Leg development in flies versus grasshoppers: differences in dpp expression do not lead to differences in the expression of downstream components of the leg patterning pathway

All insect legs are structurally similar, characterized by five primary segments. However, this final form is achieved in different ways. Primitively, the legs developed as direct outgrowths of the body wall, a condition retained in most insect species. In some groups, including the lineage containing the genus Drosophila, legs develop indirectly from imaginal discs. Our understanding of the molecular mechanisms regulating leg development is based largely on analysis of this derived mode of leg development in the species D. melanogaster. The current model for Drosophila leg development is divided into two phases, embryonic allocation and imaginal disc patterning, which are distinguished by interactions among the genes wingless (wg), decapentaplegic (dpp) and distalless (dll). In the allocation phase, dll is activated by wg but repressed by dpp. During imaginal disc patterning, dpp and wg cooperatively activate dll and also indirectly inhibit the nuclear localization of Extradenticle (Exd), which divide the leg into distal and proximal domains. In the grasshopper Schistocerca americana, the early expression pattern of dpp differs radically from the Drosophila pattern, suggesting that the genetic interactions that allocate the leg differ between the two species. Despite early differences in dpp expression, wg, Dll and Exd are expressed in similar patterns throughout the development of grasshopper and fly legs, suggesting that some aspects of proximodistal (P/D) patterning are evolutionarily conserved. We also detect differences in later dpp expression, which suggests that dpp likely plays a role in limb segmentation in Schistocerca, but not in Drosophila. The divergence in dpp expression is surprising given that all other comparative data on gene expression during insect leg development indicate that the molecular pathways regulating this process are conserved. However, it is consistent with the early divergence in developmental mode between fly and grasshopper limbs.

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The Broad Transcription Factor Links Hormonal Signaling, Gene Expression, and Cellular Morphogenesis Events During Drosophila Imaginal Disc Development

Genetics ◽

10.1534/genetics.120.303717 ◽

2020 ◽

Vol 216 (4) ◽

pp. 1137-1152

Author(s):

Clinton Rice ◽

Stuart J. Macdonald ◽

Xiaochen Wang ◽

Robert E. Ward

Keyword(s):

Transcription Factor ◽

Cell Shape ◽

Imaginal Disc ◽

Molecular Mechanisms ◽

Ecm Remodeling ◽

Functional Studies ◽

Link Type ◽

Leg Development ◽

Puparium Formation ◽

Physical Changes

Imaginal disc morphogenesis during metamorphosis in Drosophila melanogaster provides an excellent model to uncover molecular mechanisms by which hormonal signals effect physical changes during development. The broad (br) Z2 isoform encodes a transcription factor required for disc morphogenesis in response to 20-hydroxyecdysone, yet how it accomplishes this remains largely unknown. Here, we use functional studies of amorphic br5 mutants and a transcriptional target approach to identify processes driven by br and its regulatory targets in leg imaginal discs. br5 mutants fail to properly remodel their basal extracellular matrix (ECM) between 4 and 7 hr after puparium formation. Additionally, br5 mutant discs do not undergo the cell shape changes necessary for leg elongation and fail to elongate normally when exposed to the protease trypsin. RNA-sequencing of wild-type and br5 mutant leg discs identified 717 genes differentially regulated by br, including a large number of genes involved in glycolysis, and genes that encode proteins that interact with the ECM. RNA interference-based functional studies reveal that several of these genes are required for adult leg formation, particularly those involved in remodeling the ECM. Additionally, br Z2 expression is abruptly shut down at the onset of metamorphosis, and expressing it beyond this time results in failure of leg development during the late prepupal and pupal stages. Taken together, our results suggest that br Z2 is required to drive ECM remodeling, change cell shape, and maintain metabolic activity through the midprepupal stage, but must be switched off to allow expression of pupation genes.

