Analysis of the activity rhythm of the predatory bug Orius sauteri (Poppius) (Heteroptera: Anthocoridae) for optimizing its selective light attraction

Applied Entomology and Zoology - The minute pirate bug Orius sauteri (Poppius) (Heteroptera: Anthocoridae) is a major natural enemy of micro-pests and is expected to be an effective pest-control...     

Base composition and nucleosome density in exonic and intronic regions in genes of the filamentous ascomycetes Aspergillus nidulans and Aspergillus oryzae

We sequenced nucleosomal DNA fragments of the filamentous ascomycetes Aspergillus nidulans and Aspergillus oryzae and then mapped those sequences on their genomes. We compared the GC content and nucleosome density in the exonic and intronic regions in the genes of A. nidulans and A. oryzae. Although the GC content and nucleosome density in the exonic regions tended to be higher than those in the intronic regions, the difference in the distribution of the GC content was more notable than that of the nucleosome density. Next, we compared the GC content and nucleosome density in the exonic regions of 9616 orthologous gene pairs. In both Aspergillus species, the GC content did not correlate with the nucleosome density. In addition, the Spearman's rank correlation coefficient (ρ = 0.51) between the GC content of the exonic regions of the 9616 orthologous gene pairs was higher than that (ρ = 0.31) of the nucleosome densities of A. nidulans and A. oryzae. These results strongly suggest that the GC content in the exons of the orthologous gene pairs has been conserved during evolution but the nucleosome density has varied throughout.     

The SNP in the promoter region of the bovine ELOVL5 gene influences economic traits including subcutaneous fat thickness

Genetic analyses have contributed to improvements of economically important traits derived from adipose tissue such as fatty acid composition in beef. Elongation of very long chain fatty acids (ELOVL) genes encode for the enzymes that play an important role in elongation of long-chain fatty acids. In this study, we aimed to discover genetic polymorphisms of ELOVL gene family in cattle populations to develop genetic markers. As a result, five synonymous mutations were detected in the coding regions of the ELOVL1, ELOVL2, ELOVL3 and ELOVL5 genes. In addition, six mutations were identified in promoter region of the ELOVL5. Two of five mutations in the promoter region of ELOVL5 were expected to alter the ELOVL5 expression and influence the economic traits, because of the high synteny of the region which was essential for activation of Elovl5 in mouse. Therefore, we performed association analysis between the genotypes and traits and our result revealed that T allele of g.-110T>C in ELOVL5 gene promoter indicated significantly thinner subcutaneous fat thickness (TT, 2.39 cm; CT, 2.35 cm) than that of C allele (CC, 2.68 cm) in a Japanese Black population. Our results suggest that the g.-110T>C is a useful genetic marker for the breeding in beef cattle.     

Anti‐adhesive property of P‐selectin glycoprotein ligand‐1 (PSGL‐1) due to steric hindrance effect

P‐selectin glycoprotein ligand‐1 (PSGL‐1) is an adhesive molecule that is known to be a ligand for P‐selectin. An anti‐adhesive property of PSGL‐1 has not been previously reported. In this study, we show that PSGL‐1 expression is anti‐adhesive for adherent cells and we have elucidated the underlying mechanism. Overexpression of PSGL‐1 induced cell rounding and floating in HEK293T cells. Similar phenomena were demonstrated in other adherent cell lines with overexpression of PSGL‐1. PSGL‐1 overexpression inhibits access of antibodies to cell surface molecules such as integrins, HLA and CD25. Cells transfected with PSGL‐1 deletion mutants that lack a large part of the extracellular domain and chimeric construct expressing extracellular CD86 and intracellular PSGL‐1 only showed rounded morphology, but there are no floating cells. These results indicated that PSGL‐1 causes steric hindrance due to the extended structure of its extracellular domain that is highly O‐glycosylated, but intracellular domain also has some effect on cell rounding. This study implies that PSGL‐1 has Janus‐faced functions, being both adhesive and anti‐adhesive. J. Cell. Biochem. 114: 1271–1285, 2013. © 2013 Wiley Periodicals, Inc.     

