Genetic structure of Pacific crown-of-thorns starfish (Acanthaster cf. solaris) in southern Japan based on genome-wide RADseq analysis

Coral Reefs - Pacific crown-of-thorns starfish (Acanthaster cf. solaris) are known to be widely distributed, and previous studies (showing limited genetic structure) suggest that there are high...     

Integrative genomic phylogeography reveals signs of mitonuclear incompatibility in a natural hybrid goby population

Hybridization between divergent lineages generates new allelic combinations. One mechanism that can hinder the formation of hybrid populations is mitonuclear incompatibility, that is, dysfunctional interactions between proteins encoded in the nuclear and mitochondrial genomes (mitogenomes) of diverged lineages. Theoretically, selective pressure due to mitonuclear incompatibility can affect genotypes in a hybrid population in which nuclear genomes and mitogenomes from divergent lineages admix. To directly and thoroughly observe this key process, we de novo sequenced the 747‐Mb genome of the coastal goby, Chaenogobius annularis, and investigated its integrative genomic phylogeographics using RNA‐sequencing, RAD‐sequencing, genome resequencing, whole mitogenome sequencing, amplicon sequencing, and small RNA‐sequencing. Chaenogobius annularis populations have been geographically separated into Pacific Ocean (PO) and Sea of Japan (SJ) lineages by past isolation events around the Japanese archipelago. Despite the divergence history and potential mitonuclear incompatibility between these lineages, the mitogenomes of the PO and SJ lineages have coexisted for generations in a hybrid population on the Sanriku Coast. Our analyses revealed accumulation of nonsynonymous substitutions in the PO‐lineage mitogenomes, including two convergent substitutions, as well as signals of mitochondrial lineage‐specific selection on mitochondria‐related nuclear genes. Finally, our data implied that a microRNA gene was involved in resolving mitonuclear incompatibility. Our integrative genomic phylogeographic approach revealed that mitonuclear incompatibility can affect genome evolution in a natural hybrid population.     

Potent Anti-Candida Fraction Isolated from Capsicum chinense Fruits Contains an Antimicrobial Peptide That is Similar to Plant Defensin and is Able to Inhibit the Activity of Different α-Amylase Enzymes

Antimicrobial peptides (AMPs) are molecules present in several life forms, possess broad-spectrum of inhibitory activity against pathogenic microorganisms, and are a promising alternative to combat the multidrug resistant pathogens. The aim of this work was to identify and characterize AMPs from Capsicum chinense fruits and to evaluate their inhibitory activities against yeasts of the genus Candida and α-amylases. Initially, after protein extraction from fruits, the extract was submitted to anion exchange chromatography resulting two fractions. Fraction D1 was further fractionated by molecular exclusion chromatography, and three fractions were obtained. These fractions showed low molecular mass peptides, and in fraction F3, only two protein bands of approximately 6.5 kDa were observed. Through mass spectrometry, we identified that the lowest molecular mass protein band of fraction F3 showed similarity with AMPs from plant defensin family. We named this peptide CcDef3 (Capsicum chinense defensin 3). The antifungal activity of these fractions was analyzed against yeasts of the genus Candida. At 200 μg/mL, fraction F1 inhibited the growth of C. tropicalis by 26%, fraction F2 inhibited 35% of the growth of C. buinensis, and fraction F3 inhibited all tested yeasts, exhibiting greater inhibition activity on the growth of the yeast C. albicans (86%) followed by C. buinensis (69%) and C. tropicalis (21%). Fractions F1 and F2 promoted membrane permeabilization of all tested yeasts and increased the endogenous induction of reactive oxygen species (ROS) in C. buinensis and C. tropicalis, respectively. We also observed that fraction F3 at a concentration of 50 µg/mL inhibited the α-amylase activities of Tenebrio molitor larvae by 96% and human salivary by 100%. Thus, our results show that fraction F3, which contains CcDef3, is a very promising protein fraction because it has antifungal potential and is able to inhibit the activity of different α-amylase enzymes.

     

Effects of Parenteral Lipid Infusion on DNA Damage in Very Low Birth Weight Infants

Very low birth weight (VLBW) infants are known to have poorly developed antioxidant system and may be at increased risk for radical damage. Previous studies have reported higher levels of lipid peroxide products in lipid emulsion used for parenteral nutrition. To examine the direct effects of parenteral lipid infusion on DNA damage in VLBW infants, we measured urinary 8-hydroxydeoxyguanosine (8-OHdG) levels in VLBW infants before, during, and after the parenteral lipid infusion. In both the lipid-infused and lipid-free groups, urinary 8-OHdG excretion levels at 14 days old were significantly ( p <0.01) lower than those at 2 and 7 days old. However, there were no significant differences in urinary 8-OHdG excretion levels between the lipid-infused and lipid-free groups at 2, 7, and 14 days old. Our results suggest that parenteral lipid infusion does not cause oxidative DNA damage, but irrespective of the infusion DNA damage during the first week of life is enhanced when compared with 14 days after birth in VLBW infants.     

