Silencing Multiple Crustacean Hyperglycaemic Hormone-Encoding Genes in the Redclaw Crayfish Induces Faster Molt Rates with Anomalies.

RNA interference (RNAi)-based biotechnology has been previously implemented in decapod crustaceans. Unlike traditional RNAi methodologies that investigate single gene silencing, we employed a multigene silencing approach in decapods based on chimeric double-stranded RNA (dsRNA) molecules coined 'gene blocks'. Two dsRNA constructs, each targeting three genes of the crustacean hyperglycaemic hormone (CHH) superfamily of neuropeptides, were produced: Type II construct targeting Molt-inhibiting hormone 1 (MIH1), MIH-like 1 (MIHL1), and MIHL2 isoforms and Type I construct targeting ion transport peptide (ITP; a putative hybrid of CHH and MIH) and CHH and CHH-like (CHHL) isoforms.

Effects of molting on the expression of ecdysteroid responsive genes in the crustacean molting gland (Y-organ).

Ecdysteroid molting hormones coordinate arthropod growth and development. Binding of 20-hydroxyecdysone (20E) to ecdysteroid receptor EcR/RXR activates a cascade of nuclear receptor transcription factors that mediate tissue responses to hormone. Insect ecdysteroid responsive and Forkhead box class O (FOXO) transcription factor gene sequences were used to extract orthologs from blackback land crab (Gecarcinus lateralis) Y-organ (YO) transcriptome: Gl-Ecdysone Receptor (EcR), Gl-Broad Complex (Br-C), Gl-E74, Gl-Hormone Receptor 3 (HR3), Gl-Hormone Receptor 4 (HR4), Gl-FOXO, and Gl-Fushi tarazu factor-1 (Ftz-f1).

Phylogenetic and transcriptomic characterization of insulin and growth factor receptor tyrosine kinases in crustaceans.

Receptor tyrosine kinases (RTKs) mediate the actions of growth factors in metazoans. In decapod crustaceans, RTKs are implicated in various physiological processes, such molting and growth, limb regeneration, reproduction and sexual differentiation, and innate immunity. RTKs are organized into two main types: insulin receptors (InsRs) and growth factor receptors, which include epidermal growth factor receptor (EGFR), fibroblast growth factor receptor (FGFR), vascular endothelial growth factor receptor (VEGFR), and platelet-derived growth factor receptor (PDGFR).

analysis of crustacean hyperglycemic hormone family G protein-coupled receptor candidates.

Ecdysteroid molting hormone synthesis is directed by a pair of molting glands or Y-organs (YOs), and this synthesis is inhibited by molt-inhibiting hormone (MIH). MIH is a member of the crustacean hyperglycemic hormone (CHH) neuropeptide superfamily, which includes CHH and insect ion transport peptide (ITP). It is hypothesized that the MIH receptor is a Class A (Rhodopsin-like) G protein-coupled receptor (GPCR).

CrusTome: a transcriptome database resource for large-scale analyses across Crustacea.

Transcriptomes from nontraditional model organisms often harbor a wealth of unexplored data. Examining these data sets can lead to clarity and novel insights in traditional systems, as well as to discoveries across a multitude of fields. Despite significant advances in DNA sequencing technologies and in their adoption, access to genomic and transcriptomic resources for nontraditional model organisms remains limited.

Effects of molting on the expression of ecdysteroid biosynthesis genes in the Y-organ of the blackback land crab, Gecarcinus lateralis.

A pair of Y-organs (YOs) synthesize ecdysteroids that initiate and coordinate molting processes in decapod crustaceans. The YO converts cholesterol to secreted products through a biosynthetic pathway involving a Rieske oxygenase encoded by Neverland (Nvd) and cytochrome P450 monooxygenases encoded by Halloween genes Spook (Spo; Cyp307a1), Phantom (Phm; Cyp306a1), Disembodied (Dib; Cyp302a1), and Shadow (Sad; Cyp315a1). NAD kinase (NADK) and 5-aminolevulinic acid synthase (ALAS) support ecdysteroid synthesis in insects.

De novo transcriptome assemblies of red king crab (Paralithodes camtschaticus) and snow crab (Chionoecetes opilio) molting gland and eyestalk ganglia - Temperature effects on expression of molting and growth regulatory genes in adult red king crab.

Red king crab (Paralithodes camtschaticus) and snow crab (Chionoecetes opilio) are deep-sea crustaceans widely distributed in the North Pacific and Northwest Atlantic Oceans. These giant predators have invaded the Barents Sea over the past decades, and climate-driven temperature changes may influence their distribution and abundance in the sub-Arctic region. Molting and growth in crustaceans are strongly affected by temperature, but the underlying molecular mechanisms are little known, particularly in cold-water species.

