The diastereomeric ratio in the triadimenol produced by fungal metabolism of triadimefon,and its role in fungicidal selectivity

The ratio of the two diastereomeric forms of triadimenol, produced by the reduction of triadimefon in various fungi, was studied. The reduction of triadimefon in fungi seems to be a concentration-dependent process, the virtual irreversibility of which is proved. Not only the degree of triadimefon reduction, but also the ratio of the triadimenol diastereomers produced, was characteristic for each of the fungal species. A direct correlation, between the production of the more active diastereomeric form and the sensitivity of the fungal species to triadimefon, was observed.     

Relationship between ovarian weight and follicular population in heifers

The size of the ovary varies substantially among cattle. This variation may influence the potential of the ovary to produce follicles. In the present study, we examined whether a relationship exists between the weight of the ovary and the number of antral follicles >or=1 mm. Paired ovaries were obtained from Holstein x Japanese Black F1 heifers. Follicles were classified into three size categories (small: 1.0-<5.0 mm, medium: 5.0-<8.5 mm and large: >or=8.5 mm), and the number of follicles in each category was recorded. Large variations in the weight of ovaries and the number of follicles were observed among animals. Significant positive correlations (r>or=0.4, P<0.001) were found between the weight of intact ovaries and the number of follicles in all three categories for the ovary contralateral to CL (OCC) and in the small follicles for the ovary ipsilateral to CL (OIC). Significant positive correlations (r>0.4, P<0.0001) were also observed between the weight of ovaries devoid of CL and follicles and the number of small and medium follicles in both OIC and OCC, indicating that the correlation is not due to the increase in ovarian weight associated with the increase in follicular number. Paired ovaries contained a similar number of small and medium follicles, and significant positive correlations were observed between them (r>0.6, P<0.0001). There were significant positive correlations between the weight of OCC and the number of small and medium follicles in paired ovaries (r>0.4, P<0.0001). These results suggest that 1) the weight of an ovary reflects the potential of the ovary to produce antral follicles, and 2) a rough estimation of follicular population might be possible by using the weight of the ovary contralateral to CL in heifers.     

Treatment of Metastatic Equine Melanoma with a Plasmid DNA Vaccine Encoding Streptococcus Pyogenes EMM55 Protein

A 19-year-old castrated male Arab/Quarter horse presented with an extensive history of cutaneous metastatic melanoma. Over a period of 8 months, a total of 8 doses of plasmid DNA vaccine expressing the Streptococcus pyogenes emm55 gene (pAc/emm55) were administered intratumorally at 300 μg/dose via a needless injector. Upon completion of the vaccination protocol, the size of the injected lesions, on average, were reduced by 40.3% from the initial size measurements. Lesions that were not injected were reduced by 47.6%. The overall reduction in total tumor burden was 42.3%. Tumor regression was also associated with the augmentation of antimelanoma IgG antibody response, thus implying that an induction of an effective antimelanoma response would be of great advantage in the management of equine melanoma.     

Effects of ammonia and hydrogen sulfide on physical and biochemical properties of the claw horn of Holstein cows

The effects of ammonia and hydrogen sulfide on the physical and biochemical properties of the claw horn of Holstein cows were evaluated. Significant (P < 0.05, 0.01) decreases in hardness and elasticity were found in claw horns soaked in ammonia (NH₃) and hydrogen sulfide (H₂S) solutions compared with those that were soaked in water for 12, 24, and 48 h. Water absorption rate, as a indicator of permeability barrier function, increased significantly (P < 0.05) over time during the soaking period and was found to be dependent on the concentrations of NH₃ and H₂S in the solutions. The contents of ceramide, the main lipid component for the permeability barrier system of the stratum corneum, were significantly decreased in claw horns soaked in NH₃ and H₂S solutions compared with the values before soaking. Quantities of eluted protein released from claw horns treated with NH₃ and H₂S solutions were approximately 20 times and 30 to 40 times greater than those released from claw horns treated with water alone. Interestingly, the quantities of cytokeratin 10, the main cytoskeletal protein of the stratum corneum, eluted from claw horns treated with NH₃ and H₂S solutions were markedly greater than the quantity released from horns soaked in water. Our results suggest that abnormal changes in the physical property of claw horn caused by NH₃ and H₂S treatment are due to disruption of the biochemical property of the claw horn induced by these chemical agents derived from slurry.     

Connected to death: the (unexpurgated) mitochondrial pathway of apoptosis

The mitochondrial pathway of apoptosis in vertebrates is dependent on the process of mitochondrial outer membrane permeabilization (MOMP), which leads to the release of proteins from the mitochondrial intermembrane space into the cytosol. "Upstairs" of this event are the Bcl-2 family proteins that regulate and mediate MOMP; "downstairs" is the activation of caspases that orchestrate the dismantling of the cell. In the Connections Map database at Science's Signal Transduction Knowledge Environment (STKE), the pathways that define the mitochondrial pathway of apotosis are illustrated, with the bulk of control occurring "upstairs" of MOMP.     

A retrotransposon-based probe for fingerprinting and evolutionary studies in rice (Oryza sativa)

A genomic DNA fragment (pAA7-2) amplified by a random amplified polymorphic DNA primer from the rice cultivar IR68 was used to assess the genetic variation and genetic relationships among the species of genus Oryza. A Southern hybridization experiment of diverse upland rice accessions using a single restriction enzyme HindIII generated unique DNA fingerprint for each accession. The differential hybridization pattern reflecting the copy number variation of pAA7-2 in a collection of wild species and cultivated species of rice provided insight about the genetic relationships among them. All AA genome species exhibited clear banding pattern suggesting presence of fewer copies of this sequence. Strongest hybridization signal was obtained in species belonging to BB, CC, GG, BBCC, CCDD genomes, whereas weakest hybridization signal was visible in EE, FF, and HHJJ genome species. Oryza brachyantha was the most divergent species. Clear difference in banding pattern was evident between Oryza schlechteri and Oryza coarctata belonging to HHKK genome. Although pAA7-2 had no repetitive sequences often associated with hypervariable loci, homology to a putative unclassified expressed retrotransposon distributed over several rice chromosomes was responsible for the complex banding patterns. There were more sites homologous to pAA7-2 sequence in corn and sorghum genome compared with the rice genome. The study demonstrates the potential of pAA7-2 as a powerful molecular tool for DNA fingerprinting, genetic diversity, phylogenetic, and evolutionary studies in Oryza sativa and its wild relatives and other grasses.     

Plasticity of reproductive allocation of a woody species (Ulex europaeus) in response to variation in resource availability

Context

While many woody perennials grow and reproduce in varying environments, their ability to modify their reproductive allocation under varying resource availability is unclear.

Aims

This study aimed to demonstrate the occurrence of plasticity of reproductive allocation in a pioneer woody species (Ulex europaeus).

Methods

We studied seed production in 144 plants under different irradiance and population densities. We measured their basal area, their whole shoot biomass and photosynthetic biomass, and their reproductive output (number of fruits per individual and number of seeds per fruit).

Results

We found that newly produced photosynthetic biomass was influenced by environmental variation, which in turn determined its reproductive output. In addition, in low light conditions investment in reproduction was more reduced than investment in growth indicating plasticity of reproductive allocation.

Conclusion

These results provide the first evidence for plasticity of reproductive allocation of a woody plant. It may lead to the ability of this pioneer species to survive and to continue to reproduce even at low rates in non-optimal shady habitats and to maintain a non-empty seed bank in forest systems with long unfavourable periods between two disturbances.