SummaryWe investigated the myosin expression profile in prostate cancer cell lines and found that Myo1b, Myo9b, Myo10, and Myo18a were expressed at higher levels in cells with high metastatic potential. Moreover, Myo1b and Myo10 were expressed at higher levels in metastatic tumors. Using an siRNA-based approach, we found that knockdown of each myosin resulted in distinct phenotypes. Myo10 knockdown ablated filopodia and decreased 2D migration speed. Myo18a knockdown increased circumferential non-muscle myosin 2A-associated actin filament arrays in the lamella and reduced directional persistence of 2D migration. Myo9b knockdown increased stress fiber formation, decreased 2D migration speed, and increased directional persistence. Conversely, Myo1b knockdown increased numbers of stress fibers but did not affect 2D migration. In all cases, the cell spread area was increased and 3D migration potential was decreased. Therefore, myosins not only act as molecular motors but also directly influence actin organization and cell morphology, which can contribute to the metastatic phenotype.

Androgenesis is highly useful for plant breeding, significantly reducing breeding cycle times, as well as in a wide range of biological research. However, for widespread use this process must be efficient. Despite several decades of research on the phenomenon of androgenesis, many processes involved are obscure and there is much to be understood about androgenesis. One of the problems inherent in androgenesis, and reducing its efficiency, is albinism. This article reviews albinism in barley anthers and microspores in vitro cultures. Of special interest is the fate of plastids throughout androgenesis, which is important at several levels, including the genes responsible for driving the green-to-albino ratios. We also summarize the external factors that reduce the incidence of albino plants that are regenerated via androgenesis.

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Variable efficiency of androgenesis remains a serious problem in many species of cereals. It is still unclear what makes certain genotypes more amenable to androgenesis than others. This study was undertaken to quantify the previously suspected advantage of winter barley genotypes over spring ones with regard to regeneration efficiency in anther culture. The material consisted of 40 barley hybrids originating from Polish breeding companies. The number of androgenic structures per 100 anthers did not differ significantly between analysed groups (119 vs. 152 non-significant), but the average regeneration of green plants per 100 anthers was five times higher in winter genotypes (6.4 vs. 1.3). The incidence of albinism was lower for the winter than for the spring materials (70% vs. 90%), while the rate of spontaneous chromosome doubling was similar in both groups (58% vs. 56%). The results strongly support the notion that winter genotypes are more amenable to androgenesis and this may be a consequence of their better adaptation to stress conditions.

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The paper describes an application of nondestructive volumetric magnetic and ultrasonic techniques for evaluation of the selected mechanical parameter variations of P91 steel having direct influence on its suitability for further use in critical components used in power plants. Two different types of deformation processes were carried out. First, a series of the P91 steel specimens was subjected to creep and second, one to plastic deformation in order to achieve the material with an increasing strain level up to 10%. Subsequently, non-destructive and destructive tests were performed. Magnetic methods based on measurements of magnetoacoustic emission and magnetic hysteresis loop changes as well as the ultrasonic method based on acoustic birefringence measurements, were applied. Finally, the static tensile tests were carried out in order to evaluate the mechanical parameters. It is shown that some relationships between the selected parameters coming from the non-destructive and destructive tests may be formulated.

Makowska K., Oleszczuk S., Zimny J. (2017): The effect of copper on plant regeneration in barley microspore culture. Czech J. Genet. Plant Breed., 53: 17-22.Isolated microspore culture is an excellent system for the production of doubled haploids in many crops, including barley. In a more traditional barley anther culture method copper sulphate is known to enhance plant regeneration. Here we report that one hundred times higher concentration of copper sulphate in the isolated microspore culture of two spring barley genotypes compared to the standard content in the induction medium resulted in a 34% increase of total plant regeneration. Detailed analysis of plant regeneration showed that additional supplementation of copper sulphate increased not only the regeneration of green plants but also proportionately that of albino plants. Hence, the results from two studied genotypes do not support an assumption that the addition of copper reduces albinism in barley microspore culture.