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Specification and Patterning of Drosophila Appendages

Journal of Developmental Biology ◽

10.3390/jdb6030017 ◽

2018 ◽

Vol 6 (3) ◽

pp. 17 ◽

Cited By ~ 7

Author(s):

Mireya Ruiz-Losada ◽

David Blom-Dahl ◽

Sergio Córdoba ◽

Carlos Estella

Keyword(s):

Drosophila Melanogaster ◽

Signaling Pathways ◽

Imaginal Disc ◽

Molecular Mechanisms ◽

Fruit Fly ◽

The Body ◽

Developmental Studies ◽

Insect Wing ◽

Environment Exploration ◽

Larva Development

Appendages are external projections of the body that serve the animal for locomotion, feeding, or environment exploration. The appendages of the fruit fly Drosophila melanogaster are derived from the imaginal discs, epithelial sac-like structures specified in the embryo that grow and pattern during larva development. In the last decades, genetic and developmental studies in the fruit fly have provided extensive knowledge regarding the mechanisms that direct the formation of the appendages. Importantly, many of the signaling pathways and patterning genes identified and characterized in Drosophila have similar functions during vertebrate appendage development. In this review, we will summarize the genetic and molecular mechanisms that lead to the specification of appendage primordia in the embryo and their posterior patterning during imaginal disc development. The identification of the regulatory logic underlying appendage specification in Drosophila suggests that the evolutionary origin of the insect wing is, in part, related to the development of ventral appendages.

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Deacetylation of catalytic lysine in CDK1 is essential for Cyclin-B binding and cell cycle

10.1101/420000 ◽

2018 ◽

Author(s):

Shaunak Deota ◽

Sivasudhan Rathnachalam ◽

Kanojia Namrata ◽

Mayank Boob ◽

Amit Fulzele ◽

...

Keyword(s):

Cell Cycle ◽

High Resolution ◽

Cell Cycle Progression ◽

Molecular Mechanisms ◽

Current Model ◽

Cyclin B ◽

Cycle Progression ◽

Cyclin Dependent Kinases ◽

Evolutionarily Conserved ◽

Cycle Dependent

AbstractCyclin-dependent-kinases (CDKs) are essential for cell cycle progression. While dependence of CDK activity on Cyclin levels is established, molecular mechanisms that regulate their binding are less studied. Here, we show that CDKl:Cyclin-B interactions are regulated by acetylation, which was hitherto unknown. We demonstrate that cell cycle dependent acetylation of the evolutionarily conserved catalytic lysine in CDK1 or eliminating its charge state abrogates Cyclin-B binding. Opposing activities of SIRT1 and P300 regulate acetylation, which marks a reserved pool of CDK1. Our high resolution structural analyses into the formation of kinase competent CDK1: Cyclin-B complex have unveiled long-range effects of catalytic lysine in configuring the CDK1 interface for Cyclin-B binding. Cells expressing acetylation mimic mutant of Cdc2 in yeast are arrested in G2 and fail to divide. Thus, by illustrating cell cycle dependent deacetylation as a determinant of CDK1:Cyclin-B interaction, our results redefine the current model of CDK1 activation and cell cycle progression.

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Asexual Reproduction in Holothurians

The Scientific World JOURNAL ◽

10.1155/2014/527234 ◽

2014 ◽

Vol 2014 ◽

pp. 1-13 ◽

Cited By ~ 13

Author(s):

Igor Yu. Dolmatov

Keyword(s):