Focus Issue on Calcium Signaling: Analyses of a Gravistimulation-Specific Ca2+ Signature in Arabidopsis using Parabolic Flights

Gravity is a critical environmental factor affecting the morphology and functions of organisms on the Earth. Plants sense changes in the gravity vector (gravistimulation) and regulate their growth direction accordingly. In Arabidopsis (Arabidopsis thaliana) seedlings, gravistimulation, achieved by rotating the specimens under the ambient 1g of the Earth, is known to induce a biphasic (transient and sustained) increase in cytoplasmic calcium concentration ([Ca2+]_c). However, the [Ca2+]_c increase genuinely caused by gravistimulation has not been identified because gravistimulation is generally accompanied by rotation of specimens on the ground (1g), adding an additional mechanical signal to the treatment. Here, we demonstrate a gravistimulation-specific Ca²⁺ response in Arabidopsis seedlings by separating rotation from gravistimulation by using the microgravity (less than 10⁻⁴g) conditions provided by parabolic flights. Gravistimulation without rotating the specimen caused a sustained [Ca2+]_c increase, which corresponds closely to the second sustained [Ca2+]_c increase observed in ground experiments. The [Ca2+]_c increases were analyzed under a variety of gravity intensities (e.g. 0.5g, 1.5g, or 2g) combined with rapid switching between hypergravity and microgravity, demonstrating that Arabidopsis seedlings possess a very rapid gravity-sensing mechanism linearly transducing a wide range of gravitational changes (0.5g–2g) into Ca²⁺ signals on a subsecond time scale.Calcium ion (Ca²⁺) functions as an intracellular second messenger in many signaling pathways in plants (White and Broadley, 2003; Hetherington and Brownlee, 2004; McAinsh and Pittman, 2009; Spalding and Harper, 2011). Endogenous and exogenous signals are spatiotemporally encoded by changing the free cytoplasmic concentration of Ca²⁺ ([Ca2+]_c), which in turn triggers [Ca2+]_c-dependent downstream signaling (Sanders et al., 2002; Dodd et al., 2010). A variety of [Ca2+]_c increases induced by diverse environmental and developmental stimuli are reported, such as phytohormones (Allen et al., 2000), temperature (Plieth et al., 1999; Dodd et al., 2006), and touch (Knight et al., 1991; Monshausen et al., 2009). The [Ca2+]_c increase couples each stimulus and appropriate physiological responses. In the Ca²⁺ signaling pathways, the stimulus-specific [Ca2+]_c pattern (e.g. amplitude and oscillation) provide the critical information for cellular signaling (Scrase-Field and Knight, 2003; Dodd et al., 2010). Therefore, identification of the stimulus-specific [Ca2+]_c signature is crucial for an understanding of the intracellular signaling pathways and physiological responses triggered by each stimulus, as shown in the case of cold acclimation (Knight et al., 1996; Knight and Knight, 2000).Plants often exhibit biphasic [Ca2+]_c increases in response to environmental stimuli. Thus, slow cooling causes a fast [Ca2+]_c transient followed by a second, extended [Ca2+]_c increase in Arabidopsis (Arabidopsis thaliana; Plieth et al., 1999; Knight and Knight, 2000). The Ca²⁺ channel blocker lanthanum (La³⁺) attenuated the fast transient but not the following increase (Knight and Knight, 2000), suggesting that these two [Ca2+]_c peaks have different origins. Similarly, hypoosmotic shock caused a biphasic [Ca2+]_c increase in tobacco (Nicotiana tabacum) suspension-culture cells (Takahashi et al., 1997; Cessna et al., 1998). The first [Ca2+]_c peak was inhibited by gadolinium (Gd³⁺), La³⁺, and the Ca²⁺ chelator EGTA (Takahashi et al., 1997; Cessna et al., 1998), whereas the second [Ca2+]_c increase was inhibited by the intracellular Ca²⁺ store-depleting agent caffeine but not by EGTA (Cessna et al., 1998). The amplitude of the first [Ca2+]_c peak affected the amplitude of the second increase and vice versa (Cessna et al., 1998). These