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Fas‐associated death domain protein (FADD) is an apoptotic adapter molecule that recruits caspases and facilitates the formation of death‐inducing signaling complexes in mammals. In lower animals, FADD forms a complex with immune deficiency and death‐related ced‐3/Nedd2‐like caspase to elicit antimicrobial responses. In this study, we characterized the FADD sequence of Tenebrio molitor (TmFADD) using molecular informatics to understand its role in immune surveillance of the host against microorganisms. The 618 bp open reading frame of TmFADD encodes a polypeptide of 204 amino acids. The protein includes two promiscuous domains, the death‐effector domain and the death domain, found at the N‐ and C‐termini, respectively. TmFADD is clustered with the coleopteran FADD sequences in the phylogenetic tree. Homology‐based structural analysis showed an α‐helical model with a QMEAN score of 0.58. The expression of TmFADD mRNA was conspicuous in the larval and early pupal stages. TmFADD mRNA was distributed in the immune tissues of the larva and was found predominately in the gut of the adult. Infection of the host with Candida albicans, Escherichia coli or Staphylococcus aureus increased the expression of TmFADD mRNA, suggesting that these microorganisms trigger the innate immunity of the host. The silencing of TmFADD transcripts resulted in an increased susceptibility of T. molitor larvae to infection with E. coli, but not to infection with C. albicans or S. aureus. Hence, these results indicate that FADD plays a role in the defense of T. molitor and could open avenues for understanding insect immunity. [ABSTRACT FROM AUTHOR]

This study investigates the mosquitocidal potential of crude petroleum ether extract fractions derived from Gloriosa superba against the dengue mosquito vector Aedes aegypti. Chemical profiling through gas chromatography identified four major metabolites, with nonadecane showing the highest peak area percentage (70.34%). A lethal dosage of fraction IV of G. superba (Gs‐F4), at a maximum concentration of 5.0 ppm, exhibited high mortality rates in second (78%), third (71%) and fourth (51%) instars of Ae. aegypti. A sublethal dosage of Gs‐F4 (3.0 ppm) significantly altered the larval midgut enzymes of cytochrome P450, esterases and glutathione S‐transferases. The repellent activity of Gs‐F4 was dosage dependent, with repellency percentages decreasing from 96% to 50% as the exposure time increased from 15 to 210 mins. The impact of Gs‐F4 on aquatic mosquito predators was marginally toxic (<50%) compared with the commercial compound temephos (1.0 ppm), which exhibited a higher toxicity (>50%). In silico toxicity screening using the BeeToxAI server indicated that three of the four compounds in Gs‐F4 were safe or non‐toxic to honeybees, except for α‐gurjunene (6.29 μg/bee). Although G. superba demonstrates effective larvicidal and repellent activity against Ae. aegypti, the non‐target toxicity against mosquito predators necessitates further toxicological screening on beneficial species under field conditions. [ABSTRACT FROM AUTHOR]

Tick‐borne pathogens (TBPs) are an emerging concern to humans and animals in the Republic of Korea, especially within the military zones of Gangwon Province, a mountainous region abundant with wild fauna and ticks. This study aimed to detect six TBPs in military working dogs (MWDs) and ticks in this region using Nested polymerase chain reaction (nested PCR) and sequencing. The targeted pathogens included Anaplasma phagocytophilum, Bartonella henselae, Borrelia spp., Orientia tsutsugamushi, Severe fever with thrombocytopenia syndrome virus (SFTSV) and tick‐borne encephalitis virus (TBEV). A total of 164 serum samples from MWDs were collected at the Korean Army Military working dog training center and 1418 ticks were collected at various training sites between June 2021 and August 2022. Haemaphysalis longicornis was identified as the predominant species (98.3%, n = 1394), followed by Haemaphysalis flava (1.6%, n = 22) and Ixodes nipponensis (0.1%, n = 2). This study detected A. phagocytophilum and Borrelia theileri in 1.4% (1/72) of the tick pools and detected SFTSV in 0.6% (1/164) of MWD serum samples. The MWD found to be infected with SFTS was a German Shepherd, but showed no significant clinical signs, with a normal complete blood count (CBC). In the phylogenetic analysis, three sequences were acquired. One sequence (OR865211) exhibited 100% homology with 16S rRNA of A. phagocytophilum identified from animals and human patients in the Republic of Korea. Another sequence (OR865152) displayed 99.34%–100% sequence similarity with 16S rRNA of B. theileri fragments. The third sequence (OR865115), which belongs to the SFTS B‐1 genotype, showed 94.7% sequence similarity to a strain identified in the Republic of Korea (KY789441). [ABSTRACT FROM AUTHOR]

