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Insect Biochemistry and Molecular... Feb 2024Chitin is one of the most prevalent biomaterials in the natural world. The chitin matrix formation and turnover involve several enzymes for chitin synthesis, maturation,...
Chitin is one of the most prevalent biomaterials in the natural world. The chitin matrix formation and turnover involve several enzymes for chitin synthesis, maturation, and degradation. Sequencing of the Drosophila genome more than twenty years ago revealed that insect genomes contain a number of chitinases, but why insects need so many different chitinases was unclear. Here, we focus on insect GH18 family chitinases and discuss their participation in chitin matrix formation and degradation. We describe their variations in terms of temporal and spatial expression patterns, molecular function, and physiological consequences at chitinous cuticles. We further provide insight into the catalytic mechanisms by discussing chitinase protein domain structures, substrate binding, and enzymatic activities with respect to structural analysis of the enzymatic GH18 domain, substrate-binding cleft, and characteristic TIM-barrel structure.
Topics: Animals; Chitinases; Chitin; Phylogeny; Insecta; Genome, Insect; Biology
PubMed: 38184175
DOI: 10.1016/j.ibmb.2024.104071 -
BMC Genomics Jan 2024Macrobrachium nipponense is a freshwater prawn of economic importance in China. Its reproductive molt is crucial for seedling rearing and directly impacts the industry's...
BACKGROUND
Macrobrachium nipponense is a freshwater prawn of economic importance in China. Its reproductive molt is crucial for seedling rearing and directly impacts the industry's economic efficiency. 20-hydroxyecdysone (20E) controls various physiological behaviors in crustaceans, among which is the initiation of molt. Previous studies have shown that 20E plays a vital role in regulating molt and oviposition in M. nipponense. However, research on the molecular mechanisms underlying the reproductive molt and role of 20E in M. nipponense is still limited.
RESULTS
A total of 240.24 Gb of data was obtained from 18 tissue samples by transcriptome sequencing, with > 6 Gb of clean reads per sample. The efficiency of comparison with the reference transcriptome ranged from 87.05 to 92.48%. A total of 2532 differentially expressed genes (DEGs) were identified. Eighty-seven DEGs associated with molt or 20E were screened in the transcriptomes of the different tissues sampled in both the experimental and control groups. The reliability of the RNA sequencing data was confirmed using Quantitative Real-Time PCR. The expression levels of the eight strong candidate genes showed significant variation at the different stages of molt.
CONCLUSION
This study established the first transcriptome library for the different tissues of M. nipponense in response to 20E and demonstrated the dominant role of 20E in the molting process of this species. The discovery of a large number of 20E-regulated strong candidate DEGs further confirms the extensive regulatory role of 20E and provides a foundation for the deeper understanding of its molecular regulatory mechanisms.
Topics: Female; Animals; Transcriptome; Ecdysterone; Palaemonidae; Reproducibility of Results; Gene Expression Profiling
PubMed: 38183039
DOI: 10.1186/s12864-023-09927-9 -
Aquatic Toxicology (Amsterdam,... Feb 2024Oil and gas industries in the Northern Atlantic Ocean have gradually moved closer to the Arctic areas, a process expected to be further facilitated by sea ice withdrawal... (Review)
Review
Oil and gas industries in the Northern Atlantic Ocean have gradually moved closer to the Arctic areas, a process expected to be further facilitated by sea ice withdrawal caused by global warming. Copepods of the genus Calanus hold a key position in these cold-water food webs, providing an important energetic link between primary production and higher trophic levels. Due to their ecological importance, there is a concern about how accidental oil spills and produced water discharges may impact cold-water copepods. In this review, we summarize the current knowledge of the toxicity of petroleum on North Atlantic and Arctic Calanus copepods. We also review how recent development of high-quality transcriptomes from RNA-sequencing of copepods have identified genes regulating key biological processes, like molting, diapause and reproduction in Calanus copepods, to suggest linkages between exposure, molecular mechanisms and effects on higher levels of biological organization. We found that the available ecotoxicity threshold data for these copepods provide valuable information about their sensitivity to acute petrogenic exposures; however, there is still insufficient knowledge regarding underlying mechanisms of toxicity and the potential for long-term implications of relevance for copepod ecology and phenology. Copepod transcriptomics has expanded our understanding of how key biological processes are regulated in cold-water copepods. These advances can improve our understanding of how pollutants affect biological processes, and thus provide the basis for new knowledge frameworks spanning the effect continuum from molecular initiating events to adverse effects of regulatory relevance. Such efforts, guided by concepts such as adverse outcome pathways (AOPs), enable standardized and transparent characterization and evaluation of knowledge and identifies research gaps and priorities. This review suggests enhancing mechanistic understanding of exposure-effect relationships to better understand and link biomarker responses to adverse effects to improve risk assessments assessing ecological effects of pollutant mixtures, like crude oil, in Arctic areas.
