Five nicotinic acetylcholine receptor subunits from the Morotoge shrimp, <i>Pandalopsis japonica</i>: cloning, tissue distribution, and functional expression in <i>Xenopus</i> oocytes

<div><p>The nicotinic acetylcholine receptor (nAChR) is a member of the ligand-gated ion channel (LGIC) family and is composed of five subunits arranged around a central pore. Expressed sequence tag screening and traditional cloning strategies revealed five full-length cDNAs encoding nAChR subunit homologs (Pajα3, Pajα10, Pajα11, Pajα12, and Pajβ1) in the Morotoge shrimp, <i>Pandalopsis japonica</i>. The nAChR subunits exhibited common structural characteristics, including a signal peptide sequence, a large N-terminal extracellular domain with conserved motifs for ligand binding (loops A–F), and a transmembrane (TM) domain with four hydrophobic TM motifs (TM1–TM4). Based on the conserved GEK motifs located just before TM2, all five nAChR subunits from <i>P. japonica</i> appear to be cation-selective ion channels. Among the five subunits, Pajα3 and Pajβ1 clustered together with insect core groups, whereas Pajα10, Pajα11, and Pajα12 were classified as a divergent group. Three distinct transcripts were identified in Pajα3, presumably due to alternative splicing between TM3 and TM4, which may be involved in channel formation with other subunits. All five nAChR subunits were expressed predominantly in neuronal tissues, including the brain, sinus gland/X-organ complex, thoracic ganglia, and abdominal ganglia, with no significant differences in subunit expression levels among the neuronal tissues. The five shrimp nAChR subunits could not be functionally expressed in <i>Xenopus</i> oocytes, but coexpression of Pajβ1 and rat α4 subunit (Rα4) formed functional channels responding to acetylcholine. Functional expression of vertebrate α subunit (Rα4) with invertebrate β1 subunit (Pajβ1) will expand our knowledge regarding the structural characteristics and molecular gating mechanism of invertebrate nAChRs.</p></div

Mating Behavior of <i>Daphnia</i>: Impacts of Predation Risk, Food Quantity, and Reproductive Phase of Females

<div><p>High predation risk and food depletion lead to sexual reproduction in cyclically parthenogenetic <i>Daphnia</i>. Mating, the core of sexual reproduction, also occurs under these conditions. Assessment of the environmental conditions and alteration of mating efforts may aid in determining the success of sexual reproduction. Here, we evaluated the impacts of predation risk, food quantity, and reproductive phase of females on the mating behavior of <i>Daphnia obtusa</i> males including contact frequency and duration using video analysis. Mating–related behavior involved male–female contact (mating) as well as male–male contact (fighting). Mating frequency increased while unnecessary fighting decreased in the presence of predation risk. In addition, low food concentration reduced fighting between males. Males attempted to attach to sexual females more than asexual females, and fighting occurred more frequently in the presence of sexual females. Duration of mating was relatively long; however, males separated shortly after contact in terms of fighting behavior. Thus, assessment of environmental factors and primary sexing of mates were performed before actual contact, possibly mechanically, and precise sex discrimination was conducted after contact. These results suggest that mating in <i>Daphnia</i> is not a random process but rather a balance between predation risk and energetic cost that results in changes in mating and fighting strategies.</p></div

Example of video analysis of the mating process in <i>Daphnia obtusa</i>.

<p>Frame numbers of the video from encounter to separation of each contact were converted into time to determine the duration of the contact (black line: trajectory of male; grey line: trajectory of female; dashed line: trajectory of male and female during mating).</p

Insemination behaviors of the <i>Daphnia obtusa</i> male during contact with asexual female of <i>D. obtusa</i> (A) or <i>D. galeata</i> (B).

<p>Insemination behaviors of the <i>Daphnia obtusa</i> male during contact with asexual female of <i>D. obtusa</i> (A) or <i>D. galeata</i> (B).</p

Contact frequencies and duration times of mating and fighting of <i>Daphnia obtusa</i> according to food quantity.