Signaling Pathways That Regulate the Crustacean Molting Gland.

A pair of Y-organs (YOs) are the molting glands of decapod crustaceans. They synthesize and secrete steroid molting hormones (ecdysteroids) and their activity is controlled by external and internal signals. The YO transitions through four physiological states over the molt cycle, which are mediated by molt-inhibiting hormone (MIH; basal state), mechanistic Target of Rapamycin Complex 1 (mTORC1; activated state), Transforming Growth Factor-β (TGFβ)/Activin (committed state), and ecdysteroid (repressed state) signaling pathways.

Characterization of Shed genes encoding ecdysone 20-monooxygenase (CYP314A1) in the Y-organ of the blackback land crab, Gecarcinus lateralis.

Molting in decapod crustaceans is controlled by ecdysteroid hormones synthesized and secreted by the molting gland, or Y-organ (YO). Halloween genes encode cytochrome P450 enzymes in the ecdysteroid synthetic pathway. The current paradigm is that YOs secrete an inactive precursor (e.

Ecdysis triggering hormone modulates molt behaviour in the redclaw crayfish Cherax quadricarinatus, providing a mechanistic evidence for conserved function in molt regulation across Pancrustacea.

Molting enables growth and development across ecdysozoa. The molting process is strictly controlled by hormones - ecdysteroids. Ecdysteroidogenesis occurs in theprothoracic glands and stimulated by prothoracicotropic hormone in insects, while it ensues in the Y-organ and regulated by the molt inhibiting hormone in crustaceans.

Recommendations for Advancing Genome to Phenome Research in Non-Model Organisms.

The 2020 SICB Society-wide Symposium "Building Bridges from Genome to Phenome: Molecules, Methods and Models" brought together a diverse group of scientists to discuss recent progress in linking phenotype plasticity to changes at the level of the genome, epigenome, and proteome, while exploring the boundaries between variation and speciation. In a follow-up workshop, participants were asked to assess strengths and weaknesses of current approaches, to identify common barriers inhibiting their progress, and to outline the resources needed to overcome those barriers. Discussion groups generally recognized the absence of any overarching theoretical framework underlying current genome to phenome research and, therefore, called for a new emphasis on the development of conceptual models as well as the interdisciplinary collaborations needed to create and test those models.

Hormonal control of the crustacean molting gland: Insights from transcriptomics and proteomics.

Endocrine control of molting in decapod crustaceans involves the eyestalk neurosecretory center (X-organ/sinus gland complex), regenerating limbs, and a pair of Y-organs (YOs), as molting is induced by eyestalk ablation or multiple leg autotomy and suspended in early premolt by limb bud autotomy. Molt-inhibiting hormone (MIH) and crustacean hyperglycemic hormone (CHH), produced in the X-organ/sinus gland complex, inhibit the YO. The YO transitions through four physiological states over the molt cycle: basal in intermolt; activated in early premolt; committed in mid- and late premolt; and repressed in postmolt.

Characterization of G-protein coupled receptors from the blackback land crab Gecarcinus lateralis Y organ transcriptome over the molt cycle.

Background: G-protein coupled receptors (GPCRs) are ancient, ubiquitous, constitute the largest family of transducing cell surface proteins, and are integral to cell communication via an array of ligands/neuropeptides. Molt inhibiting hormone (MIH) is a key neuropeptide that controls growth and reproduction in crustaceans by regulating the molt cycle. It inhibits ecdysone biosynthesis by a pair of endocrine glands (Y-organs; YOs) through binding a yet uncharacterized GPCR, which triggers a signalling cascade, leading to inhibition of the ecdysis sequence.

Proteomic analysis of the crustacean molting gland (Y-organ) over the course of the molt cycle.

Molting in crustaceans is a highly complex physiological process involving regulation by two paired endocrine glands, the X-organ/sinus gland complex (XO/SG) and the Y-organ (YO). The XO/SG complex is responsible for making molt-inhibiting hormone, which negatively regulates synthesis of molting hormones, ecdysteroids, by the YO. In this study, changes in protein abundance in the YO were characterized over the course of a molt cycle induced by multiple leg autotomy in the blackback land crab, Gecarcinus lateralis.

Effects of temperature on survival, moulting, and expression of neuropeptide and mTOR signalling genes in juvenile Dungeness crab ().

Mechanistic target of rapamymcin (mTOR) is a highly conserved protein kinase that controls cellular protein synthesis and energy homeostasis. We hypothesize that mTOR integrates intrinsic signals (moulting hormones) and extrinsic signals (thermal stress) to regulate moulting and growth in decapod crustaceans. The effects of temperature on survival, moulting and mRNA levels of mTOR signalling genes (, , , and ) and neuropeptides ( and ) were quantified in juvenile Crabs at different moult stages (12, 19 or 26 days postmoult) were transferred from ambient temperature (∼15°C) to temperatures between 5 and 30°C for up to 14 days.