Edible insects such as the mealworm (Tenebrio molitor) are emerging as an alternative animal protein resource to meet the needs of a growing global population. However, despite the successful mass production of edible insects, research into practical compound feed for edible insect is still insufficient. In this study, mealworms were fed wheat bran, layer chicken feed mash, chicken pellets and cattle pellets for 1 to 36 days, after which their body length was measured. In the groups fed with chicken feed mash, chicken pellets or cattle pellets, the mean body lengths were 2.88, 2.92 and 2.95 cm, respectively, similar to the 2.95 cm of the control T. molitor fed with wheat bran. Individual weight measurements yielded similar results: control, 7.87 g; chicken feed mash, 7.43 g; chicken pellets, 7.60 g; and cattle pellets, 7.63 g. Analysis of livestock feed intake showed that the intake was 290.4 g in control insects, 137.7 g in insects fed chicken feed mash, 220.2 g in insects fed chicken pellets and 230.3 g in insects fed cattle pellets. In the excretion analysis, the excretion of the control insects (161.60 g) was larger than that of the insects fed with chicken feed mash (93.37 g), chicken pellets (93.40 g) or cattle pellets (133.87 g). An analysis of the nutritional content of T. molitor based on nine major nutrients showed no significant differences between the control and the test groups. These results can be used to improve the price competitiveness and quality of T. molitor for commercial development. [ABSTRACT FROM AUTHOR]

Selective herbicides are used to control undesirable vegetation or weeds in fields without harming crops. Herbicide use for weed management can directly impact the densities of insect pests in agricultural communities as a result of insect mortality during and immediately after application. In insects, the glutathione S‐transferase (GST) enzyme is involved in both the detoxification process and the defense of cellular membranes against oxidative damage. In this study, two TmGSTs (TmGST‐iso1 and TmGST‐iso2) were identified and characterized to elucidate the GST family in Tenebrio molitor. Among the developmental stages of T. molitor, eggs had the highest expression levels of TmGST‐iso1. TmGST‐iso2 expression was highest in the pre‐pupal stage. TmGST‐iso1 expression was high in the guts of early and late larvae, whereas TmGST‐iso2 expression was not observed in early larvae. Adults, both male and female, had the highest levels of TmGST‐iso1 mRNA expression in the gut and reproductive organs, and the highest levels of TmGST‐iso2 expression in the reproductive organs. Quantitative polymerase chain reaction was used to investigate the impact of treatment with butachlor on the mRNA expression of TmGST‐iso1 and TmGST‐iso2 in larvae. TmGST‐iso1 expression increased in the butachlor‐treated group after 3 and 24 h, whereas TmGST‐iso2 expression peaked at 24 h after treatment. This study provides vital information about the detoxifying activities of T. molitor. [ABSTRACT FROM AUTHOR]

Innate immunity is the immediate and exclusive defense mechanism in invertebrates. It acts against foreign agents and pathogens. In insects, this defense mechanism involves a combination of humoral and cellular responses, orchestrated by specific recognition receptors and the activation of various signaling pathways. Remarkably, Toll and Toll‐related proteins play a pivotal role in insect immunity by inducing the production of antimicrobial peptides (AMPs) in response to pathogen attacks. Toll receptors, which are type I transmembrane proteins, significantly affect insect development and the innate immune response, primarily via the nuclear factor kappa‐B signaling pathway. The Malpighian tubules of insects play a crucial role in waste elimination, hemostasis maintenance, and immune defense. The Toll signaling pathway in Malpighian tubules is mainly involved in the production of AMPs. This review provides valuable insights into the mechanisms of the Toll signaling pathway and the morphological and physiological attributes of Malpighian tubules. Moreover, it discusses the classification and functionalities of AMPs synthesized in Malpighian tubules in response to pathogens, thereby contributing to our understanding of innate immunity in insects. [ABSTRACT FROM AUTHOR]

