Creation of Knock-In Alleles of Insulin Receptor Tagged by Fluorescent Proteins mCherry or EYFP in Fruit Fly .

The insulin/insulin-like growth factor-like signaling (IIS) pathway is highly conserved across metazoans and regulates numerous physiological functions, including development, metabolism, fecundity, and lifespan. The insulin receptor (InR), a crucial membrane receptor in the IIS pathway, is known to be ubiquitously expressed in various tissues, albeit at generally low levels, and its subcellular localization remains incompletely characterized. In this study, we employed CRISPR-mediated mutagenesis in the fruit fly to create knock-in alleles of InR tagged with fluorescent proteins (InR::mCherry or InR::EYFP).

Differences in energy source storage in eye stalks between two species of stalk-eyed flies, Sphyracephala detrahens and Cyrtodiopsis dalmanni.

Some diopsid flies have sexually dimorphic eye stalks that are assumed to require considerable nutrition for growth but are advantageous in competition and courtship. According to the handicap theory, the eye span in some dimorphic species serves as a reliable signal of individual quality to an opponent. However, it is not well understood how well eye span represents energy source storage.

Handicap theory is applied to females but not males in relation to mate choice in the stalk-eyed fly Sphyracephala detrahens.

Handicap theory explains that exaggeratedly developed sexual traits become handicaps but serve as honest signals of quality. Because very weak signals are less likely to provide benefits than to simply incur costs, it is interesting to elucidate how sexual traits are generated and developed during evolution. Many stalk-eyed fly species belonging to tribe Diopsini exhibit marked sexual dimorphism in their eye spans, and males with larger eye spans have larger bodies and reproductive capacities, which are more advantageous in terms of contests between males and acceptance for mating by females.

Morphological and Developmental Traits of the Binucleation of Male Accessory Gland Cells in the Benthic Water Bug, Aphelocheirus vittatus (Hemiptera: Aphelochiridae).

The male accessory glands (MAGs) in insects are pair(s) of internal reproductive organs that produce and secrete the plasma component of seminal fluid. In various insects, MAG size is important for male reproductive success because the fluid provides physiologically active substances and/or nutrients to females to control sperm as well as female reproductive behaviors. Although the MAG epithelial cells in most insect species are standard mononucleate cells, those in some insect taxa are binucleate due to incomplete cytokinesis (e.

Binucleation of male accessory gland cells in the common bed bug Cimex lectularius.

The insect male accessory gland (MAG) is an internal reproductive organ responsible for the synthesis and secretion of seminal fluid components, which play a pivotal role in the male reproductive strategy. In many species of insects, the effective ejaculation of the MAG products is essential for male reproduction. For this purpose, the fruit fly Drosophila has evolved binucleation in the MAG cells, which causes high plasticity of the glandular epithelium, leading to an increase in the volume of seminal fluid that is ejaculated.

Binucleation of Accessory Gland Lobe Contributes to Effective Ejection of Seminal Fluid in Drosophila melanogaster.

The adult male accessory gland in insects is an internal reproductive organ analogous to the mammalian prostate, and secretes various components in the seminal fluid. Products of the accessory gland in the fruit fly Drosophila melanogaster are known to control reproductive behaviors in mated females, such as food uptake, oviposition rate, and rejection of re-mating with other males, all of which increase male reproductive capacity. Production of larger amounts of accessory gland products is thus thought to result in higher male reproductive success.

Adult Intestine Aging Model.

The Drosophila adult has an intestine composed of a series of differentiated cells and tissue stem cells, all of which are similar to the mammalian intestinal cells. The aged adult intestine shows apparent characteristics such as multilayering of absorptive cells, misexpression of cell type-specific genes, and hyperproliferation of stem cells. Recent studies have revealed various gene networks responsible for progression of these aged phenotypes.

Nutrient conditions sensed by the reproductive organ during development optimize male fecundity in Drosophila.

Nutrient conditions affect the reproductive potential and lifespan of many organisms through the insulin signaling pathway. Although this is well characterized in female oogenesis, nutrient-dependent regulation of fertility/fecundity in males is not known. Seminal fluid components synthesized in the accessory gland are required for high fecundity in Drosophila males.

Drosophila Peptide Hormones Allatostatin A and Diuretic Hormone 31 Exhibiting Complementary Gradient Distribution in Posterior Midgut Antagonistically Regulate Midgut Senescence and Adult Lifespan.

Enteroendocrine cells (EEs) are evolutionarily conserved gastrointestinal secretory cells that show scattered distribution in the intestinal epithelium. These cells classified into several subtypes based on the hormones they produce in both mammals and insects. In the fruit fly Drosophila, it has been suggested that nearly equal numbers of two subtypes of EEs (Allatostatin A: AstA and Diuretic hormone 31 : Dh31) are alternately produced from the intestinal stem cells in the posterior midgut.

GATAe regulates intestinal stem cell maintenance and differentiation in Drosophila adult midgut.

Adult intestinal tissues, exposed to the external environment, play important roles including barrier and nutrient-absorption functions. These functions are ensured by adequately controlled rapid-cell metabolism. GATA transcription factors play essential roles in the development and maintenance of adult intestinal tissues both in vertebrates and invertebrates.

Isoform-specific functions of Mud/NuMA mediate binucleation of Drosophila male accessory gland cells.

Background: In standard cell division, the cells undergo karyokinesis and then cytokinesis. Some cells, however, such as cardiomyocytes and hepatocytes, can produce binucleate cells by going through mitosis without cytokinesis. This cytokinesis skipping is thought to be due to the inhibition of cytokinesis machinery such as the central spindle or the contractile ring, but the mechanisms regulating it are unclear.