<p>Observation was performed for 10 minutes. Each column represents the mean ± SE of 48 replicates.</p

Contact frequencies and duration times of mating and fighting of <i>Daphnia obtusa</i> according to reproductive phase of females.

<p>Observation was performed for 10 minutes. Each column represents the mean ± SE of 48 replicates.</p

Contact frequencies and duration times of mating and fighting of <i>Daphnia obtusa</i> according to the absence or presence of fish kairomones.

<p>Observation was performed for 10 minutes. Each column represents the mean ± SE of 48 replicates.</p

Additional file 1 of Exploring the Smoking-Epilepsy Nexus: a systematic review and meta-analysis of observational studies

Additional file 1

Exploring a New Biocatalyst from <i>Bacillus thuringiensis</i> JNU01 for Polyethylene Biodegradation

The decomposition of polyethylene (PE), an extremely recalcitrant synthetic polymer, using microorganisms is an ideal and sustainable method for future PE biotreatment. We isolated a set of PE-biodegrading Bacillus species from a landfill site. Among them, Bacillus thuringiensis JNU01 exhibited the highest cell growth rate in PE media, which means it effectively decomposed PE to use in the metabolic pathway as a sole carbon source. B. thuringiensis JNU01-treated PE showed new chemical functional groups such as hydroxyl, carboxyl, and amide groups in the inert hydrocarbon. Scanning electron microscopy revealed considerable physical damage on the surface of the PE film after treatment with B. thuringiensis JNU01. Furthermore, various alkane derivatives obtained from PE were characterized using gas chromatography–mass spectrometry. On the contrary, an increase in the mRNA transcriptional levels of B. thuringiensis JNU01 in the presence of PE suggests that a CYP102A5 variant (CYP102A5.v1) is involved in PE biodegradation. Finally, we confirmed that purified CYP102A5.v1 catalyzes the hydroxylation of PE by a NADPH oxidation assay and Fourier transform infrared analysis. These results show that B. thuringiensis JNU01 is a potential PE decomposer and suggest that CYP102A5.v1 can be a trigger biocatalyst for hydroxylation of PE

Image2_YH29407 with anti-PD-1 ameliorates anti-tumor effects via increased T cell functionality and antigen presenting machinery in the tumor microenvironment.JPEG

Among cancer cells, indoleamine 2, 3-dioxygenase1 (IDO1) activity has been implicated in improving the proliferation and growth of cancer cells and suppressing immune cell activity. IDO1 is also responsible for the catabolism of tryptophan to kynurenine. Depletion of tryptophan and an increase in kynurenine exert important immunosuppressive functions by activating regulatory T cells and suppressing CD8+ T and natural killer (NK) cells. In this study, we compared the anti-tumor effects of YH29407, the best-in-class IDO1 inhibitor with improved pharmacodynamics and pharmacokinetics, with first and second-generation IDO1 inhibitors (epacadostat and BMS-986205, respectively). YH29407 treatment alone and anti-PD-1 (aPD-1) combination treatment induced significant tumor suppression compared with competing drugs. In particular, combination treatment showed the best anti-tumor effects, with most tumors reduced and complete responses. Our observations suggest that improved anti-tumor effects were caused by an increase in T cell infiltration and activity after YH29407 treatment. Notably, an immune depletion assay confirmed that YH29407 is closely related to CD8+ T cells. RNA-seq results showed that treatment with YH29407 increased the expression of genes involved in T cell function and antigen presentation in tumors expressing ZAP70, LCK, NFATC2, B2M, and MYD88 genes. Our results suggest that an IDO1 inhibitor, YH29407, has enhanced PK/PD compared to previous IDO1 inhibitors by causing a change in the population of CD8+ T cells including infiltrating T cells into the tumor. Ultimately, YH29407 overcame the limitations of the competing drugs and displayed potential as an immunotherapy strategy in combination with aPD-1.</p