Toru Miura

• Ph.D.
• Professor (Full) at The University of Tokyo

The shorelines of Japan host diverse ecosystems, particularly in the shallow coastal waters, which are rich in syllid species. This study describes two new Syllidae species: Virchowia christophi sp. nov., discovered at Misaki and Sugashima Island, and Paraopisthosyllis rufa sp. nov., found at Misaki. Additionally, we provide a redescription of Syll...

Background Ramisyllis kingghidorahi (Annelida, Syllidae) is one of few annelid species with a ramified body, one anterior end and hundreds of posterior ends. R. kingghidorahi belongs to the family Syllidae, whose members reproduce by forming stolons, small autonomous reproductive units, at the posterior end. Molecular mechanisms controlling sexual...

Phenotypic plasticity, the ability of organisms to change their phenotype depending on external stimuli, enables their survival in fluctuating environments. An extreme example is polyphenism, in which a single genotype produces discrete phenotypes in response to external cues. However, under persistent environmental conditions, natural selection wo...

Background The acquisition of air-breathing organs is one of the key innovations for terrestrialization in animals. Terrestrial isopods, a crustacean lineage, can be interesting models to study the evolution of respiratory organs, as they exhibit varieties of air-breathing structures according to their habitats. However, the evolutionary processes...

Background Various morphological adaptations are associated with symbiotic relationships between organisms. One such adaptation is seen in the nemertean genus Malacobdella. All species in the genus are commensals of molluscan hosts, attaching to the surface of host mantles with a terminal sucker. Malacobdella possesses several unique characteristic...

Benthic annelids belonging to the family Syllidae show a distinctive sexual reproduction mode called “stolonization,” in which posterior segments are transformed into a reproductive individual‐like unit called a “stolon.” Megasyllis nipponica forms a stolon head and a secondary tail in the middle of the trunk before a stolon detaches, while, in the...

Background The acquisition of air-breathing organs is one of the key innovations for terrestrialization in animals. Terrestrial isopods, a crustacean lineage, can be suitable models to study the evolution of respiratory organs, as they exhibit varieties of air-breathing structures according to their habitats. However, the evolutionary processes and...

Many species of sea cucumbers (Echinodermata, Holothuroidea) perform evisceration, i.e., ejection of internal organs including digestive tracts when responding to environmental stresses. After evisceration, they also show a high regenerative capacity, in which all the eviscerated organs regenerate. Especially in anterior evisceration species, the o...

The harlequin sandsmelt (Parapercis pulchella) is a female-to-male sex change fish in which functional females possess ovotestes that consist of both ovarian and testicular tissues. These features indicate that this species could be an excellent model for studying the flexibility of sex differentiation in vertebrates. However, genetic resources in...

Benthic annelids belonging to the family Syllidae (Annelida, Errantia, Phyllodocida) exhibit a unique reproduction mode called “schizogamy” or “stolonization”, in which the posterior body part filled with gametes detaches from the original body, as a reproductive unit (stolon) that autonomously swims and spawns. In this study, morphological and his...

In many crustacean species, an individual possesses both uniramous and biramous appendages that enable us to compare the two types on the same genetic background. Therefore, among the diverse morphologies of arthropod appendages, crustacean biramous appendages provide interesting subjects for studying the developmental mechanisms underlying appenda...

Some teleost fishes change their sex, and some of these fishes have specific gonads known as “ovotestes,” that is, gonads containing both ovarian and testicular tissues. In this study, we revealed the gonadal transformation process and cell dynamics during the female‐to‐male sex change in the harlequin sandsmelt, Parapercis pulchella (Pinguipetidae...

Morphologies of animal appendages are highly diversified depending on animal lifestyles. In cephalopods (Mollusca, Cephalopoda), an individual possesses multiple arms that contribute to elaborate behaviors, and suckers on them enable various arm functions. In octopus hatchlings, arm and sucker morphologies can be divided into two different types du...

Benthic annelids belonging to the family Syllidae (Errantia, Phyllodocida) exhibit a unique reproduction mode called “schizogamy” or “stolonization”, in which the posterior body part filled with gametes detaches from the original body, as a reproductive unit (stolon) that autonomously swims and spawns. In this study, detailed developmental processe...

