Mouse to human comparative genetics reveals a novel immunoglobulin E-controlling locus on Hsa8q12

Atopy is a predisposition to hyperproduction of immunoglobulin E (IgE) against common environmental allergens. It is often associated with development of allergic diseases such as asthma, rhinitis, and dermatitis. Production of IgE is influenced by genetic and environmental factors. In spite of progress in the study of heredity of atopy, the genetic mechanisms of IgE regulation have not yet been completely elucidated. The analysis of complex traits can benefit considerably from integration of human and mouse genetics. Previously, we mapped a mouse IgE-controlling locus Lmr9 on chromosome 4 to a segment of <9 Mb. In this study, we tested levels of total IgE and 25 specific IgEs against inhalant and food allergens in 67 Czech atopic families. In the position homologous to Lmr9 on chromosome 8q12 marked by D8S285, we demonstrated a novel human IgE-controlling locus exhibiting suggestive linkage to composite inhalant allergic sensitization (limit of detection, LOD = 2.11, P = 0.0009) and to nine specific IgEs, with maximum LOD (LOD = 2.42, P = 0.0004) to plantain. We also tested 16 markers at previously reported chromosomal regions of atopy. Linkage to plant allergens exceeding the LOD > 2.0 was detected at 5q33 (D5S1507, LOD = 2.11, P = 0.0009) and 13q14 (D13S165, LOD = 2.74, P = 0.0002). The significant association with plant allergens (quantitative and discrete traits) was found at 7p14 (D7S2250, corrected P = 0.026) and 12q13 (D12S1298, corrected P = 0.043). Thus, the finding of linkage on chromosome 8q12 shows precision and predictive power of mouse models in the investigation of complex traits in humans. Our results also confirm the role of loci at 5q33, 7p14, 12q14, and 13q13 in control of IgE. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Reproductive biology of female blue shark <Emphasis Type="Italic">Prionace glauca</Emphasis> in the southeastern Pacific Ocean

Polyandry is extremely common across a wide range of organisms. In promiscuous mating systems, females are often sexually harassed by males, but at the same time obtain benefits from multiple mating. It remains unclear whether polyandry is exclusively imposed by males or is also promoted by females. Here, we investigated this question by recording the time spent by female guppies near a single male or a group of males with similar size and colour patterns over three consecutive days. We accounted for the effect of shoaling by using a control treatment where a group of females was used instead of a group of males. Results showed that females spent significantly more time near the group of males, but not with the group of females. In the presence of a group of males, total female mating preference time did not change over the course of the study, but rather shifted from spending more time near the single male at the beginning of the experiment to spending more time near the group of males. The consequence of this female preference for associating with a group of males in a non-experimental setup would be to promote multiple mating. Our result indicates that polyandry in guppies is at least partially encouraged by females, and not entirely a consequence of male sexual behaviour.     

Modification of the enantioselectivity of two homologous thermophilic carboxylesterases from<Emphasis Type="Italic"> Alicyclobacillus acidocaldarius</Emphasis> and<Emphasis Type="Italic"> Archaeoglobus fulgidus</Emphasis> by random mutagenesis and screening

The esterase genes est2 from Alicyclobacillus acidocaldarius and AF1716 from Archaeoglobus fulgidus were subjected to error-prone PCR in an effort to increase the low enantioselectivity of the corresponding enzymes EST2 and AFEST, respectively. The model substrate ( RS)- p-nitrophenyl-2-chloropropionate was chosen to produce ( S)-2-chloropropionic acid, an important intermediate in the synthesis of some optically pure compounds, such as the herbicide mecoprop. In the case of EST2, a single mutant, Leu212Pro, was obtained showing a slightly enhanced preference toward the ( S) substrate; in the case of AFEST, a double mutant, Leu101Ile/Asp117Gly, was obtained showing an increased preference in the opposite direction. The 3-D structures of the EST2 and AFEST enzymes were analyzed by molecular modeling to determine the effects of the mutations. Mutations were positioned differently in the structures, but in both cases caused small modifications around the active site and in the oxyanion loop.     

Restaurant and food service life cycle assessment and development of a sustainability standard

Purpose  

There is no clear guidance for responsible food service operations to reduce their environmental footprint, so the efforts put forth by a restaurant may not have the environmental impact intended. As a result, Green Seal conducted life cycle assessment research on restaurants and food service operations to define priorities for environmental improvement. This information was then used to develop a sustainability standard and certification (i.e., ecolabel) program.     

