Tracing microbiota changes in yamahai-moto,the traditional Japanese sake starter

Sake is made from steamed rice, malted rice, and water. Sake production begins with the preparation of a small-scale starter (moto); the quality of moto significantly influences the flavor and richness of sake. In the traditional starter, yamahai-moto, the growth of naturally occurring lactic acid bacteria represses the putrefactive micro-organisms, whereas in the modern starter, sokujo-moto, this is achieved by adding lactic acid. In this study, the successive change in bacterial flora of yamahai-moto was analyzed by pyrosequencing 16S ribosomal RNA genes. Lactobacillus was dominant throughout the process (93–98%). Nitrate-reducing bacteria that have been generally assumed to be the first colonizers of yamahai-moto were scarcely found in the early stage, but Lactobacillus acidipiscis dominated. Lactobacillus sakei drastically increased in the middle stage. This is the first report, though one case study, to show how the early stage microbiota in Japanese yamahai-moto is varyingly controlled without nitrate-reducing bacteria using next-generation sequencing.     

FOXO1 delays skeletal muscle regeneration and suppresses myoblast proliferation

Unloading stress, such as bed rest, inhibits the regenerative potential of skeletal muscles; however, the underlying mechanisms remain largely unknown. FOXO1 expression, which induces the upregulated expression of the cell cycle inhibitors p57 and Gadd45α, is known to be increased in the skeletal muscle under unloading conditions. However, there is no report addressing FOXO1-induced inhibition of myoblast proliferation. Therefore, we induced muscle injury by cardiotoxin in transgenic mice overexpressing FOXO1 in the skeletal muscle (FOXO1-Tg mice) and observed regeneration delay in skeletal muscle mass and cross-sectional area in FOXO1-Tg mice. Increased p57 and Gadd45α mRNA levels, and decreased proliferation capacity were observed in C2C12 myoblasts expressing a tamoxifen-inducible active form of FOXO1. These results suggest that decreased proliferation capacity of myoblasts by FOXO1 disrupts skeletal muscle regeneration under FOXO1-increased conditions, such as unloading.     

Characterization of the venom of the vermivorous cone snail Conus fulgetrum

Over 200 components with molecular mass ranging mainly from 400 to 4000 Da were characterized from the venom of the vermivorous cone snail Conus fulgetrum that inhabit Egyptian Red Sea. One major component having a molecular mass of 2946 Da was purified by HPLC, and its primary structure was determined by a combination of Edman degradation and MS/MS analysis.     

Vetch aphid, <Emphasis Type="Italic">Megoura crassicauda</Emphasis> (Hemiptera: Aphididae), parasitism does not reduce the bean production of narrow-leaved vetch, <Emphasis Type="Italic">Vicia sativa</Emphasis> subsp. <Emphasis Type="Italic">nigra</Emphasis> (Fabaceae)

Megoura crassicauda Mordvilko (Hemiptera: Aphididae) is a dominant aphid species found on Vicia sativa subsp. nigra (L.) Ehrh. (Fabaceae) in the spring. Worker ants of Formica japonica, the dominant ant species attracted to the extrafloral nectaries of V. s. nigra, often attack ladybirds (Coccinella septempunctata), which are aphid enemies. However, the workers of F. japonica do not attack or exclude M. crassicauda, the non-myrmecophilous aphid. It appears that the “bodyguard” retained by the plant guards the plant’s herbivore by attacking the herbivores’ enemies, rather than guarding the plant itself. The relationship between V. s. nigra and M. crassicauda was observed in the field to examine and evaluate the cost of parasitism. Parasitism by M. crassicauda delayed flower bud formation markedly in V. s. nigra but did not kill the plants. V. s. nigra plants that were parasitized showed a net bean production similar to that of the non-parasitized controls. The parasitism rate of M. crassicauda increased when extrafloral nectaries were used by F. japonica. These results may indicate that M. crassicauda provides V. s. nigra with benefits by preventing other serious disadvantages.     