results suggest that even though the two [Ca2+]_c peaks originate from different Ca²⁺ fluxes (e.g. Ca²⁺ influx through the plasma membrane and Ca²⁺ release from subcellular stores, respectively), they are closely interrelated, showing the importance of the kinetic and pharmacological analyses of these [Ca2+]_c increases.Changes in the gravity vector (gravistimulation) could work as crucial environmental stimuli in plants and are generally achieved by rotating the specimens (e.g. +180°) in ground experiments. Use of Arabidopsis seedlings expressing apoaequorin, a Ca²⁺-reporting photoprotein (Plieth and Trewavas, 2002; Toyota et al., 2008a), has revealed that gravistimulation induces a biphasic [Ca2+]_c increase that may be involved in the sensory pathway for gravity perception/response (Pickard, 2007; Toyota and Gilroy, 2013) and the intracellular distribution of auxin transporters (Benjamins et al., 2003; Zhang et al., 2011). These two Ca²⁺ changes have different characteristics. The first transient [Ca2+]_c increase depends on the rotational velocity but not angle, whereas the second sustained [Ca2+]_c increase depends on the rotational angle but not velocity. The first [Ca2+]_c transient was inhibited by Gd³⁺, La³⁺, and the Ca²⁺ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid but not by ruthenium red (RR), whereas the second sustained [Ca2+]_c increase was inhibited by all these chemicals. These results suggest that the first transient and second sustained [Ca2+]_c increases are related to the rotational stimulation and the gravistimulation, respectively, and are mediated by distinct molecular mechanisms (Toyota et al., 2008a). However, it has not been demonstrated directly that the second sustained [Ca2+]_c increase is induced solely by gravistimulation; it could be influenced by other factors, such as an interaction with the first transient [Ca2+]_c increase (Cessna et al., 1998), vibration, and/or deformation of plants during the rotation.To elucidate the genuine Ca²⁺ signature in response to gravistimulation in plants, we separated rotation and gravistimulation under microgravity (μg; less than 10⁻⁴g) conditions provided by parabolic flight (PF). Using this approach, we were able to apply rotation and gravistimulation to plants separately (Fig. 1). When Arabidopsis seedlings were rotated +180° under μg conditions, the [Ca2+]_c response to the rotation was transient and almost totally attenuated in a few seconds. Gravistimulation (transition from μg to 1.5g) was then applied to these prerotated specimens at the terminating phase of the PF. This gravistimulation without simultaneous rotation induced a sustained [Ca2+]_c increase. The kinetic properties of this sustained [Ca2+]_c increase were examined under different gravity intensities (0.5g–2g) and sequences of gravity intensity changes (Fig. 2A). This analysis revealed that gravistimulation-specific Ca²⁺ response has an almost linear dependency on gravitational acceleration (0.5g–2g) and an extremely rapid responsiveness of less than 1 s.Open in a separate windowFigure 1.Diagram of the experimental procedures for applying separately rotation and gravistimulation to Arabidopsis seedlings. Rotatory stimulation (green arrow) was applied by rotating the seedlings 180° under μg conditions, and 1.5g 180° rotation gravistimulation (blue arrow) was applied to the prerotated seedlings after μg.Open in a separate windowFigure 2.Acceleration, temperature, humidity, and pressure in an aircraft during flight experiments. A, Accelerations along x, y, and z axes in the aircraft during PF. The direction of flight (FWD) and coordinates (x, y, and z) are indicated in the bottom graph. The inset shows an enlargement of the acceleration along the z axis (gravitational acceleration) during μg conditions lasting for approximately 20 s. B, Temperature, humidity, and pressure in the aircraft during PF. Shaded areas in graphs denote the μg condition.     