Topics: Animals; Copepoda; Water Pollutants, Chemical; Food Chain; Water; Arctic Regions; Petroleum
PubMed: 38176169
DOI: 10.1016/j.aquatox.2023.106825 -
Scientific Reports Jan 2024Ticks are blood-sucking ectoparasites and can transmit various pathogens of medical and veterinary relevance. The life cycle of ticks can be completed under laboratory...
Ticks are blood-sucking ectoparasites and can transmit various pathogens of medical and veterinary relevance. The life cycle of ticks can be completed under laboratory conditions on experimental animals, but the artificial feeding of ticks has attracted increased interest as an alternative method. This study represents the first report on the successful in vitro feeding of all life stages of two-host tick species, Hyalomma scupense and Hyalomma excavatum, and the three-host tick Hyalomma dromedarii. The attachment and engorgement rates of adults were 84% (21/25) and 76% (19/25) for H. scupense females. For adult H. excavatum and H. dromedarii, 70% (21/30) and 34.4% (11/32) of the females attached and all attached females successfully fed to repletion. The oviposition rates of the artificially fed females were 36.4%, 57.1% and 63.1% for H. dromedarii, H. excavatum and H. scupense, respectively, with a reproductive efficiency index varying between 44.3 and 60.7%. For the larvae, the attachment and engorgement rates were 44.2% (313/708) and 42.8% (303/708) for H. dromedarii, 70.5% (129/183) and 56.8% (104/183) for H. excavatum and 92.6% (113/122) and 55.7% (68/122) for H. scupense. The attachment and engorgement rates for the nymphs were 90.2% (129/143) and 47.6% (68/143) for H. dromedarii, 66.7% (34/51) and 41.2% (21/51) for H. excavatum, and 44.1% (30/68) and 36.8% (25/68) for H. scupense. Molting rates of the immature stages varied between 71.3% (216/303) and 100% (68/68) for the larvae and between 61.9% (13/21) and 96% (24/25) for the nymphs. The successful in vitro feeding of all stages of the three Hyalomma species makes this method a valuable tool for tick research, with potential applications in studies on the pathogens transmitted by these tick species such as Theileria annulata.
Topics: Animals; Female; Ticks; Ixodidae; Life Cycle Stages; Nymph; Larva
PubMed: 38172407
DOI: 10.1038/s41598-023-51052-w -
Frontiers in Pharmacology 2023Leukemias are a common cancer in adults and children. While existing treatments are effective, they are associated with severe side-effects compounded by the emergence...
Leukemias are a common cancer in adults and children. While existing treatments are effective, they are associated with severe side-effects compounded by the emergence of drug resistance. This necessitates the need to develop new drugs and phytopharmaceuticals offer a largely untapped source. Oleoresins produced by plants in the genus have been used for centuries in traditional medicine and recent work suggests they may exhibit anti-cancer activity. However, the underlying mechanisms remain unclear and most existing research focusses on ; just one of many species in the genus. To address these limitations, we elucidated the anti-cancer potential and associated mechanisms of action of . A methanolic solvent extraction method was optimised. The effect of methanolic extracts of on leukaemia (K562, MOLT-4 and CCRF-CEM) and normal (PBMC) cell line viability was assessed using MTT assay and flow cytometry. Cell morphology, apoptosis (Annexin-V/propidium iodide), mitochondrial membrane potential (Rhodamine-123) and the cell cycle (propidium iodide) were evaluated using flow cytometry. Regulatory protein expression was quantified using Western Blot. Methanolic extracts of oleoresin reduced the viability of K562, MOLT-4 and CCRF-CEM cell lines with selectivity indexes of between 1.75 and 2.68. Extracts increased the proportion of cells in late apoptosis by 285.4% ± 51.6%. Mitochondrial membrane potential was decreased by 41% ± 2% and the expression of cleaved caspase-3, -7, and -9 was increased by 5.7, 3.3, and 1.5-fold respectively. Extracts increased the proportion of cells in G and G phase by 867.8% ± 122.9% and 14.0 ± 5.5 and decreased those in S phase and G/M by 63.4% ± 2.0% and 57.6% ± 5.3%. Expression of CDK2, CDK6, cyclin D1, and cyclin D3 were decreased by 2.8, 4.9, 3.9, and 2.5-fold. We are the first to report that methanolic extracts of are selectively cytotoxic against three leukemia cell lines. Cytotoxic mechanisms likely include activation of the intrinsic apoptotic pathway and cell cycle arrest through downregulation of CDK2, CDK6, cyclin D1, and cyclin D3. Our findings suggest that may be an important source of novel chemotherapeutic drugs and justifies further investigation.
