Changes of phorbol ester binding sites in rat brain following intracerebroventricular administration of thyrotropin-releasing hormone (TRH): An in vitro macroautoradiographic investigation

We examined the influence of the intracerebroventricular (icv) administration of thyrotropin-releasing hormone (THH) on protein kinase C (PKC) activities in various rat forebrain regions in order to cast light on the mechanism of extra-pituitary non-endocrine physiological actions of TRH in the central nervous system. An in vitro macroautoradiographic method, with [³H]phorbol 12, 13-dibutyrate (PDBu) as the radioactive ligand, was used to investigate quantitative alterations of PKC activities. The optical densities for PDBu binding sites in the striatum and hippocampal formation were significantly increased after the icv administration of TRH, while those in the frontal cortex and septum were unchanged. These findings suggest that TRH may exert some of its non-endocrine functions through striatal and hippocampal neurons which used PKC in their second messenger systems.     

Tamoxifen feeding method is suitable for efficient conditional knockout

The Cre-driver system is used to generate conditional knockout mice. Tamoxifen inducible Cre-driver mice can be used for spatiotemporal knockout by administration of the drug. A major tamoxifen administration is performed by intraperitoneal administration or oral administration. However, these forced administrations may be damaging to mice. Herein, we have demonstrated an improved method of administering tamoxifen with powdered food to mice. A mouse line expressing the tamoxifen-inducible Cre gene was used ubiquitously in this experiment to evaluate the efficiency of Cre recombination in the whole body. Our method also achieved efficient recombination without causing injury to mice. The X-gal staining intensity of the feeding method was equivalent to that of the intraperitoneal administration method. Furthermore, this method can be used for recombination before birth, or during the fetal period. We recommend researchers to employ this feeding method to administer tamoxifen to minimize the risk of injury to mice.     

Expression of Activin Receptor-like Kinase 7 in Adipose Tissues

The tissue distribution of activin receptor-like kinase 7 (Alk7) expression, the signaling ability of Alk7 variants, and Alk7 expression in response to β₃-adrenergic receptor activation were examined. Expression levels of Alk7 varied greatly among tissues but were highest in white adipose tissue and brown adipose tissue. In addition to full-length Alk7 (Alk7-v1), Alk7-v3, an Alk7 variant, was expressed in adipose tissues, brain, and ovary. Nodal transmits signals via Alk7 in cooperation with its coreceptor, Cripto. Evaluation of the ability of Alk7 variants to confer Nodal signaling using luciferase-based reporter assays showed that Alk7-v3 does not transmit Nodal-Cripto-mediated signals. Expression of Alk7 was down-regulated in brown but not in white adipose tissue treated with CL316,243, a β₃-adrenergic receptor agonist. These results suggest involvement of Alk7 in modulation of metabolism in the adipose tissues in response to β₃-adrenergic receptor activation.     

Classification of 3D structural character of RNA by hydrogen bond and base stacking.

We are developing a computational system to classify RNA structures by its structural character. Here, an improved grouping algorithm was introduced to the system and the base-stacking pattern (BSP) is used as a criterion for the classification in addition to hydrogen-bond pattern (HBP). 279 conformers of 15 mer RNA hairpin were classified into 89 and 36 groups by HBP and BSP, respectively, suggesting that HBP represents conformational character better than BSP.     

Preparation and regeneration of protoplasts of three fungi of Boletaceae

Protoplasts of three fungi of Boletaceae,Suillus luteus, S. grevillei, andBoletinus cavipes, were prepared with yields of 45, 8.0, and 1.8×10⁷/g fresh mycelia under the optimal conditions, respectively. Nucleate protoplasts accounted for 42% of the whole preparation ofS. luteus and 32% of that ofS. grevillei, and 21% of the nucleate protoplasts ofS. luteus and 35% of those ofS. grevillei possesed two nuclei. Regeneration efficiency of protoplasts was 0.4% forS. luteus and 0.05% forS. grevillei. The regeneration ofB. cavipes protoplasts was also confirmed. Optimal conditions for regeneration were determined. Addition of gellan gum instead of agar to the medium and activated charcoal treatment of agar medium increased the regeneration efficiency significantly.     

Parasitic Wasps Learn and Report Diverse Chemicals with Unique Conditionable Behaviors

Chemical Senses, 28, 545–549 Regrettably, an error occurred in Figure 3 of this     

Effects of dynein inhibitor on the number of motor proteins transporting synaptic cargos

Synaptic cargo transport by kinesin and dynein in hippocampal neurons was investigated by noninvasively measuring the transport force based on nonequilibrium statistical mechanics. Although direct physical measurements such as force measurement using optical tweezers are difficult in an intracellular environment, the noninvasive estimations enabled enumerating force-producing units (FPUs) carrying a cargo comprising the motor proteins generating force. The number of FPUs served as a barometer for stable and long-distance transport by multiple motors, which was then used to quantify the extent of damage to axonal transport by dynarrestin, a dynein inhibitor. We found that dynarrestin decreased the FPU for retrograde transport more than for anterograde transport. This result indicates the applicability of the noninvasive force measurements. In the future, these measurements may be used to quantify damage to axonal transport resulting from neuronal diseases, including Alzheimer’s, Parkinson’s, and Huntington’s diseases.