Facilitated Hyperpolarization Signaling in Vascular Smooth Muscle-overexpressing TRIC-A Channels

The TRIC channel subtypes, namely TRIC-A and TRIC-B, are intracellular monovalent cation-specific channels and likely mediate counterion movements to support efficient Ca²⁺ release from the sarco/endoplasmic reticulum. Vascular smooth muscle cells (VSMCs) contain both TRIC subtypes and two Ca²⁺ release mechanisms; incidental opening of ryanodine receptors (RyRs) generates local Ca²⁺ sparks to induce hyperpolarization and relaxation, whereas agonist-induced activation of inositol trisphosphate receptors produces global Ca²⁺ transients causing contraction. Tric-a knock-out mice develop hypertension due to insufficient RyR-mediated Ca²⁺ sparks in VSMCs. Here we describe transgenic mice overexpressing TRIC-A channels under the control of a smooth muscle cell-specific promoter. The transgenic mice developed congenital hypotension. In Tric-a-overexpressing VSMCs from the transgenic mice, the resting membrane potential decreased because RyR-mediated Ca²⁺ sparks were facilitated and cell surface Ca²⁺-dependent K⁺ channels were hyperactivated. Under such hyperpolarized conditions, L-type Ca²⁺ channels were inactivated, and thus, the resting intracellular Ca²⁺ levels were reduced in Tric-a-overexpressing VSMCs. Moreover, Tric-a overexpression impaired inositol trisphosphate-sensitive stores to diminish agonist-induced Ca²⁺ signaling in VSMCs. These altered features likely reduced vascular tonus leading to the hypotensive phenotype. Our Tric-a-transgenic mice together with Tric-a knock-out mice indicate that TRIC-A channel density in VSMCs is responsible for controlling basal blood pressure at the whole-animal level.     

The Bcl-2 Homology Domain 3 (BH3)-only Proteins Bim and Bid Are Functionally Active and Restrained by Anti-apoptotic Bcl-2 Family Proteins in Healthy Liver

An intrinsic pathway of apoptosis is regulated by the B-cell lymphoma-2 (Bcl-2) family proteins. We previously reported that a fine rheostatic balance between the anti- and pro-apoptotic multidomain Bcl-2 family proteins controls hepatocyte apoptosis in the healthy liver. The Bcl-2 homology domain 3 (BH3)-only proteins set this rheostatic balance toward apoptosis upon activation in the diseased liver. However, their involvement in healthy Bcl-2 rheostasis remains unknown. In the present study, we focused on two BH3-only proteins, Bim and Bid, and we clarified the Bcl-2 network that governs hepatocyte life and death in the healthy liver. We generated hepatocyte-specific Bcl-xL- or Mcl-1-knock-out mice, with or without disrupting Bim and/or Bid, and we examined hepatocyte apoptosis under physiological conditions. We also examined the effect of both Bid and Bim disruption on the hepatocyte apoptosis caused by the inhibition of Bcl-xL and Mcl-1. Spontaneous hepatocyte apoptosis in Bcl-xL- or Mcl-1-knock-out mice was significantly ameliorated by Bim deletion. The disruption of both Bim and Bid completely prevented hepatocyte apoptosis in Bcl-xL-knock-out mice and weakened massive hepatocyte apoptosis via the additional in vivo knockdown of mcl-1 in these mice. Finally, the hepatocyte apoptosis caused by ABT-737, which is a Bcl-xL/Bcl-2/Bcl-w inhibitor, was completely prevented in Bim/Bid double knock-out mice. The BH3-only proteins Bim and Bid are functionally active but are restrained by the anti-apoptotic Bcl-2 family proteins under physiological conditions. Hepatocyte integrity is maintained by the dynamic and well orchestrated Bcl-2 network in the healthy liver.     

