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BioRxiv : the Preprint Server For... May 2024The mammalian PAS-domain protein PERIOD (PER) and its orthologue LIN-42 have been proposed to constitute an evolutionary link between two distinct, circadian and...
The mammalian PAS-domain protein PERIOD (PER) and its orthologue LIN-42 have been proposed to constitute an evolutionary link between two distinct, circadian and developmental, timing systems. However, while the function of PER in animal circadian rhythms is well understood molecularly and mechanistically, this is not true for the function of LIN-42 in timing rhythmic development. Here, using targeted deletions, we find that the LIN-42 PAS domains are dispensable for the protein's function in timing molts. Instead, we observe arrhythmic molts upon deletion of a distinct sequence element, conserved with PER. We show that this element mediates stable binding to KIN-20, the CK1δ/ε orthologue. We demonstrate that CK1δ phosphorylates LIN-42 and define two conserved helical motifs, CK1δ-binding domain A (CK1BD-A) and CK1BD-B, that have distinct roles in controlling CK1δ-binding and kinase activity . KIN-20 and the LIN-42 CK1BD are required for proper molting timing . These interactions mirror the central role of a stable circadian PER-CK1 complex in setting a robust ~24-hour period. Hence, our results establish LIN-42/PER - KIN-20/CK1δ/ε as a functionally conserved signaling module of two distinct chronobiological systems.
PubMed: 38766223
DOI: 10.1101/2024.05.09.593322 -
Arthropod Structure & Development Nov 2023Regeneration is widespread across all animal taxa, but patterns of its distribution and key factors determining regeneration capabilities stay enigmatic. A comparative...
Regeneration is widespread across all animal taxa, but patterns of its distribution and key factors determining regeneration capabilities stay enigmatic. A comparative approach could shed light on the problem, but its efficacy is limited by the fact that data is only available on a few species from derived taxa. Pycnogonida are nested basally within the Chelicerata. They can shed and replace their walking legs and have a high regeneration capacity. In this work, we carried careful observation on leg appendotomy and regeneration processes in a sea spider under laboratory settings. The limb structure and in vivo observation reveal autotomy as the most likely appendotomy mechanism. High regeneration capabilities were ascertained: an anatomically normal but small leg appeared in a single molting cycle and the full functionality regained in 2-3 cycles. Wound closure after appendotomy in N. brevirostre primarily relies on hemolymph coagulation, which apparently differs from both xiphosurans and crustaceans. Regeneration is provided by proliferation in the leg cutpiece. Regenerative morphogenesis resembles the normal ontogenetic morphogenesis of a walking leg, but accelerated. Unlike in most arthropods, in N. brevirostre, regeneration does not necessarily correspond to the molting cycle, inferring a plesiomorphic state.
Topics: Animals; Arthropods; Extremities; Morphogenesis; Regeneration
PubMed: 37866256
DOI: 10.1016/j.asd.2023.101310 -
International Journal of Molecular... Jul 2023The relationship between molting and reproduction has received more attention in economically important crustacean decapods. Molting and reproduction are synergistic...
The relationship between molting and reproduction has received more attention in economically important crustacean decapods. Molting and reproduction are synergistic events in , but the molecular regulatory mechanisms behind them are unclear. In the current study, we performed Illumina sequencing for the ovaries of during the molt cycle (pre-molting, Prm; mid-molting, Mm; and post-molting, Pom). A total of 66.57 Gb of transcriptome data were generated through sequencing, resulting in the identification of 105,149 unigenes whose alignment ratio with the reference genome exceeded 87.57%. Differentially expressed genes (DEGs) were annotated through the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases for gene classification and pathway analysis. A total of twenty-six molt-related DEGs were found, and their expression patterns were examined across various molting stages. The KEGG enrichment analysis revealed that the key pathways involved in regulating the molting process of primarily include the mTOR, insect hormone biosynthesis, TGF-beta, and Wnt signaling pathways. Our transcriptomic data suggest that these pathways crosstalk with each other to regulate the synthesis and degradation of ecdysone throughout the molt cycle. The current study has deepened our understanding of the molecular mechanisms of crustacean molting and will serve as a basis for future studies of crustaceans and other molting animals.
Topics: Animals; Female; Palaemonidae; Molting; Ovary; Gene Expression Profiling; Transcriptome; Reproduction
PubMed: 37446235
DOI: 10.3390/ijms241311056 -
Bulletin of Entomological Research Oct 2023Chemosensory proteins (CSPs) were necessary for insect sensory system to perform important processes such as feeding, mating, spawning, and avoiding natural enemies....
