Effect of paternal age on the birth sex ratio in captive populations of aye‐aye (Daubentonia madagascariensis (Gmelin))

For the management of captive populations of zoo animals, it is important to elucidate factors that affect the offspring birth sex ratio. On the basis of the sex allocation theory, the Trivers–Willard and mate attractive/quality hypotheses predict that maternal and paternal conditions affect offspring birth sex ratios. We examined these predictions for the birth sex ratio of aye‐aye Daubentonia madagascariensis (Gmelin) by analyzing the pedigree information in the International Studbook. We found that the birth sex ratio of the aye‐aye was affected by the paternal age, but not maternal age and other environmental factors (birth year, season, and institution). The younger the sire, the more the offspring sex ratio was biased toward males. These results are useful for the effective population management of captive aye‐aye and illustrated the usefulness of the sex allocation theory in the sex ratio management of zoo animals.     

Araneophagic behavior of Gardena brevicollis Stål (Heteroptera: Reduviidae): Foraging on pre‐dispersal spiderlings in the spider's web

Araneophagic behavior of an Emesinae assassin bug, Gardena brevicollis Stål (Hemiptera: Reduviidae) was observed in the field. The bug invaded a web of Acusilas coccineus Simon (Araneae: Araneidae) spiderlings and hunted five juvenile spiders. The bug showed stalking tactics to prey on spiders, whereas luring tactics, which have been reported in other Emesinae bugs, were not observed. To the best of my knowledge, the present study is the first report of araneophagy in the genus Gardena and the first report of araneophagic behavior in East Asian assassin bugs.     

Acclimation to seawater allows activation of spermatozoa of a euryhaline fish Oryzias latipes

Environmental Biology of Fishes - Medaka Oryzias latipes is a tiny euryhaline fresh water fish distributed in environments differing widely in salinity. According to past reports, Oryzias latipes...     

Economic costs of invasive alien ants worldwide

Biological Invasions - Invasive ants are amongst the most destructive and widespread invaders across the globe; they can strongly alter invaded ecosystems and are responsible for the loss of native...     

Actively growing bacteria in the inland sea of Japan, identified by combined bromodeoxyuridine immunocapture and denaturing gradient gel electrophoresis

A fundamental question in microbial oceanography concerns the relationship between prokaryote diversity and biogeochemical function in an ecosystem context. We combined bromodeoxyuridine (BrdU) magnetic bead immunocapture and PCR-denaturing gradient gel electrophoresis (BUMP-DGGE) to examine phylotype-specific growth in natural marine assemblages. We also examined a broad range of marine bacterial isolates to determine their abilities to incorporate BrdU in order to test the validity of the method for application to diverse marine assemblages. We found that 27 of 29 isolates belonging to different taxa could incorporate BrdU. BUMP-DGGE analysis revealed phylogenetic affiliations of DNA-synthesizing, presumably actively growing bacteria across a eutrophic to mesotrophic transect in the Inland Sea of Japan. We found that the BrdU-incorporating (growing) communities were substantially different from the total communities. The majority (34/56) of phylotypes incorporated BrdU and were presumably growing, and these phylotypes comprised 10 alphaproteobacteria, 1 betaproteobacterium, 11 gammaproteobacteria, 11 Cytophaga-Flavobacterium-Bacteroides group bacteria, and 1 unclassified bacterium. All BrdU-responsive alphaproteobacteria were members of the Rhodobacterales, suggesting that such bacteria were dominant in the growing alphaproteobacterial populations in our samples. The BrdU-responsive gammaproteobacteria belonged to the Oceanospirillales, the SAR86 cluster, the Pseudomonadales, the Alteromonadales, and the Vibrionales. Thus, contemporaneous cooccurrence of diverse actively growing bacterial taxa was a consistent pattern in our biogeochemically varied study area.     

Characterization of Fusarium oxysporum beta-1,6-galactanase, an enzyme that hydrolyzes larch wood arabinogalactan

A type II arabinogalactan-degrading enzyme (FoGal1) was purified from Fusarium oxysporum 12S, and the corresponding cDNA was isolated. FoGal1 had high similarity to enzymes of glycoside hydrolase family 5. Treatment of larch wood arabinogalactan with the recombinant enzyme indicated that FoGal1 is a beta-1,6-galactanase that preferentially debranches beta-1,6-galactobiose from the substrate.     

Reaction of retinol with peroxynitrite

The reactivity of retinol with peroxynitrite, which is a strong oxidant and has been reported to induce several biological damages, was investigated. 13-cis-14-nitroretinol (1), 13-trans-14-nitroretinol (2), 13-apo-beta-carotenone (3), retinal (4), 11,14-epoxyretinol (5), and 11,15-epoxyretinol (6) were identified as reaction products of retinol with peroxynitrite. From these results, it was observed that retinol can undergo a nitration reaction with peroxynitrite. Furthermore, the formation mechanisms of 1, 2, and 3 from retinol with peroxynitrite are discussed.     

Functional Characterization of 5-Oxoproline Transport via SLC16A1/MCT1

Thyrotropin-releasing hormone is a tripeptide that consists of 5-oxoproline, histidine, and proline. The peptide is rapidly metabolized by various enzymes. 5-Oxoproline is produced by enzymatic hydrolysis in a variety of peptides. Previous studies showed that 5-oxoproline could become a possible biomarker for autism spectrum disorders. Here we demonstrate the involvement of SLC16A1 in the transport of 5-oxoproline. An SLC16A1 polymorphism (rs1049434) was recently identified. However, there is no information about the effect of the polymorphism on SLC16A1 function. In this study, the polymorphism caused an observable change in 5-oxoproline and lactate transport via SLC16A1. The Michaelis constant (K_m) was increased in an SLC16A1 mutant compared with that in the wild type. In addition, the proton concentration required to produce half-maximal activation of transport activity (K_{0.5, H}⁺) was increased in the SLC16A1 mutant compared with that in the wild type. Furthermore, we examined the transport of 5-oxoproline in T98G cells as an astrocyte cell model. Despite the fact that 5-oxoproline is an amino acid derivative, Na⁺-dependent and amino acid transport systems scarcely contributed to 5-oxoproline transport. Based on our findings, we conclude that H⁺-coupled 5-oxoproline transport is mediated solely by SLC16A1 in the cells.     

Bif-1 interacts with Beclin 1 through UVRAG and regulates autophagy and tumorigenesis

Autophagy is an evolutionarily conserved 'self-eating' process. Although the genes essential for autophagy (named Atg) have been identified in yeast, the molecular mechanism of how Atg proteins control autophagosome formation in mammalian cells remains to be elucidated. Here, we demonstrate that Bif-1 (also known as Endophilin B1) interacts with Beclin 1 through ultraviolet irradiation resistance-associated gene (UVRAG) and functions as a positive mediator of the class III PI(3) kinase (PI(3)KC3). In response to nutrient deprivation, Bif-1 localizes to autophagosomes where it colocalizes with Atg5, as well as microtubule-associated protein light chain 3 (LC3). Furthermore, loss of Bif-1 suppresses autophagosome formation. Although the SH3 domain of Bif-1 is sufficient for binding to UVRAG, both the BAR and SH3 domains are required for Bif-1 to activate PI(3)KC3 and induce autophagosome formation. We also observed that Bif-1 ablation prolongs cell survival under starvation conditions. Moreover, knockout of Bif-1 significantly enhances the development of spontaneous tumours in mice. These findings suggest that Bif-1 joins the UVRAG-Beclin 1 complex as a potential activator of autophagy and tumour suppressor.