昆虫嗅觉可塑性研究进展

嗅觉是昆虫的主要感觉模式,在昆虫的重要行为活动如寻找配偶、定位寄主、选择产卵场所等中起着关键作用。昆虫通过触角等外周嗅觉器官感受外界的化学信号并转化为电信号,电信号传输到中枢神经系统进行加工整合,最后通过大脑发出指令调控自身关键的行为。昆虫需要在合适的时机对不同气味作出反应,从而保证其能够在不同生理状态下完成特定的行为。这就要求昆虫的嗅觉系统具有可塑性,即根据不同的生理状态,如日龄、取食状态、交配、节律等对相同气味作出不同的反应。本文综述了不同生理状态对昆虫嗅觉行为和嗅觉神经系统的影响,以及昆虫嗅觉可塑性产生的机制,为加深和扩展人们对昆虫嗅觉系统的认识和建立新的害虫防控策略提供参考。     

Effects of culture conditions on osteogenic differentiation in human mesenchymal stem cells

Human bone marrow-derived mesenchymal stem cells (hBMMSCs) must differentiate into osteogenic cells to allow for successful bone regeneration. In this study, we investigated the effects of different combinations of three soluble osteogenic differentiation-inducing factors [L-ascorbic acid (AC), beta-glycerophosphate (betaG), and bone morphogenic protein-2 (BMP-2)] and the presence of a hydroxyapatite (HA) substrate on hBMMSC osteogenic differentiation in vitro. hBMMSCs were cultured in medium containing various combinations of the soluble factors on culture plates with or without HA coating. After 7 days of culture, alkaline phosphatase (ALP) activity, calcium deposition, and osteoprotegerin (OPG) and osteopontin (OPN) expression were measured. The effects of individual and combined factors were evaluated using a factorial analysis method. BMP-2 predominantly affected expression of early markers of osteogenic differentiation (ALP and OPG). HA had the highest positive effect on OPN expression and calcium deposition. The interaction between AC, betaG, and HA had the second highest positive effect on ALP activity.     

Characterization of aerobic heterotrophic bacteria in cold and nutrient-poor freshwater ecosystems

Aerobic heterotrophic bacteria present in the surface water of three cold and nutrient-poor lakes in the Chilean Patagonia (Alto Reino, Las Dos Torres and Venus) were analysed for genetic similarity and metabolic diversity using 16S ribosomal DNA and the Biolog EcoPlate^TM system, respectively. Bacterial fingerprints of water samples in enriched and non-enriched nutrient broth demonstrated a >50% fingerprinting similarity between the lakes. Metabolic activity was also similar. However, the Biolog EcoPlate^TM system carbon substrates revealed functional diversity. Lake Las Dos Torres showed the most fingerprinting similarity between enriched and non-enriched cold water samples. The amounts of living and viable bacteria were also higher in this lake’s water sample, suggesting a predominance of facultative oligotrophic groups. DNA sequencing analysis demonstrated the presence of phylum Bacteroidetes in Lake Alto Reino; phyla Bacteroidetes and Gammaproteobacteria in Lake Las Dos Torres; and phyla Bacteroidetes, Alphaproteobacteria, and Gammaproteobacteria in Lake Venus. Although each lake had a unique bacterial community structure, the different bacterial groups may be performing similar metabolic functions, given the similarity in extreme environmental conditions.     

HIV-1 TAT-mediated protein transduction and subcellular localization using novel expression vectors

Several novel prokaryotic and eukaryotic expression vectors were constructed for protein transduction and subcellular localization. These vectors employed an N-terminal stretch of 11 basic amino acid residues (47-57) from the human immunodeficiency virus type 1 (HIV-1) TAT protein transduction domain (PTD) for protein translocation and cellular localization. The vectors also contained a six-histidine (His(6)) tag at the N- or C-terminus for convenient purification and detection, and a multiple cloning site for easy insertion of foreign genes. Some heterologous genes including HSV-TK, Bcl-rambo, Smac/DIABLO and GFP were fused in-frame to TAT PTD and successfully overexpressed in Escherichia coli. The purified TAT-GFP fusion protein was able to transduce into the mammalian cells and was found to locate mainly in the cytosol when exogenously added to the cell culture medium. However, using a transfection system, mammalian-expressed TAT-GFP predominantly displayed a nuclear localization and nucleolar accumulation in mammalian cell lines. This discrepancy implies that the exact subcellular localization of transduced protein may depend on cell type, the nature of imported proteins and delivery approach. Taken together, our results demonstrate that a TAT PTD length of 11 amino acids was sufficient to confer protein internalization and its subsequent cellular localization. These novel properties allow these vectors to be useful for studying protein transduction and nuclear import.