Control of immunity and allergy by steroid hormones

Steroid hormones, especially glucocorticoids, androgens, and estrogens, have profound influence on immunity. Recent studies using cell-type specific steroid hormone receptor-deficient mice have revealed the precise roles of some of these hormones in the immune system. Glucocorticoids are known to have strong anti-inflammatory and immunosuppressive effects and pleiotropic effects on innate and adaptive immune responses. They suppress the production of inflammatory cytokines by macrophages and DCs and the production of IFN-γ by NK cells, thus inhibiting innate immunity. By contrast, glucocorticoids enhance the immune response by inducing the expression of IL-7R and CXCR4 in T cells and the accumulation of T cells in lymphoid organs in accordance with the diurnal change of the glucocorticoid concentration. Thus, glucocorticoids suppress innate immunity but enhance adaptive immunity. Androgens suppress the homeostasis and activation of ILC2s and the differentiation of Th2 and Th17 cells and enhance the suppressive function of Tregs, thereby alleviating allergic airway inflammation. Thus, these steroid hormones have pleiotropic functions in the immune system. Further investigations are awaited on the regulation of immunity and allergy by estrogens using cell-specific steroid hormone receptor-deficient mice

Preparation of Au-Pd Core-shell Nanoparticles Supported TiO2 and Influence of Photocatalytic Activity on the Shell Thickness

ナノダイナミクス国際シンポジウム 平成22年1月21日(木) 於長崎大学Nagasaki Symposium on Nano-Dynamics 2010 (NSND2010), January 21, 2010, Nagasaki University, Nagasaki, Japan, Invited Lectur

Courtship Initiation Is Stimulated by Acoustic Signals in Drosophila melanogaster

Finding a mating partner is a critical task for many organisms. It is in the interest of males to employ multiple sensory modalities to search for females. In Drosophila melanogaster, vision is thought to be the most important courtship stimulating cue at long distance, while chemosensory cues are used at relatively short distance. In this report, we show that when visual cues are not available, sounds produced by the female allow the male to detect her presence in a large arena. When the target female was artificially immobilized, the male spent a prolonged time searching before starting courtship. This delay in courtship initiation was completely rescued by playing either white noise or recorded fly movement sounds to the male, indicating that the acoustic and/or seismic stimulus produced by movement stimulates courtship initiation, most likely by increasing the general arousal state of the male. Mutant males expressing tetanus toxin (TNT) under the control of Gr68a-GAL4 had a defect in finding active females and a delay in courtship initiation in a large arena, but not in a small arena. Gr68a-GAL4 was found to be expressed pleiotropically not only in putative gustatory pheromone receptor neurons but also in mechanosensory neurons, suggesting that Gr68a-positive mechanosensory neurons, not gustatory neurons, provide motion detection necessary for courtship initiation. TNT/Gr68a males were capable of discriminating the copulation status and age of target females in courtship conditioning, indicating that female discrimination and formation of olfactory courtship memory are independent of the Gr68a-expressing neurons that subserve gustation and mechanosensation. This study suggests for the first time that mechanical signals generated by a female fly have a prominent effect on males' courtship in the dark and leads the way to studying how multimodal sensory information and arousal are integrated in behavioral decision making

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Song choice is modulated by female movement in Drosophila males.

Mate selection is critical to ensuring the survival of a species. In the fruit fly, Drosophila melanogaster, genetic and anatomical studies have focused on mate recognition and courtship initiation for decades. This model system has proven to be highly amenable for the study of neural systems controlling the decision making process. However, much less is known about how courtship quality is regulated in a temporally dynamic manner in males and how a female assesses male performance as she makes her decision of whether to accept copulation. Here, we report that the courting male dynamically adjusts the relative proportions of the song components, pulse song or sine song, by assessing female locomotion. Male flies deficient for olfaction failed to perform the locomotion-dependent song modulation, indicating that olfactory cues provide essential information regarding proximity to the target female. Olfactory mutant males also showed lower copulation success when paired with wild-type females, suggesting that the male's ability to temporally control song significantly affects female mating receptivity. These results depict the consecutive inter-sex behavioral decisions, in which a male smells the close proximity of a female as an indication of her increased receptivity and accordingly coordinates his song choice, which then enhances the probability of his successful copulation

Trainer type-specific courtship conditioning of <i>TNT/Gr68a</i> males.

<p>Males received 60 min training by exposure to; an immature virgin female (iV), iV and mature virgin (mV) pheromone extract over mesh barrier, mV extract alone or a decapitated mV (mVd), then transferred to a clean chamber and tested with mVd. CI of the tester female was standardized by mean CI of sham to calculate a memory index (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003246#s4" target="_blank">Materials and Methods</a>). All experiments took place in dim red light. Each genotype is compared to own control. * (for wild type) and + (for <i>TNT/Gr68a</i>) indicate statistically significant differences (<i>P</i><0.05). Behavior was recorded in a round 8 mm diameter ×3 mm depth chamber.</p

Courtship is stimulated by the active movement of the target female.

<p>Wild-type males were paired with the indicated type of female. (A) Courtship initiation was assayed for wild-type, paired with a wingless (“mute”) or a decapitated (“silent”) wild-type female (upper panel) or a “silent” female and additional putative stimulatory cues (lower panel). (B) Mean values of courtship latency in each courtship condition. Mechanosensory stimulus, not excess amounts of female deposits, stimulates courtship initiation. Statistical significance is represented for comparison to the data indicated by each arrow (*<i>P</i><0.05). Behavior was recorded in a rectangular chamber with dimensions 70 mm×10 mm×7 mm.</p

Expression pattern of <i>Gr68a-GAL4</i>.

<p>(A) External appearance of the GFP expression on a head. Arrows and arrowheads indicate antennal third segment and maxillary palps respectively. (A′) Close-up of the second segment of the antenna. (B) Male forelegs. (C) Female foreleg. (D) Close-up of a male midleg. A cell body (arrowhead) is marked by GFP at base of mechanosensory bristle (arrow). (E) Root of male clasper teeth on the genitalia (arrow) and (F) male anal plate (arrow). (G) Tip of proboscis. (H) Root (arrowhead) of chemosensory bristles (arrow) of the wing margin. (I) Ventral view of female abdomen. (J) Frontal view of a dissected brain, showing antennal lobe (AL), suboesophageal ganglion (SOG), antennal mechanosensory and motor center (AMMC) and optic lobe (OL).</p

Courtship initiation and copulation success of the <i>TNT/Gr68a</i> male in large arena with or without visual cues.

<p>(A) Percentage of males that performed the first display of courtship orientation (left) and succeeded mating (right) in either white light (upper panel) or dim red light (lower panel) at each time point during 30 min observation period. (B) Mean values of courtship latency and copulation latency. Statistical significance is represented by capital letters for latencies under white light and small letters for dim-red light above each bar (<i>P</i><0.05). Behavior was recorded in a rectangular chamber with dimensions 70 mm×10 mm×7 mm.</p