Accessory gland as a site for prothoracicotropic hormone controlled ecdysone synthesis in adult male insects

Insect steroid hormones (ecdysteroids) are important for female reproduction in many insect species and are required for the initiation and coordination of vital developmental processes. Ecdysteroids are also important for adult male physiology and behavior, but their exact function and site of synthesis remains unclear, although previous studies suggest that the reproductive system may be their source. We have examined expression profiles of the ecdysteroidogenic Halloween genes, during development and in adults of the flour beetle Tribolium castaneum. Genes required for the biosynthesis of ecdysone (E), the precursor of the molting hormone 20-hydroxyecdysone (20E), are expressed in the tubular accessory glands (TAGs) of adult males. In contrast, expression of the gene encoding the enzyme mediating 20E synthesis was detected in the ovaries of females. Further, Spookiest (Spot), an enzyme presumably required for endowing tissues with competence to produce ecdysteroids, is male specific and predominantly expressed in the TAGs. We also show that prothoracicotropic hormone (PTTH), a regulator of E synthesis during larval development, regulates ecdysteroid levels in the adult stage in Drosophila melanogaster and the gene for its receptor Torso seems to be expressed specifically in the accessory glands of males. The composite results suggest strongly that the accessory glands of adult male insects are the main source of E, but not 20E. The finding of a possible male-specific source of E raises the possibility that E and 20E have sex-specific roles analogous to the vertebrate sex steroids, where males produce primarily testosterone, the precursor of estradiol. Furthermore this study provides the first evidence that PTTH regulates ecdysteroid synthesis in the adult stage and could explain the original finding that some adult insects are a rich source of PTTH

Searching for new biomarkers in ovarian cancer patients: Rationale and design of a retrospective study under the Mermaid III project

Ovarian cancer is a silent killer and, due to late diagnosis, the primary cause of death amongst gynecological cancers, killing approximately 376 women annually in Denmark. The discovery of a specific and sensitive biomarker for ovarian cancer could improve early diagnosis, but also treatment, by predicting which patients will benefit from specific treatment strategies. The Mermaid III project is consisting of 3 parts including “Early detection, screening and long-term survival,” “Biomarkers and/or prognostic markers” and “The infection theory.” The present paper gives an overview of the part regarding biomarkers and/or prognostic markers, with a focus on rationale and design. The study described has 3 major branches: microRNAs, epigenetics and Next Generation Sequencing. Tissue and blood from ovarian cancer patients, already enrolled in the prospective ongoing pelvic mass cohort, will be examined. Relevant microRNAs and DNA methylation patterns will be investigated using array technology. Patient exomes will be fully sequenced, and identified genetic variations will be validated with Next Generation Sequencing. In all cases, data will be correlated with clinical information on the patient, in order to identify possible biomarkers. A thorough investigation of biomarkers in ovarian cancer, including large numbers of different markers, has never been done before. Besides from improving diagnosis and treatment, other outcomes could be markers for screening, knowledge of the molecular aspects of cancer and the discovery of new drugs. Moreover, biomarkers are a prerequisite for the development of precision medicine. This study will attack the ovarian cancer problem from several angles, thereby increasing the chance of successfully contributing to saving lives

AMPK signaling linked to the schizophrenia-associated 1q21.1 deletion is required for neuronal and sleep maintenance.

The human 1q21.1 deletion of ten genes is associated with increased risk of schizophrenia. This deletion involves the β-subunit of the AMP-activated protein kinase (AMPK) complex, a key energy sensor in the cell. Although neurons have a high demand for energy and low capacity to store nutrients, the role of AMPK in neuronal physiology is poorly defined. Here we show that AMPK is important in the nervous system for maintaining neuronal integrity and for stress survival and longevity in Drosophila. To understand the impact of this signaling system on behavior and its potential contribution to the 1q21.1 deletion syndrome, we focused on sleep, an important role of which is proposed to be the reestablishment of neuronal energy levels that are diminished during energy-demanding wakefulness. Sleep disturbances are one of the most common problems affecting individuals with psychiatric disorders. We show that AMPK is required for maintenance of proper sleep architecture and for sleep recovery following sleep deprivation. Neuronal AMPKβ loss specifically leads to sleep fragmentation and causes dysregulation of genes believed to play a role in sleep homeostasis. Our data also suggest that AMPKβ loss may contribute to the increased risk of developing mental disorders and sleep disturbances associated with the human 1q21.1 deletion

Halloween gene expression during development and in adult <i>Tribolium</i>.

<p>The relative mRNA distribution of the Halloween genes during development and in adults was measured by qPCR. Expression was normalized to <i>rpS3</i> mRNA levels. The step in the ecdysteroid biosynthetic pathway catalyzed by each enzyme is shown on the right. Numbers on the x-axis indicate the day of each stage. E; embryo, F; females, O; ovaries, M; males, R; reproductive systems of males, 7dC; 7-dehydrocholesterol, 2,22,25-dE; 2,22,25-trideoxyecdysone (ketodiol), 2,22-dE; 2,22-dideoxyecdysone (ketotriol), 2-dE; 2-deoxyecdysone, 20E; 20-hydroxyecdysone. Note that the Black Box is believed to include multiple uncharacterized reactions converting 7dC to the ketodiol.</p

Adult ecdysteroid levels are regulated by PTTH that may target the accessory glands in <i>Drosophila</i>.

<p>(A) <i>GFP</i> expression driven by a <i>torso-Gal4</i> line in the bi-nucleated secondary cells of a male accessory gland of <i>Drosophila</i>. Inserts are magnifications showing the two nuclei of spherical secondary cells. Green: GFP, Magenta: DAPI. (B-E) Gene expression was analyzed by qPCR in adult <i>Drosophila</i> males overexpressing <i>ptth</i> (<i>da>ptth</i>) and in animals with reduced expression of <i>torso</i> (<i>da>torso-RNAi</i>) or <i>ptth</i> (<i>da>ptth-RNAi</i>). <i>da>+</i> (<i>da></i> crossed to <i>w¹¹¹⁸,</i> genetic background used by VDRC for generating the RNAi lines) was used as a control and expression was normalized to <i>rpL23</i> mRNA levels. (B and C) Ecdysteroid levels estimated as levels of expression of ecdysteroid target genes <i>E74A, E74B</i> and <i>E75B</i>. (D and E) Expression of Halloween genes <i>phm, dib</i> and <i>sad</i>.</p

A model for sex-specific synthesis and action of ecdysteroids in adults.

<p>The ovaries of female <i>Tribolium</i> express <i>spo</i> and the genes for the terminal hydroxylases, including <i>shd</i>, required for synthesis of 20E. Male accessory glands also express a <i>spo</i>-like gene, <i>spot</i>, and the genes for the terminal hydroxylases required for synthesis of E, but not <i>shd</i>. However, s<i>hd</i> expression was detected in the carcass without the reproductive system indicating that E synthesized by the accessory gland might be converted to 20E in peripheral tissues, like during the larval stages. Alternatively, E produced by the accessory gland may be involved in male-specific hormone signaling or be transferred to females during mating. Multiple arrows indicate several steps in the biosynthetic pathway.</p