In insects, the production of antimicrobial peptides is considered to be the solo arm of the innate immune response. The Toll and immune deficiency pathways are two major signaling pathways that lead to the production of antimicrobial peptides as final effectors. The dynamic functions of Toll/Toll‐like receptors have been thoroughly reviewed in mammals and Drosophila. During the last decade, we have attempted to clarify the immunological roles of different Toll receptor variants and their ligands in Tenebrio molitor. Accordingly, we showed that TmToll‐8, −9, and −10 mRNA transcripts are induced following systemic injections of Gram‐negative, Gram‐positive, and fungal infections. Our data revealed harmonic expression patterns of TmToll‐8, −9, and −10 throughout the developmental stages of healthy individuals and in response to infections in the examined tissues (Malpighian tubules, gut, fat bodies, and hemolymph), illustrating similar evolutionary conversions of different Toll receptor variants in T. molitor. Taken together, our findings highlight the immunological actions of TmToll‐8, −9, and −10 in response to pathogenic insults in T. molitor. [ABSTRACT FROM AUTHOR]

Agricultural intensification has led to significant increases in production, but the overuse of pesticides and associated hazards pose threats to biodiversity and ecological functions. Catalase (CAT), a key antioxidant enzyme, plays a crucial role in alleviating oxidative stress by directly interacting with toxins. In this study, we identified three CAT isoforms in Tenebrio molitor (TmCAT‐iso1, TmCAT‐iso2 and TmCAT‐iso3). These CATs possess a CAT domain, tetramer interface sites and a heme‐binding pocket. We examined the expression of Tm catalases across all developmental stages and in specific tissues using quantitative real time polymerase chain reaction (qRT‐PCR) experiments. Our findings demonstrate that TmCAT‐iso1 and TmCAT‐iso3 exhibit peak expression in young and late larval stages, respectively, whereas TmCAT‐iso2 shows peak expression during the egg and pre‐pupal stages. Tissue distribution analysis revealed the high expression of TmCAT‐iso1 and TmCAT‐iso2 in larval hemocytes, whereas TmCAT‐iso3 is predominantly expressed in larval Malpighian tubules. Furthermore, injection with chlorantraniliprole significantly elevated mRNA expression levels of TmCAT‐iso1, TmCAT‐iso2, and TmCAT‐iso3 in larval groups, compared with control groups. Our study highlights the distinct developmental stages and tissues where TmCATs are expressed. We also elucidated the effects of pesticide application on the expression of each TmCAT, revealing the physiological characteristics of CATs in response to these pesticides, which are dose‐ and time‐dependent in T. molitor. [ABSTRACT FROM AUTHOR]

Crustacean species are among the most valued seafood with socioeconomic and ecological implications in the global fisheries sector. Microbial infections to the farming stock due to continued expansion and aquaculture puts global crustacean production at risk. Understanding and reviewing the complex innate immune system of crustaceans would be pivotal in formulating informed decisions for the control and management of epidemic diseases, thus making the global crustacean aquaculture industry sustainable. Under the purview of innate immunity in crustaceans, pattern recognition receptors (PRRs) represent the sensors capable of discriminating non‐self pathogenic modules and invoking the activation of immune responses. The immunity to infections can be manifested at cellular (via phagocytosis, apoptosis, nodulation and encapsulation) and humoral (effected by prophenoloxidase cascade, lectins, antimicrobial proteins) levels leading to the elimination of pathogens or subversion of the pathogenic implications. In this review, we discuss the participatory role of 12 types of PRRs identified from crustacean species with an exhaustive focus on structural and functional specificities in binding to pathogens and possible execution of the immune activity. Moreover, we have elaborated on the PRRs‐associated or possible signalling cascades (Toll‐NFκB, IMD‐NFκB and JAK‐STAT) in crustacean species that could bridge our understanding of the resistance or susceptibility of the host to varied pathogenic infections thus providing clues to the regulatory mechanisms involved in pathogenesis of infectious diseases and mechanisms of immunity. [ABSTRACT FROM AUTHOR]

Butterflies are expedient biodiversity indicators of a healthy environment. As virtuous pollinators, they provide environmental and economic benefits to the agricultural and natural ecosystem. The global loss of the butterfly community, especially in tropical regions, is causing irreparable damage to the ecological landscape. This decline in population is due to habitat degradation, forest succession, loss of symbiotic relations, economic loss due to flooding, forest development plans, low grassland area, global warming, and reforestation. Moreover, the limited information on the molecular resources of butterflies impedes informed conservation planning. The Threatened Species Initiative (TSI) of Korea has started to utilize the benefits of transcriptome‐guided discovery of molecular resources of a few butterfly species, and a few others are in the pipeline. The cataloging of new genes and genetic markers provides the possibility to promote selective utilization of fitness traits for adaptation of the species to the wild and a newer habitat. In this review, we assessed the versatility of whole‐transcriptome information of the Korean threatened butterfly species, such as the lycaenid Protantigius superans and Spindasis takanosis, the Nymphalid butterfly, Fabriciana nerippe, and the Papilionid species Parnassius bremeri. The schema employed under TSI, including the sequencing and downstream bioinformatics pipeline, could act as a reference for research outside of Korean butterflies. While the molecular resources are available to be exploited, their utilization for conservation is still in its infancy. It is important to synthesize these studies together to catalyze further conservation work applying genomics approaches. [ABSTRACT FROM AUTHOR]

