-
Advances in Parasitology 2016There are major gaps in our knowledge of many molecular biological processes that take place during the development of parasitic nematodes, in spite of the fact that... (Review)
Review
There are major gaps in our knowledge of many molecular biological processes that take place during the development of parasitic nematodes, in spite of the fact that understanding such processes could lead to new ways of treating and controlling parasitic diseases via the disruption of one or more biological pathways in the parasites. Progress in genomics, transcriptomics, proteomics and bioinformatics now provides unique opportunities to investigate the molecular basis of key developmental processes in parasitic nematodes. The porcine nodule worm, Oesophagostomum dentatum, represents a large order (Strongylida) of socioeconomically important nematodes, and provides a useful platform for exploring molecular developmental processes, particularly given that this nematode can be grown and maintained in culture in vitro for periods longer than most other nematodes of this order. In this article, we focus on the moulting process (ecdysis) in nematodes; review recent advances in our understanding of molecular aspects of moulting in O. dentatum achieved by using integrated proteomic-bioinformatic tools and discuss key implications and future prospects for research in this area, also with respect to developing new anti-nematode interventions and biotechnological outcomes.
Topics: Animals; Models, Animal; Molting; Oesophagostomum
PubMed: 27015950
DOI: 10.1016/bs.apar.2015.09.001 -
BMC Genomics Oct 2015A complete understanding of barnacle adhesion remains elusive as the process occurs within and beneath the confines of a rigid calcified shell. Barnacle cement is mainly...
BACKGROUND
A complete understanding of barnacle adhesion remains elusive as the process occurs within and beneath the confines of a rigid calcified shell. Barnacle cement is mainly proteinaceous and several individual proteins have been identified in the hardened cement at the barnacle-substrate interface. Little is known about the molt- and tissue-specific expression of cement protein genes but could offer valuable insight into the complex multi-step processes of barnacle growth and adhesion.
METHODS
The main body and sub-mantle tissue of the barnacle Amphibalanus amphitrite (basionym Balanus amphitrite) were collected in pre- and post-molt stages. RNA-seq technology was used to analyze the transcriptome for differential gene expression at these two stages and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) was used to analyze the protein content of barnacle secretions.
RESULTS
We report on the transcriptomic analysis of barnacle cement gland tissue in pre- and post-molt growth stages and proteomic investigation of barnacle secretions. While no significant difference was found in the expression of cement proteins genes at pre- and post-molting stages, expression levels were highly elevated in the sub-mantle tissue (where the cement glands are located) compared to the main barnacle body. We report the discovery of a novel 114kD cement protein, which is identified in material secreted onto various surfaces by adult barnacles and with the encoding gene highly expressed in the sub-mantle tissue. Further differential gene expression analysis of the sub-mantle tissue samples reveals a limited number of genes highly expressed in pre-molt samples with a range of functions including cuticular development, biominerialization, and proteolytic activity.
CONCLUSIONS
The expression of cement protein genes appears to remain constant through the molt cycle and is largely confined to the sub-mantle tissue. Our results reveal a novel and potentially prominent protein to the mix of cement-related components in A. amphitrite. Despite the lack of a complete genome, sample collection allowed for extended transcriptomic analysis of pre- and post-molt barnacle samples and identified a number of highly-expressed genes. Our results highlight the complexities of this sessile marine organism as it grows via molt cycles and increases the area over which it exhibits robust adhesion to its substrate.
Topics: Animals; Computational Biology; Gene Expression; Gene Expression Profiling; Gene Expression Regulation; High-Throughput Nucleotide Sequencing; Molecular Sequence Annotation; Molting; Proteins; Thoracica; Transcriptome
PubMed: 26496984
DOI: 10.1186/s12864-015-2076-1 -
Journal of Structural Biology Nov 2020One fundamental character common to pancrustaceans (Crustacea and Hexapoda) is a mineralized rigid exoskeleton whose principal organic components are chitin and...
