Actin-Microtubule Interaction in Plants

Interactions between actins and microtubules play an important role in many fundamental cellular processes in eukaryotes. Although several studies have shown actins and microtubules to be involved in specific cellular activities, little is known about how actins and microtubules contribute together to a given process. Preprophase band formation, which plays an essential role in plant division site determination, is a cellular process that lends itself to studies of actin-microtubule interactions and how they contribute to important cellular functions. Recently, we have analyzed microtubule-associated microfilaments during preprophase band formation in onion cotyledon epidermal cells using a combination of high-pressure freezing/freeze substitution and electron tomography. Quantitative analysis of our electron tomography data showed that relatively short single microfilaments form bridges between two adjacent microtubules in the process of narrowing of the preprophase microtubule band. Two types of microtubule-microfilament-microtubule connections are observed, and these microfilament-microtubule interactions suggest a direct role of F-actins in microtubule bundling. Based on these observations, we discuss how different actin-microtubule linkers might contribute to preprophase band narrowing and to other changes in microtubule organization in plant cells

129 Xe NMR of xenon trapped in fully dehydrated mesoporous silica

129Xe NMR spectra of natural abundant xenon gas trapped in fully dehydrated mesoporous materials with pore sizes smaller than 2 nm in diameter were observed under atmospheric pressure in the temperature range between 168 and 373 K. The average pore diameters of the materials studied in this paper were 0.5, 1 and about 2 nm for molecular sieves 5A and 13X and synthesized mesoporous silica, respectively. The samples were fully dehydrated using an ultra-high vacuum (UHV) system and xenon gas was introduced with the sample pre-cooled to 168 K just above the boiling point of xenon. The 129Xe NMR spectra were observed as a function of increasing temperature and the 129Xe shift were observed at each temperature for the three samples under atmospheric pressure. The behaviors of xenon atoms in small pores observed in equilibrium states can provide important information on relationships between the pore structure and 129Xe chemical shift

An Unusual Case of Multicentric Castleman's Disease, Complicated by Pleural Effusion

Article信州医学雑誌 65(1): 51-56(2017)journal articl

Efficient generation of nitrogen-vacancy center inside diamond with shortening of laser pulse duration

We investigated the effect of laser pulse duration on nitrogen-vacancy (NV) center generation inside a single crystal diamond. We compared pulse durations of 40 fs (femtosecond laser) and 1 ps (picosecond laser). We found that in both cases, ensemble NV centers could be generated inside the diamond. However, the maximum photoluminescence intensity of the NV center without graphitization for the 40 fs duration was higher than that for the 1 ps duration. This indicated that the femtosecond laser was harder to graphitize diamond and could generate more NV centers without graphitization. This difference may be due to the difference in the photo-absorption process and the resulting lattice dynamics

Dividing without centrioles: innovative plant microtubule organizing centres organize mitotic spindles in bryophytes, the earliest extant lineages of land plants

Triple staining of γ-tubulin, microtubules, and nuclei reveal that three types of MTOCs initiate spindles in bryophytes. Polar organizers in liverworts and plastid MTOCs in hornworts are unique and nuclear envelope MTOCs in mosses appear like those in seed plants

Preparation and Observation of Fresh-frozen Sections of the Green Fluorescent Protein Transgenic Mouse Head

Hard tissue decalcification can cause variation in the constituent protein characteristics. This paper describes a method of preparating of frozen mouse head sections so as to clearly observe the nature of the constituent proteins. Frozen sections of various green fluorescent protein (GFP) transgenic mouse heads were prepared using the film method developed by Kawamoto and Shimizu. This method made specimen dissection without decalcification possible, wherein GFP was clearly observed in an undamaged state. Conversely, using the same method with decalcification made GFP observation in the transgenic mouse head difficult. This new method is suitable for observing GFP marked cells, enabling us to follow the transplanted GFP marked cells within frozen head sections