Detecting local establishment strategies of wild cherry (Prunus avium L.)

Backround  

P. avium, a pioneer tree species that colonizes early forest successional stages, is assumed to require an effective strategy allowing stably repeatable rounds of local establishment, dispersal and local extinction. Consequently, the early replacement of cherry by climax tree species makes the establishment of several local generations very unlikely, especially in central European continuous cover forests. This has to be seen in connection with the mixed reproduction system involving asexual reproduction as a complementary adaptational strategy. Tests of the local establishment of wild cherry must therefore consider the possibility of first generation establishment via seedling recruitment potentially followed by an asexual generation (root suckering). Successful establishment can therefore be determined only among adult individuals with the option of detecting vegetative reproduction at these stages. To test the implied suggestion about local establishment strategies of wild cherry, nuclear microsatellites were used to analyse patterns of asexual propagation among adult stages that have been subjected to one of two major types of forest management. These management types, the historical "coppice with standards system" (CWS) and the "high forest system" (HFS), can be reasonably assumed to have affected the reproduction system of P. avium.     

Isolation of a novel mutant gene for soil-surface rooting in rice (Oryza sativa L.)

Background

Root system architecture is an important trait affecting the uptake of nutrients and water by crops. Shallower root systems preferentially take up nutrients from the topsoil and help avoid unfavorable environments in deeper soil layers. We have found a soil-surface rooting mutant from an M₂ population that was regenerated from seed calli of a japonica rice cultivar, Nipponbare. In this study, we examined the genetic and physiological characteristics of this mutant.

Results

The primary roots of the mutant showed no gravitropic response from the seedling stage on, whereas the gravitropic response of the shoots was normal. Segregation analyses by using an F₂ population derived from a cross between the soil-surface rooting mutant and wild-type Nipponbare indicated that the trait was controlled by a single recessive gene, designated as sor1. Fine mapping by using an F₂ population derived from a cross between the mutant and an indica rice cultivar, Kasalath, revealed that sor1 was located within a 136-kb region between the simple sequence repeat markers RM16254 and 2935-6 on the terminal region of the short arm of chromosome 4, where 13 putative open reading frames (ORFs) were found. We sequenced these ORFs and detected a 33-bp deletion in one of them, Os04g0101800. Transgenic plants of the mutant transformed with the genomic fragment carrying the Os04g0101800 sequence from Nipponbare showed normal gravitropic responses and no soil-surface rooting.

Conclusion

These results suggest that sor1, a rice mutant causing soil-surface rooting and altered root gravitropic response, is allelic to Os04g0101800, and that a 33-bp deletion in the coding region of this gene causes the mutant phenotypes.     

A simple specimen preparation method for histopathological evaluation of vestibular organs

Vestibular organs consist of the maculae staticae, which are located in both the utricle and saccule, as well as the semicircular ducts and their ampullas. There have been no reports on specimen preparation methods for vestibular organs, including maculae staticae or semicircular ducts. In this study, we investigated highly reproducible methods of preparing vestibular organ specimens for histopathological examinations. We established a method that allows researchers to observe the utricle and saccule, including otoliths, the ampulla of a semicircular duct, and parts of semicircular ducts. This highly reproducible method is useful for histopathological analysis of mice with symptoms of abnormal equilibrium caused by medical toxicity and genetic modification.     

Pharmacokinetics in plasma and alveolar regions of a healthy calf intramuscularly administered a single dose of orbifloxacin

This study analyzed the pharmacokinetics of orbifloxacin (OBFX) in plasma, and its migration and retention in epithelial lining fluid (ELF) and alveolar cells within the bronchoalveolar lavage fluid (BALF). Four healthy calves received a single dose of OBFX (5.0 mg/kg) intramuscularly. Post-administration OBFX dynamics were in accordance with a non-compartment model, including the absorption phase. The maximum concentration (C_max) of plasma OBFX was 2.2 ± 0.1 μg/ml at 2.3 ± 0.5 hr post administration and gradually decreased to 0.3 ± 0.2 μg/ml at 24 hr following administration. The C_max of ELF OBFX was 9.3 ± 0.4 μg/ml at 3.0 ± 2.0 hr post administration and gradually decreased to 1.2 ± 0.1 μg/ml at 24 hr following administration. The C_max of alveolar cells OBFX was 9.3 ± 2.9 μg/ml at 4.0 hr post administration and gradually decreased to 1.1 ± 0.2 μg/ml at 24 hr following administration. The half-life of OBFX in plasma, ELF, and alveolar cells were 6.9 ± 2.2, 7.0 ± 0.6, and 7.8 ± 1.6 hr, respectively. The C_max and the area under the concentration-time curve for 0–24 hr with OBFX were significantly higher in ELF and alveolar cells than in plasma (P<0.05). These results suggest that OBFX is distributed and retained at high concentrations in ELF and alveolar cells at 24 hr following administration. Hence, a single intramuscular dose of OBFX (5.0 mg/kg) may be an effective therapeutic agent against pneumonia.     

