Mice with cardiac-specific sequestration of the beta-subunit of the L-type calcium channel

The beta subunit of the L-type voltage-dependent calcium channel modifies the properties of the channel complex by both allosteric modulation of the alpha1 subunit function and by chaperoning the translocation of the alpha1 subunit to the plasma membrane. The goal of this study was to investigate the functional effect of changing the in vivo stoichiometry between the alpha1 and beta subunits by creating a dominant negative expression system in a transgenic mouse model. The high affinity beta subunit-binding domain of the alpha1 subunit was overexpressed in a cardiac-specific manner to act as a beta subunit trap. We found that the predominant beta isoform was located primarily in the membrane bound fraction of heart protein, whereas the beta1 and beta3 were mostly cytosolic. There was a significant diminution of the amount of beta2 in the membrane fraction of the transgenic animals, resulting in a decrease in contractility of the heart and a decrease in L-type calcium current density in the myocyte. However, there were no distinguishable differences in beta1 and beta3 protein expression levels in the membrane bound fraction between transgenic and non-transgenic animals. Since the beta1 and beta3 isoforms only make up a small portion of the total beta subunit in the heart, slight changes in this fraction are not detectable using Western analysis. In contrast, beta1 and beta3 in skeletal muscle and brain, the predominant isoforms in these tissues, respectively, are membrane bound.     

Participation of transfused bone marrow cells in reparative osteohistogenesis

The participation of skeletal tissue cell precursors in the repairing regeneration of bone tissue was studied. Bone marrow was taken from donor animals--mice of C57Bl/6-TgN(ACTbGFP) 1 Osb line (The Jackson Laboratory Bar Harbor ME USA line). Nucleated cell fraction was isolated by centrifugation on a density percoll gradient. Recipient mice C57Bl/6 line were irradiated by 7.0-7.5 Gr dose. Intravenous infusion of donor cells and osteoclasts of tibia was done after irradiation of recipient mice. Histological preparations of bone regenerate tissues were studied on 15, 30, and 60 days by confocal microscopy. Donor cells were found as skeletal tissue precursors into periost, endost, bone marrow, and as differentiated cells of newborn tissue of regenerate--osteoblasts, osteocytes, chondrocytes. The data obtained indicate that part of donor bone marrow cells are able to progressive differentiation under recipient bone fractures.     

Genomic divergence of zebu and taurine cattle identified through high-density SNP genotyping

Background

Natural selection has molded evolution across all taxa. At an arguable date of around 330,000 years ago there were already at least two different types of cattle that became ancestors of nearly all modern cattle, the Bos taurus taurus more adapted to temperate climates and the tropically adapted Bos taurus indicus. After domestication, human selection exponentially intensified these differences. To better understand the genetic differences between these subspecies and detect genomic regions potentially under divergent selection, animals from the International Bovine HapMap Experiment were genotyped for over 770,000 SNP across the genome and compared using smoothed F_ST. The taurine sample was represented by ten breeds and the contrasting zebu cohort by three breeds.

Results

Each cattle group evidenced similar numbers of polymorphic markers well distributed across the genome. Principal components analyses and unsupervised clustering confirmed the well-characterized main division of domestic cattle. The top 1% smoothed F_ST, potentially associated to positive selection, contained 48 genomic regions across 17 chromosomes. Nearly half of the top F_ST signals (n = 22) were previously detected using a lower density SNP assay. Amongst the strongest signals were the BTA7:~50 Mb and BTA14:~25 Mb; both regions harboring candidate genes and different patterns of linkage disequilibrium that potentially represent intrinsic differences between cattle types. The bottom 1% of the smoothed F_ST values, potentially associated to balancing selection, included 24 regions across 13 chromosomes. These regions often overlap with copy number variants, including the highly variable region at BTA23:~24 Mb that harbors a large number of MHC genes. Under these regions, 318 unique Ensembl genes are annotated with a significant overrepresentation of immune related pathways.

Conclusions

Genomic regions that are potentially linked to purifying or balancing selection processes in domestic cattle were identified. These regions are of particular interest to understand the natural and human selective pressures to which these subspecies were exposed to and how the genetic background of these populations evolved in response to environmental challenges and human manipulation.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-14-876) contains supplementary material, which is available to authorized users.     