Asexual Reproduction ◽

Body Wall ◽

Molecular Mechanisms ◽

Basic Mechanism ◽

The Body ◽

Cross Link ◽

Additional Species ◽

Reproduction Mode ◽

History Of ◽

Anterior Posterior

Aspects of asexual reproduction in holothurians are discussed. Holothurians are significant as fishery and aquaculture items and have high commercial value. The last review on holothurian asexual reproduction was published 18 years ago and included only 8 species. An analysis of the available literature shows that asexual reproduction has now been confirmed in 16 holothurian species. Five additional species are also most likely capable of fission. The recent discovery of new fissiparous holothurian species indicates that this reproduction mode is more widespread in Holothuroidea than previously believed. New data about the history of the discovery of asexual reproduction in holothurians, features of fission, and regeneration of anterior and posterior fragments are described here. Asexual reproduction is obviously controlled by the integrated systems of the organism, primarily the nervous system. Special molecular mechanisms appear to determine the location where fission occurs along the anterior-posterior axis of the body. Alteration of the connective tissue strength of the body wall may play an important role during fission of holothurians. The basic mechanism of fission is the interaction of matrix metalloproteinases, their inhibitors, and enzymes forming cross-link complexes between fibrils of collagen. The population dynamics of fissiparous holothurians are discussed.

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TRP Channels in Visceral Pain

The Open Pain Journal ◽

10.2174/1876386301306010023 ◽

2013 ◽

Vol 6 (1) ◽

pp. 23-30 ◽

Cited By ~ 3

Author(s):

L. Ashley Blackshaw ◽

Stuart M. Brierley ◽

Andrea M. Harrington ◽

Patrick A. Hughes

Keyword(s):

Body Wall ◽

Molecular Mechanisms ◽

Trp Channels ◽

Visceral Pain ◽

Low Ph ◽

The Body ◽

Visceral Afferents ◽

Somatic Pain ◽

Oesophageal Mucosa ◽

Chemosensory Function

Visceral pain is both different and similar to somatic pain - different in being poorly localized and usually referred elsewhere to the body wall, but similar in many of the molecular mechanisms it employs (like TRP channels) and the specialization of afferent endings to detect painful stimuli. TRPV1 is sensitive to low pH. pH is lowest in gastric juice, which may cause severe pain when exposed to the oesophageal mucosa, and probably works via TRPV1. TRPV1 is found in afferent fibres throughout the viscera, and the TRPV1 agonist capsaicin can recapitulate symptoms experienced in disease. TRPV1 is also involved in normal mechanosensory function in the gut. Roles for TRPV4 and TRPA1 have also been described in visceral afferents, and TRPV4 is highly enriched in them, where it plays a major role in both mechanonociception and chemonociception. It may provide a visceral-specific nociceptor target for drug development. TRPA1 is also involved in mechano-and chemosensory function, but not as selectively as TRPV4. TRPA1 is colocalized with TRPV1 in visceral afferents, where they influence each other's function. Another modulator of TRPV1 is the cool/mint receptor TRPM8, which, when activated can abrogate responses mediated via TRPV1, suggesting that TRPM8 agonists may provide analgesia via this pathway. In all, the viscera are rich in TRP channel targets on nociceptive neurones which we hope will provide opportunities for therapeutic analgesia.

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Analysis of the gene transcription patterns and DNA methylation characteristics of triploid sea cucumbers (Apostichopus japonicus)

Scientific Reports ◽

10.1038/s41598-021-87278-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lingshu Han ◽

Yi Sun ◽

Yue Cao ◽

Pingping Gao ◽

Zijiao Quan ◽

...

Keyword(s):

Dna Methylation ◽

Body Wall ◽

Molecular Mechanisms ◽

Apostichopus Japonicus ◽

Economic Benefits ◽

Methylation Pattern ◽

The Body ◽

Aquatic Animal ◽

Sea Cucumbers ◽

Differentially Methylated Genes

AbstractBreeding of polyploid aquatic animals is still an important approach and research hotspot for realizing the economic benefits afforded by the improvement of aquatic animal germplasm. To better understand the molecular mechanisms of the growth of triploid sea cucumbers, we performed gene expression and genome-wide comparisons of DNA methylation using the body wall tissue of triploid sea cucumbers using RNA-seq and MethylRAD-seq technologies. We clarified the expression pattern of triploid sea cucumbers and found no dosage effect. DEGs were significantly enriched in the pathways of nucleic acid and protein synthesis, cell growth, cell division, and other pathways. Moreover, we characterized the methylation pattern changes and found 615 differentially methylated genes at CCGG sites and 447 differentially methylated genes at CCWGG sites. Integrative analysis identified 23 genes (such as Guf1, SGT, Col5a1, HAL, HPS1, etc.) that exhibited correlations between promoter methylation and expression. Altered DNA methylation and expression of various genes suggested their roles and potential functional interactions in the growth of triploid sea cucumbers. Our data provide new insights into the epigenetic and transcriptomic alterations of the body wall tissue of triploid sea cucumbers and preliminarily elucidate the molecular mechanism of their growth, which is of great significance for the breeding of fine varieties of sea cucumbers.