Impacts of forest drainage improvement on stream biota: A multisite BACI-experiment

Impacts of forestry have been described in many studies, with a strong focus on changes in run-off water quality. Biological responses to forest drainage and the efficiency of commonly used water protection methods remain largely unknown, however. We used a six-year replicated before-after-control-impact (BACI) field experiment to assess the effects of forest drainage improvement works (ditch cleaning; digging of supplementary ditches) on water chemistry, sedimentation, brown trout egg mortality and macroinvertebrate community composition in six headwater streams in Northern Finland. Standard water protection methods (ditch break combined with sedimentation pit) were used to reduce fine sediment (<1.0 mm) loading into the streams. Six artificial spawning sites were constructed in each stream, three downstream (treatments) and three upstream (controls) of the drainage areas. Sediment loading did not increase after forest drainage, and no changes were detected in water quality. Brown trout egg mortality rate increased after drainage works, but more so in the upstream controls than downstream treatment sections, and only in smaller (watershed <6.25 km²) streams. All macroinvertebrate metrics (e.g. total macroinvertebrate diversity and density) decreased significantly through time. However, these responses were observed in both control and treatment sections, and could not have been caused by the drainage works directly but were rather related to inter-annual variability in precipitation and discharges. Our results thus highlight the importance of placing results from local monitoring studies in a regional context.     

Bayesian Spatial Point Process Modeling of Line Transect Data

This paper develops a Bayesian approach for spatial inference on animal density from line transect survey data. We model the spatial distribution of animals within a geographical area of interest by an inhomogeneous Poisson process whose intensity function incorporates both covariate effects and spatial smoothing of residual variation. Independently thinning the animal locations according to their estimated detection probabilities results into another spatial Poisson process for the sightings (the observations). Prior distributions are elicited for all unknown model parameters. Due to the sparsity of data in the application we consider, eliciting sensible prior distributions is important in order to get meaningful estimation results. A reversible jump Markov Chain Monte Carlo (MCMC) algorithm for simulation of the posterior distribution is developed. We present results for simulated data and a real data set of minke whale pods from Antarctic waters. The main advantages of our method compared to design-based analyses are that it can use data arising from sources other than specifically designed surveys and its ability to link covariate effects to variation of animal density. The Bayesian paradigm provides a coherent framework for quantifying uncertainty in estimation results.     

Efficacy of leflunomide for treatment of refractory inflammatory colorectal polyps in 15 Miniature Dachshunds

Inflammatory colorectal polyp (ICRP), common in miniature dachshunds, presents with hematochezia, tenesmus and mucoid feces. Although an 80% response rate has been reported when treated with prednisolone and cyclosporine, effective treatment is needed for the remaining 20% of ICRP dogs. Leflunomide is an immunosuppressive drug reported as effective in several immune-mediated diseases. In the present study, we retrospectively evaluated the efficacy and adverse effects of leflunomide in 15 ICRP dogs that were refractory to treatment with prednisolone and cyclosporine. Treatment efficacy was assessed by endoscopy, clinical symptoms and rectal palpation. Adverse effects were determined by clinical symptoms and blood testing during follow-up. The leflunomide treatment response rate was 93.3%. The median dosage of leflunomide and the median response time were 3 mg/kg (range: 1.7–4.0 mg/kg) and 35 days (range: 20–119 days), respectively. Adverse effects observed included lethargy (3 dogs), anorexia (1 dog), respiratory symptoms (1 dog), leukocytopenia (2 dogs), thrombocytopenia (1 dog), anemia (1 dog) and liver enzyme elevation (8 dogs). Most of the adverse effects improved with symptomatic treatment and leflunomide discontinuation or dosage reduction. In conclusion, leflunomide treatment is effective in ICRP dogs refractory to treatment with prednisolone and cyclosporine. Because several adverse effects were observed, close monitoring is needed during leflunomide treatment follow-up.     

Establishment of ku70-deficient lung epithelial cell lines and their hypersensitivity to low-dose x-irradiation

In clinical situations, cellular resistance to chemotherapy and radiotherapy is a significant component of tumor treatment failure. The DNA repair protein Ku70 is a key contributor to chemoresistance to anticancer agents, e.g., etoposide and bleomycin, or radioresistance. Ku70 plays a key role as a sensor of DNA double-strand breaks (DSBs) induced following exposure to ionizing radiation as well as treatment with some chemotherapeutic drugs. The responses of different organs to radiation vary widely and likely depend on the cell population in the organs. However, it is not clear whether Ku70 plays a role in the low-dose radioresistance of lung epithelial cells. In this study, we established Ku70-deficient epithelial cell lines from murine lungs lacking Ku70. Ku70-/- lung epithelial cells exhibited reduced Ku80 expression. Moreover, Ku70-/- lung epithelial cells were more sensitive than controls (Ku70+/- lung epithelial cells) to low-dose X-irradiation (< 0.5 Gy). We also found that consistent with the Ku70 function as a sensor of DSBs, Ku70 mainly localized in the nuclei of murine lung epithelial cells. These findings clearly indicate that Ku70 plays a key role in regulation of the Ku80 expression level in and the radioresistance of lung epithelial cells. Our data also suggest that these cell lines might be useful not only for study of Ku70 functions and the DSB repair pathway, but also for study of the molecular mechanism underlying the sensitivity to chemotherapeutic drugs and radiation in lung epithelial cells.