Background In social insects, interactions among colony members trigger caste differentiation with morphological modifications. In termite caste differentiation, caste-specific morphologies (such as mandibles in soldiers, genital organs in reproductives or wings in alates) are well developed during post-embryonic development under endocrine control...

In some species of termites, a part of nymphs can undergo “regressive molt,” in which imaginal characters such as wing buds and body size are reduced. The function of regressive molt is thought to be a regulatory mechanism controlling caste composition in a colony. However, little is known about the physiological and developmental processes resulti...

Background Arthropods gradually change their forms through repeated molting events during postembryonic development. Anamorphosis, i.e., segment addition during postembryonic development, is seen in some arthropod lineages. In all millipede species (Myriapoda, Diplopoda), for example, postembryonic processes go through anamorphosis. Jean-Henri Fabr...

During evolution, various lineages of arthropods colonized land and independently acquired air-breathing organs. Some taxa of oniscidean isopods (Crustacea, Isopoda, Oniscidea) are the most successful crustacean lineages on land and possess organs called “lungs” or “pseudotrachea” for air-breathing in their abdominal appendages, i.e., in pleopods....

Understanding the processes and consequences of the morphological diversity of organisms is one of the major goals of evolutionary biology. Studies on the evolution of developmental mechanisms of morphologies, or evo-devo, have been extensively conducted in many taxa and have revealed many interesting phenomena at the molecular level. However, many...

Despite being one of the bilaterians, the body plan of echinoderms shifts from bilateral symmetry to five-fold radial, or pentaradial symmetry during embryogenesis or their metamorphosis. While the clarification of the developmental mechanism behind this transition will be a basis for understanding their unique body plan evolution, it is still poor...

In sexual dimorphism, males often exhibit exaggerated characters as weapons or ornaments. Among the numerous amphipod species (Amphipoda, Crustacea) showing sexual dimorphism, caprellids (Caprellidae) are characterized by considerably larger males that possess weapons, although the developmental processes underlying these sex-related differences ar...

The organization of social insect colonies requires sophisticated mechanisms to regulate caste composition according to colony demands. In termites, the soldier caste is responsible for the inhibition of soldier differentiation, but the mechanism underlying the regulation of soldier differentiation is still unclear. In this study, we performed tran...

Echinoderms constitute an animal phylum characterized by the pentaradial body plan. During the development from bilateral larvae to pentaradial adults, the formation of the multiple of five hydrocoel lobes, i.e., the buddings from the mesodermal coelom, is the firstly emerging pentameral character. The developmental mechanism underlying the hydroco...

Most animal species spend their lives in a form based on the unit of “an individual” that is a sophisticated multicellular closed unit with various biological functions. Although the system of an animal individual seems to be perfect, individuals belonging to some animal lineages constitute higher-dimensional units, i.e., colonies, that consist of...

Four new species of annelids, Ctenodrilus japonicus sp. nov., Raphidrilus misakiensis sp. nov., Raphidrilus okinawaensis sp. nov., and Raricirrus anubis sp. nov., are described based on specimens collected from Japanese waters. Ctenodrilus japonicus sp. nov. inhabits the interstitial environment and can be distinguished from the other congeners by...

Caste development in social insects requires the coordination of molting and metamorphosis during postembryonic development. In termites, i.e., hemimetabolous eusocial insects, caste fate is determined during postembryonic development. However, it is not fully understood how the mechanisms of molting/metamorphosis are regulated in the course of dif...

Among over 20,000 species of Annelida, only two branching species with a highly modified body-pattern are known until now: the Syllidae Syllis ramosa McIntosh, 1879, and Ramisyllis multicaudata Glasby et al. (Zoological Journal of the Linnean Society, 164, 481–497, 2012). Both have unusual ramified bodies with one head and multiple branches and liv...

Significance Gene duplication is a major source of evolutionary innovation and is associated with the increases in biological complexity and adaptive radiation. Termites are model social organisms characterized by a sophisticated caste system. We analyzed the genome of the Japanese subterranean termite, an ecologically and economically important in...

Echinoderms constitute an animal phylum characterized by the pentaradial body plan. During the development from bilateral larvae to pentaradial adults, the formation of the multiple of five hydrocoel lobes, i.e., the buddings from the mesodermal coelom, is the firstly emerging pentameral character. The developmental mechanism underlying the hydroco...