Assessing signatures of selection through variation in linkage disequilibrium between taurine and indicine cattle

Background

Signatures of selection are regions in the genome that have been preferentially increased in frequency and fixed in a population because of their functional importance in specific processes. These regions can be detected because of their lower genetic variability and specific regional linkage disequilibrium (LD) patterns.

Methods

By comparing the differences in regional LD variation between dairy and beef cattle types, and between indicine and taurine subspecies, we aim at finding signatures of selection for production and adaptation in cattle breeds. The VarLD method was applied to compare the LD variation in the autosomal genome between breeds, including Angus and Brown Swiss, representing taurine breeds, and Nelore and Gir, representing indicine breeds. Genomic regions containing the top 0.01 and 0.1 percentile of signals were characterized using the UMD3.1 Bos taurus genome assembly to identify genes in those regions and compared with previously reported selection signatures and regions with copy number variation.

Results

For all comparisons, the top 0.01 and 0.1 percentile included 26 and 165 signals and 17 and 125 genes, respectively, including TECRL, BT.23182 or FPPS, CAST, MYOM1, UVRAG and DNAJA1.

Conclusions

The VarLD method is a powerful tool to identify differences in linkage disequilibrium between cattle populations and putative signatures of selection with potential adaptive and productive importance.     

Impact of temperature on Na2Sr(PO4)F:Eu3+ phosphor

In this article, we report the synthesis of Na₂Sr_1‐x(PO₄)F:Eu_x phosphor via a combustion method. The influence of different annealing temperatures on the photoluminescence properties was investigated. The phosphor was excited at both 254 and 393 nm. Na₂Sr_1‐x(PO₄)F:Eu_x³⁺ phosphors emit strong orange and red color at 593 and 612 nm, respectively, under both excitation wavelengths. Na₂Sr_1‐x(PO₄)F:Eu_x³⁺ phosphors annealed at 1050°C showed stronger emission intensity compared with 600, 900 and 1200°C. Moreover, Na₂Sr_1‐x(PO₄)F:Eu_x³⁺ phosphor was found to be more intense when compared with commercial Y₂O₃:Eu³⁺ phosphor. Copyright © 2013 John Wiley & Sons, Ltd.     

Comparative characteristics of the retention of verbal information received by adult subjects in the waking and hypnotic states

Estimation of the amounts of short-term memory in adults in the waking and hypnotic states showed two relationships in its expression. If subjects memorized verbal information in the waking state and were hypnotized after that, their short-term memory was considerably impaired. After the same subjects were awakened again, this form of memory was not improved; moreover, it was further impaired. On the other hand, if adult subjects memorized verbal information in the state of hypnosis (an altered state of consciousness, ASC), their short-term memory remained almost unchanged after they returned to the original waking state.     

Biological activity of electrochemically activated solutions obtained in a diaphragm electrolyser

The biological activity of the catholyte and anolyte of bidistilled water in experiments with the germination of wheat grains in the period from March to May has been studied. The activity of solutions, which was characterized by the grain germination index, was high at the beginning of the period, then it gradually decreased and was equal to zero at the middle of the period; at the end of the period it gradually increased almost to initial values. It has been established that the effectiveness of bidistilled water anolyte was as a rule higher than that of catholyte throughout the observation period. At the beginning and end, the stimulating effect of anolyte was 5-5.5 times greater than that of catholyte. The seasonal changes in the biological activity of M 9 medium catholyte were compared with those of bidistilled water anolyte and catholyte. The stimulating effect of M 9 catholyte was estimated by changes in the growth of E. coli cells. The stimulating effect, which was estimated from an increase in the optical density of cell suspension in the initial period at a cultivation temperature of 20 degrees C was 55-60% relative to control (untreated medium). Then it decreased almost to zero in the middle of the period to increase again approximately to the initial values. The assumption has been made that the physicochemical causes of the influence of catholyte and anolyte of bidistilled water on wheat grains and of the culture medium catholyte on E. coli cells are of different nature.