Chemosensory proteins (CSPs) were necessary for insect sensory system to perform important processes such as feeding, mating, spawning, and avoiding natural enemies. However, their functions in non-olfactory organs have been poorly studied. To clarify the function of CSPs in the development of (Walker) larvae, two CSP genes, and , were identified from larval integument transcriptome dataset. Both of MsCSP17 and MsCSP18 contained four conserved cysteine sites (C × (6)-C × (18)-C × (2)-C), with a signal peptide at the N-terminal. RT-qPCR analysis showed that and have different expression patterns among different developmental stages and tissues. was highly expressed in 1st-4th instar larvae, and had high expression in adults. Both genes were expressed highly in larval head, thorax, integument and mandible. Moreover, both of and were lowly expressed in larval integuments when larvae molted for 6 h and 9 h from 3rd to 4th instar, but highly at the beginning and end phase during molting. After injection of dsMsCSP17 and dsMsCSP18, the expression levels of two genes decreased significantly, with the body weight of larvae decreased, the mortality increased, and the eclosion rate decreased. It was suggested that and contributed to the development of larvae.
Topics: Animals; Moths; Larva; Insecta; Transcriptome
PubMed: 37674285
DOI: 10.1017/S0007485323000354 -
Journal of Comparative Physiology. B,... Oct 2023Several species of passerines leave their nest with unfinished feather growth, resulting in lower feather insulation and increased thermoregulatory demands compared to...
Several species of passerines leave their nest with unfinished feather growth, resulting in lower feather insulation and increased thermoregulatory demands compared to adults. However, feather insulation is essential for avian species breeding at northern latitudes, where cold conditions or even snowstorms can occur during the breeding season. In altricial arctic species, increased heat loss caused by poor feather insulation during growth could be counter-adaptative as it creates additional energy demands for thermoregulation. Using flow-through respirometry, we compared resting metabolic rate at thermoneutrality (RMRt), summit metabolic rate (M) and heat loss (conductance) in adult and juvenile snow buntings on their summer and winter grounds. In summer, when buntings are in the Arctic, juveniles had a 12% higher RMRt, likely due to unfinished growth, and lost 14% more heat to the environment than adults. This pattern may result from juveniles fledging early to avoid predation at the cost of lower feather insulation. Surprisingly, an opposite pattern was observed at lower latitudes on their wintering grounds. Although they showed no difference in RMRt and M, adults were losing 12% more heat than juveniles. We suggest that this difference is due to poorer insulative property of plumage in adults stemming from energetic and time constraints encountered during their post-breeding molt. High plumage insulation in first-winter juvenile buntings could be adaptive to reduce thermoregulatory demands and maximize survival in the first winter of life, while adults could use behavioral strategies to compensate for their greater rate of heat loss.
PubMed: 37382694
DOI: 10.1007/s00360-023-01502-8 -
Nano Letters May 2024We introduce a Molecular Theory for Compressible Fluids (MOLT-CF) that enables us to compute free energies and other thermodynamic functions for nanoparticle...
We introduce a Molecular Theory for Compressible Fluids (MOLT-CF) that enables us to compute free energies and other thermodynamic functions for nanoparticle superlattices with any solvent content, including the dry limit. Quantitative agreement is observed between MOLT-CF and united-atom molecular dynamics simulations performed to assess the reliability and precision of the theory. Among other predictions, MOLT-CF shows that the amount of solvent within the superlattice decreases approximately linearly with its vapor pressure and that in the late stages of drying, solvent-filled voids form at lattice interstitials. Applied to single-component superlattices, MOLT-CF predicts fcc-to-bcc Bain transitions for decreasing vapor pressure and for increasing ligand length, both in agreement with experimental results. We explore the stability of other single-component phases and show that the C14 Frank-Kasper phase, which has been reported in experiments, is not a global free-energy minimum. Implications for precise assembly and prediction of multicomponent nanoparticle systems are discussed.
PubMed: 38647381
DOI: 10.1021/acs.nanolett.4c00875 -
Advances in Experimental Medicine and... Jun 2024According to the World Health Organization vector-borne diseases account for more than 17% of all infectious diseases, causing more than 700,000 deaths annually. Vectors...
According to the World Health Organization vector-borne diseases account for more than 17% of all infectious diseases, causing more than 700,000 deaths annually. Vectors are organisms that are able to transmit infectious pathogens between humans, or from animals to humans. Many of these vectors are hematophagous insects, which ingest the pathogen from an infected host during a blood meal, and later transmit it into a new host. Malaria, dengue, African trypanosomiasis, yellow fever, leishmaniasis, Chagas disease, and many others are examples of diseases transmitted by insects.Both the diet and the infection with pathogens trigger changes in many metabolic pathways, including lipid metabolism, compared to other insects. Blood contains mostly proteins and is very poor in lipids and carbohydrates. Thus, hematophagous insects attempt to efficiently digest and absorb diet lipids and also rely on a large de novo lipid biosynthesis based on utilization of proteins and carbohydrates as carbon source. Blood meal triggers essential physiological processes as molting, excretion, and oogenesis; therefore, lipid metabolism and utilization of lipid storage should be finely synchronized and regulated regarding that, in order to provide the necessary energy source for these events. Also, pathogens have evolved mechanisms to hijack essential lipids from the insect host by interfering in the biosynthesis, catabolism, and transport of lipids, which pose challenges to reproduction, survival, fitness, and other insect traits.In this chapter, we have tried to collect and highlight the current knowledge and recent discoveries on the metabolism of lipids in insect vectors of diseases related to the hematophagous diet and pathogen infection.