Synthesis of 2-Alkynylcordycepins and Evaluation of Their Vasodilating Activity

Abstract

Based on the recently developed lithiation-mediated stannyl migration of 6-chloropurine derivatives, 2-iodocordycepin was prepared from cordycepin. The reaction of this compound with terminal alkynes was carried out to synthesize a series of 2-alkynyl derivatives. The vasodilating effect of these compounds was evaluated.     

Preparation of 8-Chloropurine Nucleosides Through the Reaction Between their C-8 Lithiated Species and p-Toluenesulfonyl Chloride

Abstract

Chlorination of purine nucleosides protected with tert-butyldimethylsilyl (TBDMS) group was examined by the reaction of the C-8 lithiated species, generated by LDA, with p-toluenesulfonyl chloride as an electrophile. This provides a new method for the preparation of 8-chloropurine nucleosides.     

Radical-Mediated Cyclization of A 6-Chloro-9-(2-Deoxy--d erythro-pent-1-enofuranosyl)-8-(2,2-dibromovinyl) purine

Abstract

A vinyl radical generated from a 6-chloro-9-(2-deoxy--d eryrhro-pent-l-enofuranosyl)-8-(2,2-dibromovinyl) purine effected cyclization either at the 1′-or at the 2′-position. The result is discussed in comparison with our previous study of the corresponding uracil derivative.     

Apoptosis inhibitor of macrophage (AIM) expression in alveolar macrophages in COPD

Background

Marked accumulation of alveolar macrophages (AM) conferred by apoptosis resistance has been implicated in pathogenesis of chronic obstructive pulmonary disease (COPD). Apoptosis inhibitor of macrophage (AIM), has been shown to be produced by mature tissue macrophages and AIM demonstrates anti-apoptotic property against multiple apoptosis-inducing stimuli. Accordingly, we attempt to determine if AIM is expressed in AM and whether AIM is involved in the regulation of apoptosis in the setting of cigarette smoke extract (CSE) exposure.

Methods

Immunohistochemical evaluations of AIM were performed. Immunostaining was assessed by counting total and positively staining AM numbers in each case (n = 5 in control, n = 5 in non-COPD smoker, n = 5 in COPD). AM were isolated from bronchoalveolar lavage fluid (BALF). The changes of AIM expression levels in response to CSE exposure in AM were evaluated. Knock-down of anti-apoptotic Bcl-xL was mediated by siRNA transfection. U937 monocyte-macrophage cell line was used to explore the anti-apoptotic properties of AIM.

Results

The numbers of AM and AIM-positive AM were significantly increased in COPD lungs. AIM expression was demonstrated at both mRNA and protein levels in isolated AM, which was enhanced in response to CSE exposure. AIM significantly increased Bcl-xL expression levels in AM and Bcl-xL was involved in a part of anti-apoptotic mechanisms of AIM in U937 cells in the setting of CSE exposure.

Conclusions

These results suggest that AIM expression in association with cigarette smoking may be involved in accumulation of AM in COPD.     

Monitoring Escape and Feeding Behaviours of Cruiser Fish by Inertial and Magnetic Sensors

A method was developed and applied for monitoring two types of fast-start locomotion (feeding and escape) of a cruiser fish, Japanese amberjacks Seriola quinqueradiata. A data logger, which incorporated a 3-axis gyroscope, a 3-axis accelerometer and a 3-axis magnetometer, was attached to the five fish. The escape, feeding and routine movements of the fish, which were triggered in tank experiments, were then recorded by the data logger and video cameras. The locomotor variables, calculated based on the high resolution measurements by the data logger (500 Hz), were investigated to accurately detect and classify the types of fast-track behaviour. The results show that fast-start locomotion can be detected with a high precision (0.97) and recall rate (0.96) from the routine movements. Two types of fast-start movements were classified with high accuracy (0.84). Accuracy was greater if the data were obtained from the data logger, which combined an accelerometer, a gyroscope and a magnetometer, than if only an accelerometer (0.80) or a gyroscope (0.66) was used.