One fundamental character common to pancrustaceans (Crustacea and Hexapoda) is a mineralized rigid exoskeleton whose principal organic components are chitin and proteins. In contrast to traditional research in the field that has been devoted to the structural and physicochemical aspects of biomineralization, the present study explores transcriptomic aspects of biomineralization as a first step towards adding a complementary molecular layer to this field. The rigidity of the exoskeleton in pancrustaceans dictates essential molt cycles enabling morphological changes and growth. Thus, formation and mineralization of the exoskeleton are concomitant to the timeline of the molt cycle. Skeletal proteinaceous toolkit elements have been discovered in previous studies using innovative molt-related binary gene expression patterns derived from transcriptomic libraries representing the major stages comprising the molt cycle of the decapod crustacean Cherax quadricarinatus. Here, we revisited some prominent exoskeleton-related structural proteins encoding and, using the above molt-related binary pattern methodology, enlarged the transcriptomic database of C. quadricarinatus. The latter was done by establishing a new transcriptomic library of the cuticle forming epithelium and molar tooth at four different molt stages (i.e., inter-molt, early pre-molt, late pre-molt and post-molt) and incorporating it to a previous transcriptome derived from the gastroliths and mandible. The wider multigenic approach facilitated by the newly expanded transcriptomic database not only revisited single genes of the molecular toolkit, but also provided both scattered and specific information that broaden the overview of proteins and gene clusters which are involved in the construction and biomineralization of the exoskeleton in decapod crustaceans.
Topics: Animal Shells; Animals; Biomineralization; Chitin; Crustacea; Epithelium; Gene Expression Profiling; Molar; Molting; Proteins; Transcriptome
PubMed: 32896659
DOI: 10.1016/j.jsb.2020.107612 -
ELife Jul 2019Ecdysis (moulting) is the defining character of Ecdysoza (arthropods, nematodes and related phyla). Despite superficial similarities, the signalling cascade underlying...
Ecdysis (moulting) is the defining character of Ecdysoza (arthropods, nematodes and related phyla). Despite superficial similarities, the signalling cascade underlying moulting differs between Panarthropoda and the remaining ecdysozoans. Here, we reconstruct the evolution of major components of the ecdysis pathway. Its key elements evolved much earlier than previously thought and are present in non-moulting lophotrochozoans and deuterostomes. Eclosion hormone (EH) and bursicon originated prior to the cnidarian-bilaterian split, whereas ecdysis-triggering hormone (ETH) and crustacean cardioactive peptide (CCAP) evolved in the bilaterian last common ancestor (LCA). Identification of EH, CCAP and bursicon in Onychophora and EH, ETH and CCAP in Tardigrada suggests that the pathway was present in the panarthropod LCA. Trunk, an ancient extracellular signalling molecule and a well-established paralog of the insect peptide prothoracicotropic hormone (PTTH), is present in the non-bilaterian ctenophore . This constitutes the first case of a ctenophore signalling peptide with homology to a neuropeptide.
Topics: Animals; Arthropods; Biological Evolution; Molting; Signal Transduction
PubMed: 31266593
DOI: 10.7554/eLife.46113 -
Nature Dec 2022Insect societies are tightly integrated, complex biological systems in which group-level properties arise from the interactions between individuals. However, these...
Insect societies are tightly integrated, complex biological systems in which group-level properties arise from the interactions between individuals. However, these interactions have not been studied systematically and therefore remain incompletely known. Here, using a reverse engineering approach, we reveal that unlike solitary insects, ant pupae extrude a secretion derived from the moulting fluid that is rich in nutrients, hormones and neuroactive substances. This secretion elicits parental care behaviour and is rapidly removed and consumed by the adults. This behaviour is crucial for pupal survival; if the secretion is not removed, pupae develop fungal infections and die. Analogous to mammalian milk, the secretion is also an important source of early larval nutrition, and young larvae exhibit stunted growth and decreased survival without access to the fluid. We show that this derived social function of the moulting fluid generalizes across the ants. This secretion thus forms the basis of a central and hitherto overlooked interaction network in ant societies, and constitutes a rare example of how a conserved developmental process can be co-opted to provide the mechanistic basis of social interactions. These results implicate moulting fluids in having a major role in the evolution of ant eusociality.