Transcriptomic analysis of differentially expressed genes in the molting gland (Y-organ) of the blackback land crab, Gecarcinus lateralis, during molt-cycle stage transitions.

A transcriptome of the Gecarcinus lateralis molting gland (Y-organ or YO) contained 48,590 contiguous sequences (contigs) from intermolt (IM), early premolt (EP), mid premolt (MP), late premolt (LP), and postmolt (PM) stages. The YO is kept in the basal state in IM by molt-inhibiting hormone (MIH)/cyclic nucleotide-dependent signaling. YO activation in EP requires down-regulation of MIH signaling and activation of mechanistic target of rapamycin (mTOR)-dependent protein synthesis.

Transcriptomic analysis of crustacean molting gland (Y-organ) regulation via the mTOR signaling pathway.

The intermolt crustacean Y-organ (YO) maintains a basal state mediated by pulsatile release of molt inhibiting hormone (MIH), a neuropeptide produced in the eyestalk ganglia, inhibiting YO ecdysteroidogenesis. Reduction of MIH results in YO activation and the animal enters premolt. In the crab, Gecarcinus lateralis, molting was induced by eyestalk ablation (ESA).

Elevated expression of neuropeptide signaling genes in the eyestalk ganglia and Y-organ of Gecarcinus lateralis individuals that are refractory to molt induction.

Molting is induced in decapod crustaceans via multiple leg autotomy (MLA) or eyestalk ablation (ESA). MLA removes five or more walking legs, which are regenerated and become functional appendages at ecdysis. ESA eliminates the primary source of molt-inhibiting hormone (MIH) and crustacean hyperglycemic hormone (CHH), which suppress the production of molting hormones (ecdysteroids) from the molting gland or Y-organ (YO).

Genome Sequence of a Marine Spirillum, ATCC 33336, Isolated from Japan.

ATCC 33336 is a motile gammaproteobacterium with bipolar tufted flagella, noted for its low salt tolerance compared to other marine spirilla. This strain was originally isolated from the putrid infusions of near Hiroshima, Japan. This paper presents a draft genome sequence for ATCC 33336.

Draft Genome Sequence of the Salt Water Bacterium ATCC 11336.

ATCC 11336 is an aerobic, bipolar-tufted gammaproteobacterium first isolated in the Long Island Sound in the 1950s. This announcement offers a genome sequence for ATCC 11336, which has a predicted genome size of 3,782,189 bp (49.13% G+C content) containing 3,540 genes and 3,361 coding sequences.

Localization and expression of molt-inhibiting hormone and nitric oxide synthase in the central nervous system of the green shore crab, Carcinus maenas, and the blackback land crab, Gecarcinus lateralis.

In decapod crustaceans, molting is controlled by the pulsatile release of molt-inhibiting hormone (MIH) from neurosecretory cells in the X-organ/sinus gland (XO/SG) complex in the eyestalk ganglia (ESG). A drop in MIH release triggers molting by activating the molting gland or Y-organ (YO). Post-transcriptional mechanisms ultimately control MIH levels in the hemolymph.

Resources and Recommendations for Using Transcriptomics to Address Grand Challenges in Comparative Biology.

High-throughput RNA sequencing (RNA-seq) technology has become an important tool for studying physiological responses of organisms to changes in their environment. De novo assembly of RNA-seq data has allowed researchers to create a comprehensive catalog of genes expressed in a tissue and to quantify their expression without a complete genome sequence. The contributions from the "Tapping the Power of Crustacean Transcriptomics to Address Grand Challenges in Comparative Biology" symposium in this issue show the successes and limitations of using RNA-seq in the study of crustaceans.

Tapping the Power of Crustacean Transcriptomics to Address Grand Challenges in Comparative Biology: An Introduction to the Symposium.

Crustaceans, and decapods in particular (i.e., crabs, shrimp, and lobsters), are a diverse and ecologically and commercially important group of organisms.

A Comparison of Resources for the Annotation of a De Novo Assembled Transcriptome in the Molting Gland (Y-Organ) of the Blackback Land Crab, Gecarcinus lateralis.

Next-generation sequencing technologies are revolutionizing crustacean biology. De novo assembly of RNA sequencing (RNA-seq) data allows researchers to catalog and quantify genes expressed in tissues of a species that lacks a complete genome sequence. RNA-seq has become an important tool for understanding phenotypic plasticity and the responses of organisms to environmental cues.