Comparative characterization of mitochondrial nucleoids and of nuclear chromatin of sea urchin embryos

Summary Chromatin and mitochondrial nucleoids of sea urchin embryos were found to have different isopycnic densities in metrizamide gradients. The banding density of nucleoids was constant during development, while there appeared to be alterations in the density profiles of chromatin banded at low ionic strength.     

Metabolomic profiling of wild‐type and mutant soybean root nodules using laser‐ablation electrospray ionization mass spectrometry reveals altered metabolism

The establishment of the nitrogen‐fixing symbiosis between soybean and Bradyrhizobium japonicum is a complex process. To document the changes in plant metabolism as a result of symbiosis, we utilized laser ablation electrospray ionization‐mass spectrometry (LAESI‐MS) for in situ metabolic profiling of wild‐type nodules, nodules infected with a B. japonicum nifH mutant unable to fix nitrogen, nodules doubly infected by both strains, and nodules formed on plants mutated in the stearoyl‐acyl carrier protein desaturase (sacpd‐c) gene, which were previously shown to have an altered nodule ultrastructure. The results showed that the relative abundance of fatty acids, purines, and lipids was significantly changed in response to the symbiosis. The nifH mutant nodules had elevated levels of jasmonic acid, correlating with signs of nitrogen deprivation. Nodules resulting from the mixed inoculant displayed similar, overlapping metabolic distributions within the sectors of effective (fix⁺) and ineffective (nifH mutant, fix^?) endosymbionts. These data are inconsistent with the notion that plant sanctioning is cell autonomous. Nodules lacking sacpd‐c displayed an elevation of soyasaponins and organic acids in the central necrotic regions. The present study demonstrates the utility of LAESI‐MS for high‐throughput screening of plant phenotypes. Overall, nodules disrupted in the symbiosis were elevated in metabolites related to plant defense.     

High variability in the tissue culture response of root-tips of Allium ascalonicum individuals and optimization of the regeneration procedure

This study assessed the shoot regeneration capacity of root-tips isolated from single seed-derived individual plants, obtained from a wild, open-pollinated micropopulation of shallot (Allium ascalonicum). Considerable variation was observed in the regeneration capacities of individual lines, ranging from 0.93 to 100 %, and a mean bud number per root explant between 0.09 and 20.67. One line was found to be superior, and was chosen for protocol optimization, focusing on the 2,4-D/BA ratio, duration of the CI phase and light conditions. The application of the optimized protocol to other lines, selected for their variable regeneration capacities, enhanced the process of regeneration and shortened the time required to obtain healthy plantlets, even in inferior lines. However, highly responsive lines remained superior, indicating that differences at the individual level must not be overlooked. The conditions employed in this study may serve as a base to facilitate the application of molecular breeding methods in shallot.     

Polymorphism of mtDNA regions in brown hare (Lepus europaeus) populations from Vojvodina (Serbia and Montenegro)

It is well known that there is heterogeneity of mitochondrial DNA (mtDNA) within and among natural populations of same species. The polymorphism level of particular regions of mtDNA gives valuable results in detection of population genetic structure. The aim of this paper was to detect polymorphism of three mtDNA regions: cytochrome oxidase I (COI), Control region, and 12S/16S rRNA, by the mtDNA RFLP-PCR method, in three Lepus europaeus populations from Vojvodina province (Serbia and Montenegro). Polymorphism was detected within the two regions, COI and Control region, while 12S/16S rRNA region was monomorphic in all 77 individuals. Eight haplotypes were detected in the brown hare population in Vojvodina, and three were unique for the Srem brown hare population.     

Therapy effect of antiulcer agents on new chronic cysteamine colon lesion in rat

After demonstration that cysteamine induced duodenal lesions in gastrectomized rats, while a number of antiulcer drugs mitigated these lesions, it was shown that one single intrarectal (i.r.) cysteamine application produced severe colon lesions in acute studies in rats. Thus, the further focus was on the protracted effect of cysteamine challenge (400 mg/kg b.w. i.r.) and therapy influence in chronic experiments in female rats. Regularly, cysteamine colon lesions were markedly mitigated by ranitidine (10), omeprazole (10), atropine (10), methylprednisolone (1), sulphasalazine (50; mg/kg), pentadecapeptide BPC 157 (PL-10, PLD-116; 10 microg or 10 ng/kg). Specifically, after 1 or 3 months following initial challenge (cysteamine 400 mg/kg i.r.) in female rat, the therapy [BPC 157 (PL-10, PLD-116 (10.0 microg or 10.0 ng/kg; i.g., i.p., i.r.), ranitidine, omeprazole, atropine, methylprednisolone, sulphasalazine (i.p.)] reversed the protracted cysteamine colon injury: the 1 week-regimen (once daily application) started after 1 month post-cysteamine, as well as the 2 weeks-regimen (once daily application), which started after 3 months. The effect on recidive lesion was also tested. These cysteamine lesions may reappear after stopping therapy (after stopping therapy for 3 weeks at the end of 2-weeks regimen started in 3 months-cysteamine female rats) in sulphasalazine group, while this reappearance is markedly antagonized in pentadecapeptide BPC 157 (PL-10, PLD-116)-rats (cysteamine-colon lesion still substantially low).