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Lymphangiomatosis of the Body Wall: A Report of Two Cases Associated with Chylothorax and Fatal Outcome

Fetal and Pediatric Pathology ◽

10.3109/15513819709168739 ◽

1997 ◽

Vol 17 (4) ◽

pp. 617-624 ◽

Cited By ~ 1

Author(s):

Philippe Moerman ◽

Chris Van Geet ◽

Hugo Devlieger

Keyword(s):

Body Wall ◽

Fatal Outcome ◽

The Body

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Toxicology

10.1093/oso/9780190662677.003.0007 ◽

2017 ◽

Author(s):

Robert Laumbach ◽

Michael Gochfeld

Keyword(s):

Molecular Mechanisms ◽

Molecular Targets ◽

Toxicity Testing ◽

The Body ◽

Toxic Substances ◽

Basic Principles ◽

Practical Applications ◽

Mechanisms Of Toxicity ◽

Body Distribution ◽

Threshold Doses

This chapter describes the basic principles of toxicology and their application to occupational and environmental health. Topics covered include pathways that toxic substances may take from sources in the environment to molecular targets in the cells of the body where toxic effects occur. These pathways include routes of exposure, absorption into the body, distribution to organs and tissues, metabolism, storage, and excretion. The various types of toxicological endpoints are discussed, along with the concepts of dose-response relationships, threshold doses, and the basis of interindividual differences and interspecies differences in response to exposure to toxic substances. The diversity of cellular and molecular mechanisms of toxicity, including enzyme induction and inhibition, oxidative stress, mutagenesis, carcinogenesis, and teratogenesis, are discussed and the chapter concludes with examples of practical applications in clinical evaluation and in toxicity testing.

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A screen for genetic loci required for body-wall muscle development during embryogenesis in Caenorhabditis elegans.

Genetics ◽

10.1093/genetics/137.2.483 ◽

1994 ◽

Vol 137 (2) ◽

pp. 483-498

Author(s):

J Ahnn ◽

A Fire

Keyword(s):

Caenorhabditis Elegans ◽

Myosin Heavy Chain ◽

Muscle Cell ◽

Heavy Chain ◽

Body Wall ◽

Muscle Development ◽

Contractile Function ◽

The Body ◽

Body Wall Muscle ◽

Genetic Loci

Abstract We have used available chromosomal deficiencies to screen for genetic loci whose zygotic expression is required for formation of body-wall muscle cells during embryogenesis in Caenorhabditis elegans. To test for muscle cell differentiation we have assayed for both contractile function and the expression of muscle-specific structural proteins. Monoclonal antibodies directed against two myosin heavy chain isoforms, the products of the unc-54 and myo-3 genes, were used to detect body-wall muscle differentiation. We have screened 77 deficiencies, covering approximately 72% of the genome. Deficiency homozygotes in most cases stain with antibodies to the body-wall muscle myosins and in many cases muscle contractile function is observed. We have identified two regions showing distinct defects in myosin heavy chain gene expression. Embryos homozygous for deficiencies removing the left tip of chromosome V fail to accumulate the myo-3 and unc-54 products, but express antigens characteristic of hypodermal, pharyngeal and neural development. Embryos lacking a large region on chromosome III accumulate the unc-54 product but not the myo-3 product. We conclude that there exist only a small number of loci whose zygotic expression is uniquely required for adoption of a muscle cell fate.

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