PubMed: 38155908
DOI: 10.3389/fphar.2023.1282239 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Dec 2023Molting is an important physiological phenomenon of many metamorphosis insects, during which the old and new epidermis are separated by enzymes present in the molting...
Molting is an important physiological phenomenon of many metamorphosis insects, during which the old and new epidermis are separated by enzymes present in the molting fluid. Various proteomic studies have discovered the presence of carboxypeptidase A (Bm-CPA) in the molting fluid of silkworm, but its function remains unclear. In order to better understand the role of Bm-CPA in the molting process of silkworm, Bm-CPA was analyzed by bioinformatics analysis, real-time fluorescence quantitative PCR, antibody preparation, immunofluorescence staining, and expression in . The results showed that Bm-CPA had a conserved M14 zinc carboxypeptidase domain and glycosylation site. Its expression was regulated by ecdysone 20E, and large expression was observed in the epidermis of the upper cluster stage. Immunofluorescence staining showed that Bm-CPA was enriched in the epidermis during the molting stage, and the inhibitor of Bm-CPA led to the larval death due to the inability to molt. We also successfully obtained a large number of recombinant Bm-CPA proteins by expression . These results may facilitate further understanding the molting development process of silkworm.
Topics: Animals; Molting; Bombyx; Carboxypeptidases A; Proteomics; Larva; Fluorescent Antibody Technique; Insect Proteins
PubMed: 38147994
DOI: 10.13345/j.cjb.230246 -
Oecologia Jan 2024Stable isotope analysis provides valuable insights into the ecology of long-distance migratory birds during periods spent away from a specific study site. In a previous...
The association between haemosporidian infection and non-breeding moult location in great reed warblers revisited by combining feather stable isotope profiles and geolocator data.
Stable isotope analysis provides valuable insights into the ecology of long-distance migratory birds during periods spent away from a specific study site. In a previous study, Swedish great reed warblers (Acrocephalus arundinaceus) infected with haemosporidian parasites differed in feather isotope ratios compared to non-infected birds, suggesting that infected and non-infected birds spent the non-breeding season in different locations or habitats. Here, we use a novel dataset comprising geolocator data, isotopes, and haemosporidian infection status of 92 individuals from four Eurasian populations to investigate whether parasite transmission varies with geography or habitats. We found that the probability of harbouring Plasmodium and Leucocytozoon parasites was higher in birds moulting in the eastern region of the non-breeding grounds. However, no geographic pattern occurred for Haemoproteus infections or overall infection status. In contrast to the previous study, we did not find any relationship between feather isotope ratios and overall haemosporidian infection for the entire current dataset. Plasmodium-infected birds had lower feather δN values indicating that they occupied more mesic habitats. Leucocytozoon-infected birds had higher feather δS values suggesting more coastal sites or wetlands with anoxic sulphate reduction. As the composition and prevalence of haemosporidian parasites differed between the old and the current dataset, we suggest that the differences might be a consequence of temporal dynamics of haemosporidian parasites. Our results emphasize the importance of replicating studies conducted on a single population over a restricted time period, as the patterns can become more complex for data from wider geographical areas and different time periods.
Topics: Humans; Animals; Bird Diseases; Feathers; Molting; Plasmodium; Haemosporida; Parasites; Isotopes; Songbirds; Prevalence; Phylogeny
PubMed: 38141067
DOI: 10.1007/s00442-023-05491-x -
Insects Dec 2023Quantitative real-time PCR (qRT-PCR) is widely accepted as a precise and convenient method for quantitatively analyzing the expression of functional genes. The data...