Interactions between climatic and production factors on returns of female pigs to service during summer in Japanese commercial breeding herds

The objectives of this study were to determine the associations between climatic factors and production factors for returns to service of female pigs during summer and to quantify the associations between these factors and occurrences of returns to service. The factors that were assessed were as follows: maximum temperature (HT), relative humidity, age of gilts at first mating, parity, weaning-to-first-mating interval (WMI), and lactation length. The study analyzed records of 18,307 gilts in 99 herds and 78,135 parity records of 56,322 sows in 103 herds; all the females were first-serviced between June and September, 2007 to 2009. Average daily HT and relative humidity for 15 days post-service of a female were obtained from 21 local weather stations and coordinated with the performance data of the respective local herds. The returns to service were categorized into three groups: regular returns (RRs: 18–24 days), irregular returns (IRs: 25–38 days), and late returns to service (LRs: 39 days or later). Two-level mixed-effects models were applied to the data by using a herd at level 2 and an individual record at level 1. In mated gilts, the occurrences (%) of RRs, IRs, and LRs were 4.8%, 1.8%, and 5.3%, respectively. In mated sows, the respective occurrences were 3.3%, 1.8%, and 4.2%. Mean values (ranges) of HT and relative humidity were 28.4 °C (13.6 °C–39.8 °C) and 73.4% (35.0%–98.0%), respectively. In gilts, as HT increased from 25 °C to 30 °C, the occurrence of RR increased from 3.7% to 4.4% (P < 0.05). However, there was no association between the occurrence of RR and either relative humidity (P = 0.17) or age at first mating (P = 0.23). In addition, there were no associations between the occurrences of either gilt IR or LR and HT (P ≥ 0.05), relative humidity (P ≥ 0.46), or age at first mating (P ≥ 0.32). In sows, greater occurrences of RRs, IRs, and LRs were associated with higher HT, lower parity, and a WMI of 7 days or longer (P < 0.05), but they were not associated with relative humidity (P ≥ 0.62) or lactation length (P ≥ 0.13). The occurrence of RRs in sows of all WMI groups increased 1.22 (1.04⁵) times for each 5 °C increase in HT. For sows with WMI 0 to 6 days, each 5 °C rise in HT increased the occurrence of IRs and LRs by 1.36 (1.06⁵) and 1.27 (1.05⁵) times, respectively. However, there was no association between increased HT and occurrences of IRs or LRs for sows with WMI 7 days or longer (P ≥ 0.38). Therefore, in order to prevent returns to service, it is recommended that producers apply cooling management for females during the post-service periods in summer.     

Electrophysiological Characterization of the Mechanosensitive Channel MscCG in Corynebacterium glutamicum

Corynebacterium glutamicum MscCG, also referred to as NCgl1221, exports glutamate when biotin is limited in the culture medium. MscCG is a homolog of Escherichia coli MscS, which serves as an osmotic safety valve in E. coli cells. Patch-clamp experiments using heterogeneously expressed MscCG have shown that MscCG is a mechanosensitive channel gated by membrane stretch. Although the association of glutamate secretion with the mechanosensitive gating has been suggested, the electrophysiological characteristics of MscCG have not been well established. In this study, we analyzed the mechanosensitive gating properties of MscCG by expressing it in E. coli spheroplasts. MscCG is permeable to glutamate, but is also permeable to chloride and potassium. The tension at the midpoint of activation is 6.68 ± 0.63 mN/m, which is close to that of MscS. The opening rates at saturating tensions and closing rates at zero tension were at least one order of magnitude slower than those observed for MscS. This slow kinetics produced strong opening-closing hysteresis in response to triangular pressure ramps. Whereas MscS is inactivated under sustained stimulus, MscCG does not undergo inactivation. These results suggest that the mechanosensitive gating properties of MscCG are not suitable for the response to abrupt and harmful changes, such as osmotic downshock, but are tuned to execute slower processes, such as glutamate export.