Topics: Animals; Ants; Larva; Molting; Pupa; Social Behavior; Body Fluids
PubMed: 36450990
DOI: 10.1038/s41586-022-05480-9 -
Tropical Biomedicine Sep 2021Juvenile hormone is an exclusive hormone found in insects which involves regulating various insect physiology. A total of eight juvenile hormones have been identified in... (Review)
Review
Juvenile hormone is an exclusive hormone found in insects which involves regulating various insect physiology. A total of eight juvenile hormones have been identified in insects which include JH 0, JH I, JH II, JH III, 4-methyl JH I (Iso- JH 0), JHB III, JHSB III, and MF. Corpora allata are the glands responsible for the production and synthesis of these hormones. They are involved in moulting, reproduction, polyethism, and behavioural regulations in different orders of insects. Factors such as diet temperatures, photoperiods, and plant compounds affect the biosynthesis and regulation of juvenile hormones. Juvenile hormones analogue is usually used to disrupt normal regulation of JH and this analogue is categorized as insect-growth regulators (IGRs) and is widely used in pest control as an alternative to chemical insecticides. Other applications of biosynthesis activities of this hormone have not been explored in the area of JHs. In this review, current applications of JHs with an addition of their future application will be discussed.
Topics: Animals; Corpora Allata; Insecta; Juvenile Hormones; Molting; Pest Control
PubMed: 34362868
DOI: 10.47665/tb.38.3.066 -
Biological Reviews of the Cambridge... Aug 2018Animals that occupy temperate and polar regions have specialized traits that help them survive in harsh, highly seasonal environments. One particularly important... (Review)
Review
Animals that occupy temperate and polar regions have specialized traits that help them survive in harsh, highly seasonal environments. One particularly important adaptation is seasonal coat colour (SCC) moulting. Over 20 species of birds and mammals distributed across the northern hemisphere undergo complete, biannual colour change from brown in the summer to completely white in the winter. But as climate change decreases duration of snow cover, seasonally winter white species (including the snowshoe hare Lepus americanus, Arctic fox Vulpes lagopus and willow ptarmigan Lagopus lagopus) become highly contrasted against dark snowless backgrounds. The negative consequences of camouflage mismatch and adaptive potential is of high interest for conservation. Here we provide the first comprehensive review across birds and mammals of the adaptive value and mechanisms underpinning SCC moulting. We found that across species, the main function of SCC moults is seasonal camouflage against snow, and photoperiod is the main driver of the moult phenology. Next, although many underlying mechanisms remain unclear, mammalian species share similarities in some aspects of hair growth, neuroendocrine control, and the effects of intrinsic and extrinsic factors on moult phenology. The underlying basis of SCC moults in birds is less understood and differs from mammals in several aspects. Lastly, our synthesis suggests that due to limited plasticity in SCC moulting, evolutionary adaptation will be necessary to mediate future camouflage mismatch and a detailed understanding of the SCC moulting will be needed to manage populations effectively under climate change.
Topics: Animals; Birds; Climate Change; Mammals; Molting; Pigmentation; Seasons
PubMed: 29504224
DOI: 10.1111/brv.12405 -
Advances in Experimental Medicine and... 2019Chitin, the extracellular matrix polysaccharide of insects and arthropods is widely distributed in nature in all kingdoms of life and serves a variety of functions.... (Review)
Review
Chitin, the extracellular matrix polysaccharide of insects and arthropods is widely distributed in nature in all kingdoms of life and serves a variety of functions. After synthesis by membrane-bound chitin synthases, it is extensively remodeled before incorporation into divergent matrices with wide-ranging physical and biological properties. This chapter discusses the properties of a variety of insect enzymes and proteins involved in this process. Chitin remodeling involves chitin synthases, which make the nascent chitin chains, and chitin deacetylases that partially deacetylate some of the N-acetylglucosamine residues either randomly or sequentially to yield local chitosan-like regions. Other proteins secreted into the procuticle or the midgut help in the assembly of single chitin chains into larger crystalline aggregates that measure in a few 100 nanometers. They are further embedded in a complex matrix of cuticular proteins or become associated with proteins containing chitin-binding domains to constitute the laminar procuticle or the lattice-like peritrophic matrix. During molting, previously formed laminar cuticle or PM are decrystallized/depolymerized to unmask the chitin chains, which then are degraded by a mixture of chitinolytic enzymes consisting of chitinases and N-acetylglucosaminidases present in molting fluid or in gut secretions. Some of the degradation products may be recycled for the synthesis of new matrices. We present a model of chitin synthesis, assembly, and degradation and the roles of these chitin-remodeling enzymes in this overall process.