PubMed: 38954247
DOI: 10.1007/5584_2024_811 -
Five new malformed trilobites from Cambrian and Ordovician deposits from the Natural History Museum.PeerJ 2023Injured trilobites present insight into how a completely extinct group of arthropods responded to traumatic experiences, such as failed predation and moulting...
Injured trilobites present insight into how a completely extinct group of arthropods responded to traumatic experiences, such as failed predation and moulting complications. These specimens are therefore important for more thoroughly understanding the Paleozoic predator-prey systems that involved trilobites. To expand the record of injured trilobites, we present new examples of injured and from the Campsite Cliff Shale Member of the Burgess Shale Formation (Cambrian, Miaolingian, Wuliuan), () from the Jince Formation (Cambrian, Miaolingian, Drumian), from the Llanfawr Mudstones Formation (Middle-Late Ordovician, Darriwilian-Sandbian), and from the Meadowtown Formation, (Middle-Late Ordovician, Darriwilian-Sandbian). We consider the possible origins of these malformations and conclude that most injuries reflect failed predation. Within this framework, possible predators are presented, and we uncover a marked shift in the diversity of animals that targeted trilobites in the Ordovician. We also collate other records of injured and and , highlighting that these species are targets for further understanding patterns and records of trilobite injuries.
Topics: Animals; Museums; Fossils; Arthropods; Predatory Behavior; Molting
PubMed: 37904847
DOI: 10.7717/peerj.16326 -
Frontiers in Endocrinology 2023Molting is a pivotal biological process regulated by the ecdysteroid signaling pathway that requires molecular coordination of two transcription factors, Ecdysone...
PURPOSE
Molting is a pivotal biological process regulated by the ecdysteroid signaling pathway that requires molecular coordination of two transcription factors, Ecdysone receptor (EcR) and ultraspiracle (USP) in arthropods. However, the molecular interplay of EcR and Retinoid X receptor (RXR), the crustacean homolog of USP in the ecdysteroid signaling pathway, is not well understood.
METHODS
In this study, we conducted temporal and spatial expression, co-immunoprecipitation (CO-IP), and luciferase reporter assay experiments to investigate the molecular function and interplay of EcR and RXR during the molting process of the Chinese mitten crab, .
RESULTS
The results showed that the expression level of was more stable and significantly higher than during the entire molting process. However, the expression level of fluctuated dynamically and increased sharply at the premolt stage. The CO-IP and luciferase reporter assay results confirmed the molecular interplay of EcR and RXR. The heterodimer complex formed by the two transcription factors significantly induced the transcription of , an essential gene in the ecdysteroid signaling pathway.
CONCLUSIONS
Our study unveiled the diverse molecular function and molecular interplay of EcR and RXR; is possibly a "constitutive-type" gene, and is possibly a vital speed-limiting gene while both and are required to initiate the ecdysteroid signaling cascade, which may be indispensable for molting regulation in The results provide a theoretical basis for the endocrine control of molting in and novel insights into the molecular mechanism of molting mediated by the ecdysteroid signaling pathway in crustaceans.
Topics: Molting; Retinoid X Receptors; Ecdysteroids; Luciferases
PubMed: 37929030
DOI: 10.3389/fendo.2023.1251723 -
BioRxiv : the Preprint Server For... Nov 2023Body size is a fundamental trait that drives multiple evolutionary and ecological patterns. is a fig-associated nematode that is exceptionally large relative to other...
Body size is a fundamental trait that drives multiple evolutionary and ecological patterns. is a fig-associated nematode that is exceptionally large relative to other members of the genus, including . We previously showed that is large primarily due to postembryonic cell size expansion that occurs during the larval-to-adult transition. Here, we describe gene expression patterns in and throughout this developmental period to understand the transcriptional basis of body size change. We performed RNA-seq in both species across the L3, L4, and adult stages. Most genes are differentially expressed across all developmental stages, consistent with 's divergent ecology and morphology. We also used a model comparison approach to identify orthologs with divergent dynamics across this developmental period between the two species. This included genes connected to neurons, behavior, stress response, developmental timing, and small RNA/chromatin regulation. Multiple hypodermal collagens were also observed to harbor divergent developmental dynamics across this period, and genes important for molting and body morphology were also detected. Genes associated with TGF-β signaling revealed idiosyncratic and unexpected transcriptional patterns given their role in body size regulation in . Widespread transcriptional divergence between these species is unexpected and may be a signature of the ecological and morphological divergence of . Alternatively, transcriptional turnover may be the rule in the genus, indicative of widespread developmental system drift among species. This work lays the foundation for future functional genetic studies interrogating the bases of body size evolution in this group.
PubMed: 37961435
DOI: 10.1101/2023.10.30.564729