD, or other body functions, is substantial and should be considered in the formulation of pig diets. Further research is warranted to elucidate the mechanisms contributing to substantial dietary effects on Thr use for PD.     

Prevalence of fetal resorption in stray dogs in Yucatan, Mexico

OBJECTIVES: To determine the prevalence of fetal resorption in 77 pregnant bitches and its association with the age, size and body condition score of the bitch and to determine the frequency of transuterine migration of embryos. METHODS: The number and position of embryos or fetuses and placental zones were registered postmortem. The prevalence of fetal losses was determined by comparing the number of corpora lutea with the number of embryos or fetuses in each bitch. The prevalence of transuterine migration of embryos was determined by correlating the number of fetuses in each horn and the number of corpora lutea in the ipsilateral ovary. RESULTS: Fetal resorption zones were demonstrated in 42.9 per cent of the bitches. However, pregnancy continued in 84.9 per cent of cases. Of the fetal losses, 25.9 per cent were determined by counting the number of corpora lutea and viable embryos or fetuses. Young bitches tended to have a higher probability of fetal resorption than adult bitches (P<0.06). The presence of fetal resorption zones was not associated with size or body condition. Transuterine migration of embryos had occurred in 15.8 per cent of the bitches. CLINICAL SIGNIFICANCE: This study demonstrated that embryo resorption is a normal event in the bitches, with a higher prevalence than previously thought.     

Horizontal Maedi-Visna virus (MVV) infection in adult dairy-sheep raised under varying MVV-infection pressures investigated by ELISA and PCR

A three year long experimental study was carried out to investigate horizontal MVV-infection by PCR and ELISA, in 191 one year-old latxa dairy-sheep raised in two separate groups under low and high MVV-infection pressure, respectively. Sheep originated from a previous MVV-transmission study in lambs and seroprevalence among one year-old sheep in both groups was 15% approximately. The high infection-pressure group (H-group) consisted of 147 replacement ewes that joined a milk-producing, housed dairy-flock with 42-66% MVV-seroprevalence and the low infection-pressure group (L-group) were castrated males raised in a separate shed. In contrast to results obtained when infection was investigated in lambs, the overall degree of agreement between ELISA and PCR results was very good and there was some indication that it increased further as sheep became older. MVV-prevalence did not change in the L-group and increased to 57% in three year-old sheep in the H-group (p<0.001). Random effects logistic regression confirmed seroconversion was significantly higher in the H-group compared to the L-group and was highest during the year after the sheep were introduced in the dairy flock and did not increase with age as in previous studies using less sensitive antibody assays. The evidence that horizontal transmission can be very low in spite of prolonged close contact between infected and non-infected sheep is valuable for MVV-control purposes. Furthermore it highlights the need to investigate virus excretion dynamics in infected animals and animal to animal transmission to improve our overall understanding of horizontal MVV transmission in MVV endemic populations.     

Bluetongue in The Netherlands; description of the first clinical cases and differential diagnosis. Common symptoms just a little different and in too many herds

For the first time Bluetongue (BT) has been diagnosed in the Netherlands. The clinical symptoms of BT on five farms during the first outbreak ever in the Netherlands are described. Fever and swollen sensitive coronets leading to reluctance to stand and walk were sometimes the first symptoms. Later lesions in the mouth occurred with foamy salivation and respiratory problems. In other cases a swollen head with swollen lips and foamy salivation were the first clinical signs. Also sudden death occurred. In the first sixteen confirmed cases morbidity and mortality were lower than described in outbreaks in other countries. Good collaboration between practitioners, specialists of the Animal Health Service (GD-Deventer), and specialists of the Food and Consumer Product Safety Authority (VWA) and CIDC-Lelystad (Wageningen UR) led to a rapid notification and ultimately confirmation of the suspected diagnosis BT.