Genta Okude

Insects comprise over half of the described species, and the acquisition of metamorphosis must have contributed to their diversity and prosperity. The order Odonata (dragonflies and damselflies) is among the most-ancestral insects with drastic morphological changes upon metamorphosis, in which understanding of the molecular mechanisms will provide insight into the evolution of incomplete and complete metamorphosis in insects. In order to identify metamorphosis-related genes in Odonata, we perfor

We demonstrate that the symbiont of <i>R. dominica</i> constitutes a novel bacterial lineage in the Bacteroidetes. We propose that reductive evolution of the symbiont genome may be relevant to the amorphous morphology of the bacterial cells via disruption of genes involved in cell wall synthesis and cell division. Genomic and functional aspects of the host-symbiont relationship deserve future studies.

The order Odonata (dragonflies and damselflies) comprises diurnal insects with well-developed vision, showing diverse colors in adult wings and bodies. It is one of the most ancestral winged insect groups. Because Odonata species use visual cues to recognize each other, color patterns have been investigated from ecological and evolutionary viewpoints. Here we review the recent progress on molecular mechanisms of pigmentation, especially focused on light-blue coloration. Results from histology an

In an attempt to establish an experimental dragonfly model, we developed a laboratory rearing system for the blue-tailed damselfly, Ischnura senegalensis. Adoption of multi-well plastic plates as rearing containers enabled mass-rearing of isolated larvae without cannibalism and convenient microscopic monitoring of individual larvae. Feeding Artemia brine shrimps to younger larvae and Tubifex worms for older larvae resulted in low mortality, synchronized ecdysis, and normal development of the lar

Abstract Ischnura species (Odonata) are among the most common damselflies in the world, which often exhibit female color polymorphisms. One morph, called androchrome, is similar to males in its color pattern, whereas the other morphs, generally referred to as gynochromes, exhibit female‐specific colors. In several Ischnura species, the female polymorphism is heritable, although molecular and genetic mechanisms remain largely unknown. The dominant‐recessive patterns of the female color morphs may

Thus, mapping and analyzing histone modifications can help identify cis-regulatory elements and accelerate the identification of causative mutations in the non-coding regions underlying naturally occurring phenotypic variations.

Dragonflies and damselflies (order Odonata) represent one of the most ancestral insects with metamorphosis, in which they change their habitat, morphology, and behavior drastically from aquatic larvae to terrestrial/aerial adults without pupal stage. Odonata adults have a well-developed color vision and show a remarkable diversity in body colors and patterns across sexes, stages, and species. While many ecological and behavioral studies on Odonata have been conducted, molecular genetic studies h

The order Odonata (dragonflies and damselflies) is among the most ancestral groups of winged insects with drastic morphological changes upon metamorphosis, and thus important for understanding evo-devo aspects of insects. However, basic developmental descriptions of Odonata have been scarce. In an attempt to establish the foundation of developmental and experimental biology of Odonata, we present an unprecedentedly comprehensive survey of dragonflies and damselflies, in total 158 larvae represen

Interspecific hybrids have been occasionally found in the field. Here were describe a male of the interspecific hybrid between Paracercion sieboldii and P. melanotum with intermediate phenotypes between the two parent species from Japan. Nuclear and mitochondrial DNA analyses indicated that this individual was derived from interspecific mating between a female P. sieboldii and a male P. melanotum. To our knowledge, this is the only report of the hybrid between these two species.

Dragonflies and damselflies (order Odonata) represent one of the most ancestral insects with metamorphosis, in which they change their habitat, morphology, and behavior drastically from aquatic larvae to terrestrial/aerial adults without pupal stage. Odonata adults have a well-developed color vision and show a remarkable diversity in body colors and patterns across sexes, stages, and species. While many ecological and behavioral studies on Odonata have been conducted, molecular genetic studies h

Ecdysteroids are critical in regulating biological processes such as ecdysis, metamorphosis, embryogenesis, and reproduction in insects. Nevertheless, the ecdysteroid repertoire and expression patterns of their synthesis genes in Odonata (dragonflies and damselflies), which belong to the most-ancestral winged insect group, have remained elusive. In this study, we examined the ecdysteroid profile of eight Odonata species and the ecdysteroid fluctuation during metamorphosis in the damselfly Ischnu

Hybridization and introgression frequently occur even between distantly related species. A central question in speciation research is which genomic regions act as barriers to gene flow and how genome-wide differentiation persists despite hybridization between species. Ecological divergence is well known to promote genomic differentiation, especially during the early stages of speciation. However, the extent to which ecological divergence contributes to genomic divergence and the restriction of g