Genomewide scan and fine-mapping linkage studies in four European samples with bipolar affective disorder suggest a new susceptibility locus on chromosome 1p35-p36 and provides further evidence of loci on chromosome 4q31 and 6q24

We present the findings of a large linkage study of bipolar affective disorder (BPAD) that involved genomewide analysis of 52 families (448 genotyped individuals) of Spanish, Romany, and Bulgarian descent and further fine mapping of the 1p34-p36, 4q28-q31, and 6q15-q24 regions. An additional sample of 56 German families (280 individuals) was included for this fine-mapping step. The highest nonparametric linkage scores obtained in the fine mapping were 5.49 for 4q31 and 4.87 for 6q24 in the Romany families and 3.97 for 1p35-p36 in the Spanish sample. MOD-score (LOD scores maximized over genetic model parameters) analysis provided significant evidence of linkage to 4q31 and at least borderline significance for the 1p and 6q regions. On the basis of these results and previous positive research findings, 4q31 and 6q24 should now be considered confirmed BPAD susceptibility loci, and 1p35-p36 is proposed as a new putative locus that requires confirmation in replication studies.     

Numbers of antral follicles during follicular waves in cattle: evidence for high variation among animals, very high repeatability in individuals, and an inverse association with serum follicle-stimulating hormone concentrations

The extent, causes, and physiological significance of the variation in number of follicles growing during ovarian follicular waves in human beings and cattle are unknown. Therefore, the present study examined the variability and repeatability in numbers of follicles 3 mm or greater in diameter during the follicular waves in bovine estrous cycles, and we determined if the variation in number of follicles during waves was associated with alterations in secretion of FSH, estradiol, inhibin, and insulin-like growth factor I (IGF-I). Dairy cattle were subjected to twice-daily ultrasound analysis to count total number of antral follicles 3 mm or greater in diameter throughout 138 different follicular waves. In another study, blood samples were taken at frequent intervals from cows that consistently had low or very high numbers of follicles during waves and were subjected to immunoassays. Results indicate the following: First, despite an approximately sevenfold variation in number of follicles during waves among animals and marked differences in age, stage of lactation, and season of the year, a very highly repeatable (0.95) number of follicles 3 mm or greater in diameter is maintained during the ovulatory and nonovulatory follicular waves of individuals. Second, variation in number of follicles 3 mm or greater in diameter during waves and the inverse association of number of follicles during waves with FSH are not directly explained by alterations in the patterns of secretion of estradiol, inhibin, or IGF-I. Third, ovarian ultrasound analysis can be used reliably by investigators to identify cattle that consistently have low or high numbers of follicles during waves, thus providing a novel experimental model to determine the causes and physiological significance of the high variation in antral follicle number during follicular waves among single-ovulating species, such as cattle or humans.     

Na+/H+ exchangers (NHE1-3) have similar turnover numbers but different percentages on the cell surface

NHE1, NHE2, andNHE3 are well-characterized cloned members of the mammalianNa⁺/H⁺exchanger (NHE) gene family. Given the specialized function and regulation of NHE1, NHE2, and NHE3, we compared basal turnover numbersof NHE1, NHE2, and NHE3 measured in the same cell system: PS120fibroblasts lacking endogenous NHEs. NHE1, NHE2, and NHE3 were epitopetagged with vesicular stomatitis virus glycoprotein (VSVG). Thefollowing characteristics were determined on the same passage of cellstransfected with NHE1V, NHE2V, or NHE3V:1) maximal reaction velocity(V_max) by²²Na⁺uptake and fluorometery, 2) totalamount of NHE protein by quantitative Western analysis with internalstandards of VSVG-tagged maltose-binding protein, and3) cell surface expression by cellsurface biotinylation. Cell surface expression (percentage of totalNHE) was 88.8 ± 3.5, 64.6 ± 3.3, 20.0 ± 2.6, and 14.0 ± 1.3 for NHE1V, 85- and 75-kDa NHE2V, and NHE3V, respectively. Despitethese divergent cell surface expression levels, turnover numbers forNHE1, NHE2, and NHE3 were similar (80.3 ± 9.6, 92.1 ± 8.6, and99.2 ± 9.1 s¹, whenV_max wasdetermined using ²²Na uptake at22°C and 742 ± 47, 459 ± 16, and 609 ± 39 s¹ whenV_max wasdetermined using fluorometry at 37°C). These data indicate that, inthe same cell system, intrinsic properties that determine turnovernumber are conserved among NHE1, NHE2, and NHE3.

     

Development of otoconia in the embryonic chick (Gallus domesticus)

In the chick (Gallus domesticus) embryo, otoconium formation started first over the macula sacculi around the 4th day of incubation, and a day later over the macula utriculi. It was determined that each otoconium formed as a result of the segmentation of the immature otolithic membrane, and that the calcium responsible for otoconium calcification was incorporated into the organic matrix of each otoconium in the form of small electron-dense granules (20-150 nm in diameter). The presence of calcium in these granules was confirmed by histochemical staining with osmic-potassium pyroantimonate, by EDTA chelation, and by X-ray microanalysis under the electron microscope.     