Polyploidy does not control all: Lineage‐specific average chromosome length constrains genome size evolution in ferns

Recent studies investigating the evolution of genome size diversity in ferns have shown that they have a distinctive genome profile compared with other land plants. Ferns are typically characterized by possessing medium‐sized genomes, although a few lineages have evolved very large genomes. Ferns are different from other vascular plant lineages as they are the only group to show evidence for a correlation between genome size and chromosome number. In this study, we aim to explore whether the evolution of fern genome sizes is not only shaped by chromosome number changes arising from polyploidy but also by constraints on the average amount of DNA per chromosome. We selected the genus Asplenium L. as a model genus to study the question because of the unique combination of a highly conserved base chromosome number and a high frequency of polyploidy. New genome size data for Asplenium taxa were combined with existing data and analyzed within a phylogenetic framework. Genome size varied substantially between diploid species, resulting in overlapping genome sizes among diploid and tetraploid spleenworts. The observed additive pattern indicates the absence of genome downsizing following polyploidy. The genome size of diploids varied non‐randomly and we found evidence for clade‐specific trends towards larger or smaller genomes. The 578‐fold range of fern genome sizes have arisen not only from repeated cycles of polyploidy but also through clade‐specific constraints governing accumulation and/or elimination of DNA.     

Phylogeography of lethal male fighting in a social spider mite

When males fight for access to females, such conflict rarely escalates into lethal fight because the risks and costs involved, that is, severe injury or death, are too high. The social spider mite, Stigmaeopsis miscanthi, does exhibit lethal male fights, and this male–male aggressiveness varies among populations. To understand the evolution of lethal fighting, we investigated aggressiveness in 42 populations and phylogenetic relationships in 47 populations along the Japanese archipelago. By analysis of the male weapon morph, a proxy for aggressiveness, we confirmed the existence of a mildly aggressive (ML) form, besides the low aggression (LW) and high aggression (HG) forms reported earlier. To evaluate demographic history of these three forms, we employed the approximate Bayesian computation approach using mtCOI sequences and taking into consideration the postlast glacial expansion history of the host plant, Miscanthus sinensis. As results, hierarchical split models are more likely to explain the observed genetic pattern than admixture models, and the ML form in the subtropical region was considered the ancestral group. The inferred demographic history was consistent with the one reconstructed for the host plant in a previous study. The LW form was split from the ML form during the last glacial period (20,000–40,000 years BP), and subsequently, the HG form was split from the ML form at the end of or after the last glacial period (5,494–10,988 years BP). The results also suggest that the mite invaded Japan more than once, resulting in the present parapatric distribution of LW and HG forms in eastern Japan.     

Acoustic emissions of Sorex unguiculatus (Mammalia: Soricidae): Assessing the echo‐based orientation hypothesis

Shrew species have been proposed to utilize an echo‐based orientation system to obtain additional acoustic information while surveying their environments. This system has been supported by changes in vocal emission rates when shrews encounter different habitats of varying complexity, although detailed acoustic features in this system have not been reported. In this study, behavioral experiments were conducted using the long‐clawed shrew (Sorex unguiculatus) to assess this orientation system. Three experimental conditions were set, two of which contained obstacles. Short‐click, noisy, and different types of tonal calls in the audible‐to‐ultrasonic frequency range were recorded under all experimental conditions. The results indicated that shrews emit calls more frequently when they are facing obstacles or exploring the experimental environment. Shrews emitted clicks and several different types of tonal calls while exploring, and modified the use of different types of calls for varying behavior. Furthermore, shrews modified the dominant frequency and duration of squeak calls for different types of obstacles, that is, plants and acrylic barriers. The vocalizations emitted at short inter‐pulse intervals could not be observed when shrews approached these obstacles. These results are consistent with the echo‐based orientation hypothesis according to which shrews use a simple echo‐orientation system to obtain information from their surrounding environments, although further studies are needed to confirm this hypothesis.     

Sequential Ubiquitination of Ribosomal Protein uS3 Triggers the Degradation of Non-functional 18S rRNA

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