Cephalopods have acquired numerous novelties and expanded their habitats to various marine environments as highly agile predators. Among cephalopod novelties, multiple arms are used for complex behaviors, including prey capture. Suckers on arms are innovative features for realizing these arm functions. In addition, tentacles in Decapodiformes (squi...

Although many animals that perform sexual reproduction exhibit sexual dimorphism, individuals with intersex traits between the traits of males and females appear in some species, depending on environmental factors. Ptychognathus ishii, a varunid crab, exhibits distinctive sexual dimorphism in the morphology of its abdomen, chelipeds and setal tufts...

Termites are model social organisms characterized by a polyphenic caste system. Subterranean termites (Rhinotermitidae) are ecologically and economically important species, including acting as destructive pests. Rhinotermitidae occupies an important evolutionary position within the clade representing an intermediate taxon between the higher (Termit...

Convergent evolution of eusociality with the division of reproduction and its plastic transition in Hymenoptera has long attracted the attention of researchers. To explain the evolutionary scenario of the reproductive division of labor, several hypotheses had been proposed. Among these, we focus on the most basic concepts, i.e., the ovarian ground...

Eusocial insects exhibit reproductive division of labor, in which only a part of colony members differentiates into reproductives. In termite colonies, the division of labors is performed among multiple types of individuals (i.e., castes), such as reproductives, workers, and soldiers to organize their society. Caste differentiation occurs according...

In bryozoans (phylum Bryozoa), representative colonial animals mostly found in marine environments, some species possess different types of individuals (heterozooids) specialized in different functions such as defense or structural support for their colonies. Among them, the best-known heterozooids are the avicularia, known to function as defenders...

In eusocial insect colonies, non-reproductive workers often perform different tasks. Tasks of an individual worker are shifted depending on various factors, e.g., age and colony demography. Although a vitellogenin (Vg) gene play regulatory roles in both reproductive and non-reproductive division of labours in a honeybee, it has been shown that the...

Basket stars, that is, Ophiuroidea in Echinodermata, exhibit distinctive morphological characteristics with their complicatedly branched arms that can regenerate immediately after mutilation. Although, in brittle stars, that is, ophiuroids with nonbranched arms, the arm regeneration process following accidental trauma or autotomy have been morpholo...

Tiny annelids identified as the marine meiobenthic polychaete Dinophilus gyrociliatus (Schmidt, 1857) have been reported not only from shallow water sediments but also artificial environments such as experimental aquaria almost all around the world; the species has thus been regarded to show a cosmopolitan distribution. However, various types of ci...

Background: Morphological novelties have been acquired through evolutionary processes and related to the adaptation of new life-history strategies with new functions of the bodyparts. Cephalopod molluscs such as octopuses, squids and cuttlefishes possess unique morphological characteristics. Among those novel morphologies, in particular, suckers a...

As a supramolecular micromachine with information flow, a giant vesicle (GV)-based artificial cell that exhibits a linked proliferation between GV reproduction and internal DNA amplification has been explored in this study. The linked proliferation is controlled by a complex consisting of GV membrane-intruded DNA with acidic amphiphilic catalysts,...

Eusocial insects exhibit reproductive division of labor, in which only a fraction of colony members differentiate into reproductives. In termites, reproductives of both sexes are present in a colony and constantly engaged in reproduction. It has been suggested that the sex ratio of reproductives is maintained by social interactions. The presence of...

Background : Morphological novelties have been acquired through evolutionary processes in relation to the acquisition of new life-history strategies together with novel functions of bodyparts. Cephalopod molluscs such as octopuses, squids and cuttlefishes possess novel morphological characteristics such as their overall bodyplans and numerous arms....

Background : Morphological novelties have been acquired through evolutionary processes and related to the adaptation of new life-history strategies with new functions of the bodyparts. Cephalopod molluscs such as octopuses, squids and cuttlefishes possess unique morphological characteristics. Among those novel morphologies, in particular, suckers a...

