epigenetic insect

Plants need to cope with changing environmental conditions, be it variable light or temperature, different availability of water or nutrients, or attack by pathogens or insects. Some of these changing conditions can become stressful and require strong countermeasures to ensure plant survival. Plants have evolved numerous distinct sensing and signalling mechanisms to perceive and respond appropriately to a variety of stresses. Because of the unpredictable nature of numerous stresses, resource-saving stress response mechanisms are inducible and become activated only upon a stress experience...

Recent concepts in evolutionary biology suggest that epigenetic mechanisms can translate environmental selection pressures into heritable changes in phenotype. To determine whether experimental selection for a complex trait in insects involves epigenetic modifications, we carried out a generation-spanning experiment using larvae of the greater wax moth Galleria mellonella as a model host to investigate the role of epigenetics in the heritability of resistance against the parasitic fungus Metarhizium robertsii...

Chromosomal imprinting requires an epigenetic system that "imprints" one of the two parental chromosomes such that it results in a heritable (cell-to-cell) change in behavior of the "imprinted" chromosome. Imprinting takes place when the parental genomes are separate, which occurs during gamete formation in the respective germ-lines and post-fertilization during the period when the parental pro-nuclei lie separately within the ooplasm of the zygote. In the mouse, chromosomal imprinting is regulated by germ-line specific DNA methylation...

DNA methylation is one of the most widespread epigenetic marks and has been linked to insect development, especially influencing embryonic development. However, the regulation of DNA methylation in silkworm embryonic development and diapause remain to investigate. In this study, reverse-transcription quantitative polymerase chain reaction was performed to identify the expression level of Bombyx mori DNA methyltransferases (BmDNMTs) 1 and 2 ( BmDnmt1 and BmDnmt2) in different tissues, different embryonic developmental stages, and different strains of the silkworm...

BACKGROUND: Epigenetic modifications including DNA methylation and post-translational modifications of histones are known to regulate gene expression. Antagonistic activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs) mediate transcriptional reprogramming during insect development as shown in Drosophila melanogaster and other insects. Juvenile hormones (JH) play vital roles in the regulation of growth, development, metamorphosis, reproduction and other physiological processes...

Heliothis zea nudivirus-1 (HzNV-1) is an insect virus that can induce both lytic and latent infections in various insect cell lines. During latent infection, several microRNAs (miRNAs) are produced from persistency-associated gene 1 (pag1) as the only detectable HzNV-1 transcript. Previous studies have shown that the pag1 gene suppresses the immediate-early gene hhi1 and promotes host switching into a latent infection via miRNAs derived from pag1. Although other functions of the miRNAs derived from pag1 have not yet been elucidated, several studies have suggested that miRNAs encoded from latency-associated genes can regulate histone-associated enzymes...

For many insects, diapause is the primary mechanism for surviving unfavorable seasons. Some aspects of diapause regulation are well known, but we still lack a mechanistic understanding of molecular mechanisms that control the diapause pathway. Accumulating evidence suggests microRNAs regulate diapause in evolutionarily diverse insect species including flesh flies and moths, and, it is likely that microRNAs regulate multiple characteristics of diapause, including arrested egg follicle development and fat hypertrophy, in females of the Northern house mosquito, Culex pipiens...

For over a century, biologists have proposed a role for phenotypic plasticity in evolution, providing an avenue for adaptation in addition to 'mutation-first' models of evolutionary change. According to the various versions of this idea, the ability of organisms to respond adaptively to their environment through phenotypic plasticity may lead to novel phenotypes that can be screened by natural selection. If these initially environmentally induced phenotypes increase fitness, then genetic accommodation can lead to allele frequency change, influencing the expression of those phenotypes...

Oncopeltus fasciatus males fed the ancestral diet of milkweed seeds prioritize reproduction over lifespan as evidenced by higher rates of fertility and shorter lifespans than males from the same population fed the adapted diet of sunflower seeds. We examined the proximate mechanisms by which milkweed-fed males maintained late-life fertility. We tested the hypothesis that older milkweed-fed males maintained fertility by producing more, higher quality sperm. Our results, that older males have more sperm, but their sperm do not have higher viability, are in general agreement with other recent studies on how nutrition affects male fertility in insects...

Served as a model organism over a century, fruit fly has significantly pushed forward the development of global scientific research, including in China. The high similarity in genomic features between fruit fly and human enables this tiny insect to benefit the biomedical studies of human diseases. In the past decades, Chinese biologists have used fruit fly to make numerous achievements on understanding the fundamental questions in many diverse areas of biology. Here, we review some of the recent fruit fly studies in China, and mainly focus on those studies in the fields of stem cell biology, cancer therapy and regeneration medicine, neurological disorders and epigenetics...