Quantitative real-time PCR (qRT-PCR) is widely accepted as a precise and convenient method for quantitatively analyzing the expression of functional genes. The data normalization strongly depends upon stable reference genes. The bean bug, (Hemiptera: Alydidae), is a significant pest of leguminous crops and broadly distributed across Southeast Asia. In this study, a total of 16 candidate reference genes (, , , , , , -, , , , , , , α-, , and ) were carefully chosen in , and their expression levels were assessed across various conditions, including different developmental stages, diverse tissues, temperature treatments, adult age, molting time, and mating status. Following this, the stability of these reference genes was evaluated using four algorithms (ΔCt, GeNorm, NormFinder, and BestKeeper). Ultimately, the comprehensive rankings were determined using the online tool RefFinder. Our results demonstrate that the reference gene for qRT-PCR analysis in is contingent upon the specific experimental conditions. and are optimal reference genes for developmental stages. Furthermore, α- and exhibit the most stable expression across various adult tissues. and exhibit the most stable expression for adult age. For nymph age, and display the most stable expression. For temperature conditions, and were identified as the most suitable for monitoring gene expression. Lastly, we verified the practicability of evaluating expression levels of odorant-binding protein 37 () and cytochrome P450 6a2 () throughout developmental stages, tissues, and temperature conditions. These findings are a significant addition to the qRT-PCR analysis studies on , serving as a fundamental groundwork for future investigations on stable reference genes in as well as other organisms.
PubMed: 38132633
DOI: 10.3390/insects14120960 -
Proceedings of the National Academy of... Dec 2023To cope with seasonal environmental changes, organisms have evolved approximately 1-y endogenous circannual clocks. These circannual clocks regulate various...
To cope with seasonal environmental changes, organisms have evolved approximately 1-y endogenous circannual clocks. These circannual clocks regulate various physiological properties and behaviors such as reproduction, hibernation, migration, and molting, thus providing organisms with adaptive advantages. Although several hypotheses have been proposed, the genes that regulate circannual rhythms and the underlying mechanisms controlling long-term circannual clocks remain unknown in any organism. Here, we show a transcriptional program underlying the circannual clock in medaka fish (). We monitored the seasonal reproductive rhythms of medaka kept under natural outdoor conditions for 2 y. Linear regression analysis suggested that seasonal changes in reproductive activity were predominantly determined by an endogenous program. Medaka hypothalamic and pituitary transcriptomes were obtained monthly over 2 y and daily on all equinoxes and solstices. Analysis identified 3,341 seasonally oscillating genes and 1,381 daily oscillating genes. We then examined the existence of circannual rhythms in medaka via maintaining them under constant photoperiodic conditions. Medaka exhibited approximately 6-mo free-running circannual rhythms under constant conditions, and monthly transcriptomes under constant conditions identified 518 circannual genes. Gene ontology analysis of circannual genes highlighted the enrichment of genes related to cell proliferation and differentiation. Altogether, our findings support the "histogenesis hypothesis" that postulates the involvement of tissue remodeling in circannual time-keeping.
Topics: Animals; Oryzias; Seasons; Circadian Rhythm; Gonads; Photoperiod
PubMed: 38109538
DOI: 10.1073/pnas.2313514120 -
PeerJ 2023The accurate interpretation of trilobite moulting behaviour relies on a comprehensive understanding of their moult configurations, yet the focus has commonly been...
The accurate interpretation of trilobite moulting behaviour relies on a comprehensive understanding of their moult configurations, yet the focus has commonly been limited to a brief description of the exuviae, and how differences in moulting behaviour further impact the preservation of exuviae is often ignored. This study investigates the configuration, style, and process of moulting in through analysis of 88 exuviae collected from the Kaili Formation (Cambrian, Wuliuan) in Guizhou Province, South China. The moult configurations of are typically characterised by the lower cephalic unit (LCU), which comprises the librigenae and rostral-hypostomal plate connected as a whole, detached from the cephalon and positioned anterior to the thoracopygon, while the cranidium is mostly absent. From detailed observation and description of the available material, we believe that completes its moult through an exuvial gape formed by disarticulation of the facial sutures, rostral sutures and/or sutures of the cephalothoracic joints. Although many exuviae exhibited an opening at the cephalothoracic joint-disjunction of which is usually accompanied by disarticulation of both the facial and rostral sutures-the Salter's configuration produced by the 'Salterian' mode of moulting was not observed. Additionally, the structural characteristics of Henningsmoen's configuration, Harrington's configuration, and Somersault's configuration are discussed based on the exuviae of , and Henningsmoen's configuration has been categorised into three types according to the different states of fossil preservation. In this article, apart from promoting further research on moulting behaviour in , we also provide a supplement for moult configuration based on the exuviae, which offers new materials for studying moulting behaviour in oryctocephalid trilobites.
Topics: Molting; Sutures; Fossils; China; Dietary Supplements
PubMed: 38107583
DOI: 10.7717/peerj.16440