Topics: Animals; Chitin; Chitinases; Hexosaminidases; Insect Proteins; Insecta; Molting
PubMed: 31102243
DOI: 10.1007/978-981-13-7318-3_5 -
Journal of Morphology Sep 2023Many animals exhibit morphological changes across ontogeny associated with adaptations to their environment. Sea otters (Enhydra lutris) have the densest fur of any...
Many animals exhibit morphological changes across ontogeny associated with adaptations to their environment. Sea otters (Enhydra lutris) have the densest fur of any animal, which is composed of guard hairs, intermediate hairs, and underhairs. Sea otters live in cold water environments, and their fur traps a layer of air to remain properly insulated, due to morphological adaptations that allow the hairs to trap air when submerged. When a sea otter is born, it has a natal pelage which it will eventually molt and replace with a pelt resembling the adult pelage. Past studies have investigated the morphology and hair density of adult sea otter fur, but these characteristics have not been measured for other age classes, including for the natal pelage. This study quantified ontogenetic changes in hair morphology of southern sea otter (E. lutris nereis) pelts. We measured guard hair length and circularity, shape of cuticular scales on guard hairs and underhairs, and overall hair density for sea otter pelts across six age classes: neonate (<1 month), small pup (1-2 months), large pup (3-5 months), juvenile (6 months-1 year), subadult (1-3 years), and adult (4-9 years). Neonate and small pup pelts had significantly longer guard hairs than older age classes. Natal pelage guard hairs were similarly shaped but smaller in diameter than adult guard hairs. Hairs of the natal pelage had similar cuticular scale patterns as adult hairs, indicating the importance of this structure for the function of the fur. Natal pelage had a lower hair density than the pelage of older age classes, with the adult pelage exhibiting the highest hair density. Overall, the morphological differences between natal and adult pelage in sea otters suggest functional differences that may make sea otter pups more vulnerable to heat loss.
Topics: Animals; Otters; Molting; Acclimatization
PubMed: 37585225
DOI: 10.1002/jmor.21624 -
Genes & Genomics May 2019Molting is a critical developmental process for crustaceans, during which the claw muscles undergo periodic atrophy and restoration. But the mechanism underlying this...
BACKGROUND
Molting is a critical developmental process for crustaceans, during which the claw muscles undergo periodic atrophy and restoration. But the mechanism underlying this special muscle reshuffle around ecdysis is not yet thoroughly understood.
OBJECTIVE
To investigate the molecular mechanism underlying the muscle's reshuffle over the molting cycle of Chinese mitten crab Eriocheir sinensis.
METHODS
The Illumina high-throughput sequencing technique were used to sequence the transcriptome of the whole claw muscles from Chinese mitten crab Eriocheir sinensis in three molting stages (inter-molt C stage, pre-molt D and post-molt A-B stage); the de novo assembly, annotation and functional evaluation of the contigs were performed with bioinformatics tools.
RESULTS
Totally 129,149 unigenes, 128,190 CDS, 33,770 SSRs and a large number of SNP sites were obtained, and 3700 and 12,771 differentially expressed genes (DEGs) were identified respectively in A-B and D stage compared with that in C stage. The identified DEGs were enriched to 746 and 1 408 GO terms respectively in A-B and D stage compared with C stage (p ≤ 0.05). KEGG pathway analysis showed that the DEGs were significantly enriched in 14 and 11 pathways in A-B vs C comparison and D vs C comparison (p ≤ 0.05), respectively. These DEGs are involved in several biological processes critical for the animal's growth and development, such as gene expression, protein synthesis, muscle development, new cuticle reconstruction, oxidation-reduction process and glycolytic process.
CONCLUSION
The data generated in this study is the first transcriptomic resource from the muscles of Chinese mitten crab, which would facilitate to characterize key molecular processes underlying crab muscle's growth and development during the molting cycles.
Topics: Animals; Brachyura; China; Computational Biology; Gene Expression Profiling; Molting; Muscle, Skeletal; Transcriptome
PubMed: 30767169
DOI: 10.1007/s13258-019-00787-w