Epigenetic mechanisms, such as CpG DNA methylation enable phenotypic plasticity and rapid adaptation to changing environments. CpG DNA methylation is established by DNA methyltransferases (DNMTs), which are well conserved across vertebrates and invertebrates. There are insects with functional DNA methylation despite lacking a complete set of Dnmts. But at least one of the enzymes, DNMT1, appears to be required to maintain an active DNA methylation system. The red flour beetle, Tribolium castaneum, lacks Dnmt3 but possesses Dnmt1 and it has been controversial whether it has a functional DNA methylation system...

The idea that the fitness value of body coloration may be affected by biochemically mediated trade-offs has received much research attention. For example, melanization is believed to interact with other fitness-related traits via competition for substrates, costs associated with the synthesis of melanin or pleiotropic effects of the involved genes. However, genetic correlations between coloration and fitness-related traits remain poorly understood. Here, we present a quantitative-genetic study of a coloration trait correlated to melanin-based cuticular darkness ('darkness', hereafter) in a geometrid moth, Ematurga atomaria...

Collective evidence from agricultural practices and from scientific research has demonstrated that plants can alter their phenotypic responses to repeated biotic and abiotic stresses or their elicitors. A coordinated reaction at the organismal, cellular and genome levels have suggested that plants can "remember" an earlier stress and modify their future responses, accordingly. Stress memory may increase a plant's survival chances by improving its tolerance/avoidance abilities and may provide a mechanism for acclimation and adaptation...

Epigenetic inheritance is fundamentally important to cellular differentiation and developmental plasticity. In this review, we provide an introduction to the field of molecular epigenetics in insects. Epigenetic information is passed across cell divisions through the methylation of DNA, the modification of histone proteins, and the activity of noncoding RNAs. Much of our knowledge of insect epigenetics has been gleaned from a few model species. However, more studies of epigenetic information in traditionally nonmodel taxa will help advance our understanding of the developmental and evolutionary significance of epigenetic inheritance in insects...

Noncoding RNAs play essential functions during epigenetic regulation of gene expression and development in numerous organisms. Three type of small noncoding RNAs found in eukaryotes, which are small interfering RNAs (siRNAs), microRNAs (miRNAs) and piwi-interacting RNAs (piRNAs). Small RNAs (sRNAs) originated from infecting viruses are known as virus-derived small interfering RNAs (vsiRNAs), are responsible for RNA silencing in plants. However, Virus-induced gene silencing (VIGS) is mainly dependent on RNA silencing (RNAi)...

Hyperplasia and hypertrophy are elements of phenotypic plasticity adjusting organ size and function. Because they are costly, we assume that they are beneficial. In this review, the authors discuss examples of tissue and organ systems that respond with plastic changes to osmotic stress to raise awareness that we do not always have sufficient experimental evidence to conclude that such processes provide fitness advantages. Changes in hydranth architecture in the hydroid Cordylophora caspia or variations in size in the anal papillae of insect larvae upon changes in medium salinity may be adaptive or not...

DNA methylation is an evolutionary ancient epigenetic modification that is phylogenetically widespread. Comparative studies of the methylome across a diverse range of non-conventional and conventional model organisms is expected to help reveal how the landscape of DNA methylation and its functions have evolved. Here, we explore the DNA methylation profile of two species of the crustacean Daphnia using whole genome bisulfite sequencing. We then compare our data with the methylomes of two insects and two mammals to achieve a better understanding of the function of DNA methylation in Daphnia...

Insects provide an accessible system to study the contribution of DNA methylation to complex epigenetic phenotypes created to regulate gene expression, chromatin states, imprinting and dosage compensation. The members of genus Drosophila have been used as a model system to study aspects of biology like development, behaviour and genetics. Despite the popularity of Drosophila melanogaster as a genetic and epigenetic model organism, DNA methylation studies are limited due to low levels of genomic 5-methylcytosine...

The anti-inflammatory ibuprofen is a ubiquitous surface water contaminant. However, the chronic impact of this pharmaceutical on aquatic invertebrate populations remains poorly understood. In model insect Aedes aegypti, we investigated the intergenerational consequences of parental chronic exposure to an environmentally relevant concentration of ibuprofen. While exposed individuals did not show any phenotypic changes, their progeny showed accelerated development and an increased tolerance to starvation. In order to understand the mechanistic processes underpinning the direct and intergenerational impacts of ibuprofen, we combined transcriptomic, metabolomics, and hormone kinetics studies at several life stages in exposed individuals and their progeny...

Biochemical, proteomic, and epigenetic studies of chromatin rely on the ability to efficiently isolate native nucleosomes in high yield and purity. However, isolation of native chromatin suitable for many downstream experiments remains a challenging task. This is especially true for the budding yeast Saccharomyces cerevisiae , which continues to serve as an important model organism for the study of chromatin structure and function. Here, we developed a time- and cost-efficient universal protocol for isolation of native chromatin fragments from yeast, insect, and mammalian cells...