Circadian gene methylation profiles are associated with obesity,metabolic disturbances and carbohydrate intake

The circadian clock regulates the daily rhythms of several physiological and behavioral processes. Disruptions in clock genes have been associated with obesity and related comorbidities. This study aimed to analyze the association of DNA methylation signatures at circadian rhythm pathway genes with body mass index (BMI), metabolic profiles and dietary intakes. DNA methylation profiling was determined by microarray in white blood cells from 474 adults from the Methyl Epigenome Network Association (MENA) project. Kyoto Encyclopedia of Genes and Genomes database was used to identify the genes integrating the circadian rhythm pathway. Network enrichment analyses were performed with the PathDIP platform. Associations between circadian methylation patterns with anthropometric measurements, the metabolic profile, clinical data and dietary intakes were analyzed. DNA methylation patterns of nine CpG sites at six circadian rhythm pathway genes were strongly correlated with BMI (false discovery rates <0.0001). These CpGs encompassed cg09578018 (RORA), cg20406576 (PRKAG2), cg10059324 (PER3), cg01180628 (BHLHE40), cg23871860 (FBXL3), cg16964728 (RORA), cg14129040 (CREB1), cg07012178 (PRKAG2) and cg24061580 (PRKAG2). Interestingly, network enrichment analyses revealed that the six BMI-associated genes statistically contributed to the regulation of the circadian rhythm pathway (p = 1.9E-10). In addition, methylation signatures at cg09578018 (RORA), cg24061580 (PRKAG2), cg01180628 (BHLHE40) and cg10059324 (PER3) also correlated with insulin resistance (p < 0.0001) and mean arterial blood pressure (p < 0.0001). Furthermore, relevant correlations (p < 0.05) between methylation at cg09578018 (RORA) and cg01180628 (BHLHE40) with total energy and carbohydrate intakes were found. This investigation revealed potential associations of DNA methylation profiles at circadian genes with obesity, metabolic disturbances and carbohydrate intake, with potential impact on weight homeostasis.     

11-Beta hydroxysteroid dehydrogenase type 2 expression in white adipose tissue is strongly correlated with adiposity

Glucocorticoid action within the cells is regulated by the levels of glucocorticoid receptor (GR) expression and two enzymes, 11-beta hydroxysteroid dehydrogenase type 1 (11betaHSD1), which converts inactive to active glucocorticoids, and 11-beta hydroxysteroid dehydrogenase type 2 (11betaHSD2), which regulates the access of active glucocorticoids to the receptor by converting cortisol/corticosterone to the glucocorticoid-inactive form cortisone/dehydrocorticosterone. Male Wistar rats developed obesity by being fed a high-fat diet for 56 days, and GR, 11betaHSD1 and 11betaHSD2 gene expression were compared with control-diet fed animals. Gene expression analysis of 11betaHSD1, 11betaHSD2 and GR were performed by RT-PCR in subcutaneous and retroperitoneal adipose tissue. High-fat fed animals overexpressed 11betaHSD2 in subcutaneous but not in retroperitoneal fat. Interestingly, mRNA levels strongly correlated in both tissues with different parameters related to obesity, such as body weight, adiposity and insulin resistance, suggesting that this gene is a reliable marker of adiposity in this rat model of obesity. Thus, 11betaHSD2 is expressed in adipose tissue by both adipocytes and stromal-vascular cells, which suggests that this enzyme may play an important role in preventing fat accumulation in adipose tissue.     

Plant functional diversity in tropical Andean páramos

ABSTRACT

Background: Tropical high mountains present extreme daily temperature variations, frequent high air evaporative demands and seasonal differences in soil water availability. Plants have adapted to these conditions through different avoidance-tolerance mechanisms. This review focuses on plant-growth forms and their adaptive strategies.

Aims: This integrated review of páramo plant traits aims at contributing to understanding the functioning of plant-growth forms and their significance on ecosystem properties under environmental climate and land-use changes.

Methods: Plant responses are presented along avoidance-tolerance gradients considering three main aspects: freezing resistance, water relations and gas exchange characteristics. Results from 45 herbaceous and 42 woody species along elevational gradients in the Venezuelan high Andes were analysed.

Results: Leaf supercooling is the common avoidance response of woody plants to night-time freezing temperatures, while herbaceous plants tolerate frost. Trees and caulescent rosettes maintain more positive leaf water potentials under water deficit conditions compared to more tolerant herbaceous species. All plant growth-forms showed strong stomatal control under dry-season conditions.

Conclusions: Páramo plant growth-forms may be separated according to an avoidance-tolerance gradient in response to water deficit and low temperature resistance. Woody growth-forms tend to avoid both freezing and water stress, while herbaceous forms tolerate frost and resist an unfavourable water status. Grasses and cushion plants are at the tolerant extreme of the gradient and coincide in that both reach the highest elevations in the páramo. Andean giant rosettes are freezing avoidant, particularly susceptible to water deficit and the most vulnerable, of all growth-forms, to changing environmental conditions.     

Histophotometric study of alkaline phosphatase in ossification and liver of protein deficient mice

Summary Histochemical study of alkaline phosphatase in enchondral ossification of protein deficient mice showed an enzymatic reduction in areas where normally bone formation takes place. Liver parenchyme on the contrary shows an enzymatic increase in experimental animals. These results were confirmed with a histophotometric evaluation.