βν integrin inhibits chronic and high level activation of JNK to repress senescence phenotypes in Drosophila adult midgut.

Proper control of adult stem cells including their proliferation and differentiation is crucial in maintaining homeostasis of well-organized tissues/organs throughout an organism's life. The Drosophila adult midgut has intestinal stem cells (ISCs), which have been exploited as a simple model system to investigate mechanisms controlling adult tissue homeostasis. Here, we found that a viable mutant of βν integrin (βint-ν), encoding one of two Drosophila integrin β subunits, showed a short midgut and abnormal multilayered epithelia accompanied by an increase in ISC proliferation and misdifferentiation defects.

Mathematical modelling and experiments for the proliferation and differentiation of Drosophila intestinal stem cells II.

The Drosophila posterior midgut epithelium mainly consists of intestinal stem cells (ISCs); semi-differentiated cells, i.e. enteroblasts (EBs); and two types of fully differentiated cells, i.

The homeodomain protein defective proventriculus is essential for male accessory gland development to enhance fecundity in Drosophila.

The Drosophila male accessory gland has functions similar to those of the mammalian prostate gland and the seminal vesicle, and secretes accessory gland proteins into the seminal fluid. Each of the two lobes of the accessory gland is composed of two types of binucleate cell: about 1,000 main cells and 40 secondary cells. A well-known accessory gland protein, sex peptide, is secreted from the main cells and induces female postmating response to increase progeny production, whereas little is known about physiological significance of the secondary cells.

Cell death and selective adhesion reorganize the dorsoventral boundary for zigzag patterning of Drosophila wing margin hairs.

Animal tissues and organs are comprised of several types of cells, which are often arranged in a well-ordered pattern. The posterior part of the Drosophila wing margin is covered with a double row of long hairs, which are equally and alternately derived from the dorsal and ventral sides of the wing, exhibiting a zigzag pattern in the lateral view. How this geometrically regular pattern is formed has not been fully understood.

Repair responses to abnormalities in morphogen activity gradient.

Establishing and maintaining a morphogen gradient are important in the growth and patterning of developing organs. When a discontinuity in a morphogen signal gradient is created by somatic mutant clones with aberrant intensities of morphogen signals within the Drosophila wing disc, the clones can be removed by apoptosis to restore the morphogen signal gradient. This apoptosis is termed "morphogenetic apoptosis" and has been observed to occur in a cell autonomous or non-cell autonomous manner.

Mathematical modelling and experiments for the proliferation and differentiation of Drosophila intestinal stem cells I.

We study the proliferation and differentiation of stem cells in the Drosophila posterior midgut epithelium, which mainly consists of intestinal stem cells (ISCs); semi-differentiated cells, i.e. enteroblasts (EBs); and two types of fully differentiated cells, i.

RNAi-mediated knockdown showing impaired cell survival in Drosophila wing imaginal disc.

The genetically amenable organism Drosophila melanogaster has been estimated to have 14,076 protein coding genes in the genome, according to the flybase release note R5.13 (http://flybase.bio.

E-cadherin prolongs the moment for interaction between intestinal stem cell and its progenitor cell to ensure Notch signaling in adult Drosophila midgut.

Intestinal stem cells (ISCs) are required for maintenance of the proper cell composition in the adult intestine. To ensure permanent recruitment of newly differentiated cells, the ISC undergoes asymmetric cell division that generates an ISC itself and a progenitor cell. In the Drosophila midgut, cell fate for the absorptive cell is determined by Notch (N) signal in the progenitor cells that receive a ligand Delta (Dl) produced by the ISCs.

Drosophila T-box transcription factor Optomotor-blind prevents pathological folding and local overgrowth in wing epithelium through confining Hh signal.

Aberration of morphogen signaling leads directly to inappropriate cell differentiation and secondarily causes various pathological phenotypes such as abnormal morphogenesis and tumorigenesis. However, mechanisms for linking morphogen signaling and the higher order phenotypes have not been fully elucidated. Here we focus on the Drosophila T-box gene optomotor-blind (omb), a transcriptional target of a long-range morphogen Decapentaplegic (Dpp).

Wing-to-Leg homeosis by spineless causes apoptosis regulated by Fish-lips, a novel leucine-rich repeat transmembrane protein.

Growth, patterning, and apoptosis are mutually interactive during development. For example, cells that select an abnormal fate in a developing field are frequently removed by apoptosis. An important issue in this process that needs to be resolved is the mechanism used by cells to discern their correct fate from an abnormal fate.

Mechanisms for removal of developmentally abnormal cells: cell competition and morphogenetic apoptosis.

Various cell differentiation signals are tightly linked with apoptotic signals. For example, as a result of somatic mutations, cells within a developing field occasionally receive an altered level of morphogenetic signaling that gives rise to an abnormal cell type. However, these developmentally abnormal cells are frequently removed by activating apoptotic signals.

Morphogenetic apoptosis: a mechanism for correcting discontinuities in morphogen gradients.

Smooth gradients of the morphogens Hh, Dpp, and Wg are required for proper development of Drosophila imaginal discs. Here, it is reported that, when a discontinuity is generated between two adjacent cells in the reception of either the Dpp or Wg signal, then cells on either side of the discontinuity boundary undergo apoptosis by activating the c-Jun N-terminal Kinase (JNK) pathway. Furthermore, in the medial region of the wing imaginal disc, the JNK pathway is also activated if cells do not receive the proper levels of Dpp and Hh signals.