Termites (Blattodea, Termitoidea, or Isoptera) constitute one of the major lineages of eusocial insects. In termite societies, multiple types of functional individuals, that is, castes, perform divisions of labors to coordinate social behaviors. Among other castes, the soldier caste is distinctive since it is sterile and exclusively specialized int...

Why workers forfeit direct reproduction is a crucial question in eusocial evolution. Worker reproduction provides an excellent opportunity to understand the mechanism of kin conflict resolution between the queen and workers. We evaluated behavioral and physiological differences among females in the paper wasp Polistes chinensis antennalis to examin...

Eusocial insects organize their colonies based on division of labor and caste differentiation, in which caste-specific morphologies are sculpted during postembryonic development. In the differentiation between reproductive and sterile castes, characteristics related to mating and reproduction are developed in reproductives, and degenerated in neute...

Cladobranchian sea slugs are characterized by a number of dorsal projections, called "cerata," which are presumably involved in such biological functions as kleptocnidal defense, gas exchange, and symbiotic photosynthesis. Here, we investigated the developmental pattern of ceras formation in a cladobranchian, Pteraeolidia semperi, using field-colle...

Some polychaete species in the family Syllidae exhibit distinctive life cycles, in which a posterior part of the body of an individual detaches as a reproductive individual called a “stolon”. This type of reproductive mode is known as stolonization or schizogamy. Although a number of observations have been reported, and techniques using molecular m...

In the evolutionarily-derived termite subfamily Nasutitermitinae (family Termitidae), soldiers defend their nestmates by discharging polycyclic diterpenes from a head projection called the "nasus." The diterpenes are synthesised in the frontal gland from the precursor geranylgeranyl diphosphate (GGPP), which is generally used for post-translational...

Background: Generally in termites, alates differentiate through multiple nymphal instars which gradually develop wing buds. However, in a dampwood termite, Hodotermopsis sjostedti, alates molt directly from a single nymphal instar with short wing buds. In this study, to examine the mechanism underlying the wing formation during the alate different...

In social insects, interactions among colony members trigger caste differentiation with morphological modifications. In termite soldier differentiation, the mandible size considerably increases through two moltings (via the presoldier stage) under the control of juvenile hormone (JH). Regulatory genes are predicted to provide patterning information...

Background Aphids display “cyclic parthenogenesis,” in which parthenogenetically and sexually reproducing morphs seasonally alternate in the aphid annual life cycles. There are various characteristics that differ between asexual viviparous and sexual oviparous females. In oviparous females, swollen cuticular structures (~ 10 μm in diameter), called...

Phenotypic plasticity and polyphenism, in which phenotypes can be changed depending on environmental conditions, are common in insects. Several studies focusing on physiological, developmental, and molecular processes underlying the plastic responses have revealed that similar endocrine mechanisms using juvenile hormone (JH) are used to coordinate...

Eusocial insects have polyphenic caste systems in which each caste exhibits characteristic morphology and behavior. In insects, caste systems arose independently in different lineages, such as Isoptera and Hymenoptera. Although partial molecular mechanisms for the development of eusociality in termites have been clarified by the functional analysis...

The wood-feeding cockroach genus Cryptocercus is a subsocial and sister group of the eusocial cockroaches, i.e., termites. Although Cryptocercus is a key taxon for understanding the evolution of eusociality in the Blattodea (cockroaches and termites), few genetic resources are available for comparative genetic analyses. In this study, we conducted...

The wood-feeding cockroach genus Cryptocercus is a subsocial and sister group of the eusocial cock- roaches, i.e., termites. Although Cryptocercus is a key taxon for understanding the evolution of eusociality in the Blattodea (cockroaches and termites), few genetic resources are available for comparative genetic analyses. In this study, we conducte...

In cooperative societies such as those of ants, honey bees, and termites, the number of reproductives is often regulated by social interactions. In many termite species, helper individuals (i.e., larvae or workers) can potentially differentiate into a “neotenic” reproductive caste in the absence of reproductives. In some termite species, multiple n...

Objective: Animals, including arthropods, are one health threat that can be affected by disasters. This institution-based study aimed to assess trends in Hymenoptera stings following the 2011 Fukushima nuclear disaster. Methods: We reviewed the medical records of patients with hymenopteran stings who visited Minamisoma Municipal General Hospital...

Sex-specific genetic markers are often required for studying sex-associated phenomena. Restriction site-associated DNA sequencing (RAD-seq) allows detection of a huge number of genetic polymorphisms and is particularly useful for identifying sex-specific DNA-based (or molecular) genetic markers. Although sex determination in the Japanese subterrane...

Juvenile hormone (JH) plays a crucial role in the determination of developmental timing in insects. In Drosophila melanogaster, reports indicate that JH titers are the highest immediately following eclosion and that the mating experience increases the titers in females. However, the titers have not been successively measured for an extended period...

How individual organisms whose behavior is potentially driven by selfish interests cooperate to form a society is a central question in evolutionary biology. Worker reproduction and its suppression in eusocial insects provide an illuminating model of such a conflict resolution. Although many theoretical and empirical studies focus on the nature and...

One of the defining features of the evolutionary success of insects is the morphological diversification of their appendages, especially mouthparts. Although most insects share a common mouthpart ground plan, there is remarkable diversity in the relative size and shapes of these appendages among different insect lineages. One of the most prominent...

Tardigrades, also known as water bears, are small aquatic animals. Some tardigrade species tolerate almost complete dehydration and exhibit extraordinary tolerance to various physical extremes in the dehydrated state. Here we determine a high-quality genome sequence of Ramazzottius varieornatus, one of the most stress-tolerant tardigrade species. P...

Pathway enrichment analysis of lost genes

Annotations and expression profiles of the final gene model of R. varieornatus

Selective expansion in stress-related gene family

Selective loss of peroxisomal oxidative pathway

Selective loss of stress-responsive mTORC1 regulatory pathway

Supplementary Figures 1-22, Supplementary Tables 1-15 and Supplementary Methods

Summary of assembled scaffolds

The catecholamine dopamine plays several vital roles in the central nervous system of many species, but its neural mechanisms remain elusive. Detailed neuroanatomical characterization of dopamine neurons is a prerequisite for elucidating dopamine's actions in the brain. In the present study, we investigated the distribution of dopaminergic neurons...

One of the principal features of eusocial insect societies is the reproductive division of labor, which involves developmental regulation of the reproductive organs. However, although the regulation of caste development is important for establishing social structure in termites, one of the major eusocial insect groups, little is known about reprodu...

The Hokkaido salamander (Hynobius retardatus) is endemic to Hokkaido Island, Japan, and shows intriguing flexible phenotypic plasticity and regional morphological diversity. However, to date, allozymes and partial mitochondria DNA sequences have provided only an outline of its demographic histories and the pattern of its genetic diversification. To...

Allele frequency and sample size by population. (XLSX)

Pairwise FST (below the diagonal) and DA (above the diagonal) distances between populations. (XLSX)

Genotyping data as genepop format. (XLSX)

Estimated rates of gene flow between populations inferred by BAYESASS+ and MIGRATE-N. (XLSX)

Properties of 12 microsatellite loci in the Hokkaido salamander. (XLSX)

In termites, i.e. a major group of eusocial insects, the soldier caste exhibits specific morphological characteristics and extremely high aggression against predators. Although the genomic background is identical to the other non-aggressive castes, they acquire the soldier-specific behavioral character during the course of caste differentiation. Th...

Examples of the original trace for the HPLC measurements. HPLC traces of a soldier and a pseudergates are shown by black and grey lines. The peaks of a chemical are identified as octopamine (OA), 3, 4-dihydroxybenzylamine (DHBA), dopamine (DA), B-acetyltyramine (NATA), tyramine (TA), tryptophan (Trp), and 5-hydroxytryptamine (5-HT). (EPS)

The standardized levels of biogenic amines in soldiers and pseudergates. Tyramine (A), octopamine (B), dopamine (C) and 5-HT (D) levels in pseudergates (light grey) and soldiers (dark grey) (N = 23 each). The circles indicate the aminergic levels in each termite individual. Box plots show median values (solid horizontal line), 50th percentile value...

Projection pattern of TA-l-ir neurons in pseudergates. Immunostaining using an anti-tyramine antibody identified TA-l-ir neurons and their fibers. (AVI)

Sizes of brain and SOG in Hodotermopmsis sjostedti [29]. (DOC)