Extracts of botanical origin naturally contain a complex mixture of chemicals considered effective in managing lepidopteran pests. Chemical screening of the ethanolic leaf extracts of two fig tree species, Ficus lyrata and Ficus auriculata, delivered 12 and 15 phyto‐compounds with relatively high peak area percentages in phytol and flavone, respectively. Larvicidal activity against Spodoptera litura yielded higher mortality rates at maximum‐concentration treatment (600 ppm) with Ficus lyrata (91.3%) and Ficus auriculata (98.5%) extracts during the second instar. Sub‐lethal dosages (300 ppm) of both Ficus lyrata and Ficus auriculata extracts impeded the development and reproduction of lepidopteran pests. The enzyme‐inhibition activity of both fig extracts elicited a significant reduction in the major digestive enzymes alkaline phosphatase, acid phosphatase, and lactate dehydrogenase dose‐responsively. Mid‐gut histological screening of Ficus lyrata and Ficus auriculata extracts displayed gut lumen disruptions, shape alterations of columnar cells, and brush‐border membrane damage. Further, the non‐target toxicity of fig extracts against the red worm Eisenia foetida was minimal compared with that of the chemical temephos. Overall, the Ficus extracts proved to be eco‐friendly strategies for managing the polyphagous pest Spodoptera litura and are potentially more sustainable and less harmful to non‐target earthworms. Nonetheless, in silico predictions suggest that the active compounds in fig extracts are predominantly toxic against honeybees (16 compounds) and violate TICE rules (10 compounds). Therefore, the biological actions of fig extracts' individual novel chemistries need to be examined on target and non‐target species to develop better pest management strategies. [ABSTRACT FROM AUTHOR]

Although Toll-like receptors have been widely identified and functionally characterized in mammalian models and Drosophila, the immunological function of these receptors in other insects remains unclear. Here, we explored the relevant innate immune response of Tenebrio molitor (T. molitor) Toll-3 against Gram-negative bacteria, Gram-positive bacteria, and fungal infections. Our findings indicated that TmToll-3 expression was mainly induced by Candida albicans infections in the fat bodies, gut, Malpighian tubules, and hemolymph of young T. molitor larvae. Surprisingly, Escherichia coli systemic infection caused mortality after TmToll-3 knockdown via RNA interference (RNAi) injection, which was not observed in the control group. Further analyses indicated that in the absence of TmToll-3, the final effector of the Toll signaling pathway, antimicrobial peptide (AMP) genes and relevant transcription factors were significantly downregulated after E. coli challenge. Our results indicated that the expression of almost all AMP genes was suppressed in silenced individuals, whereas the expression of relevant genes was positively regulated after fungal injection. Therefore, this study revealed the immunological involvement of TmToll-3 in T. molitor in response to systematic infections. [ABSTRACT FROM AUTHOR]

The antimicrobial roles of Toll-like receptors have been mainly identified in mammalian models and Drosophila. However, its immunological function in other insects has yet to be fully clarified. Here, we determined the innate immune response involvement of TmToll-2 encountering Gram-negative, Gram-positive, and fungal infection. Our data revealed that TmToll-2 expression could be induced by Escherichia coli, Staphylococcus aureus, and Candida albicans infections in the fat bodies, gut, Malpighian tubules, and hemolymph of Tenebrio molitor young larvae. However, TmToll-2 silencing via RNAi technology revealed that sole E. coli systemic infection caused mortality in the double-strand RNA TmToll-2-injected group compared with that in the control group. Further investigation indicated that in the absence of TmToll-2, the final effector of Toll signaling pathway, antimicrobial peptide (AMP) genes and relevant transcription factors were significantly downregulated, mainly E. coli post-insult. We showed that the expression of all AMP genes was suppressed in the main immune organ of insects, namely, fat bodies, in silenced individuals, while the relevant expressions were not affected after fungal infection. Thus, our research revealed the immunological roles of TmToll-2 in different organs of T. molitor in response to pathogenic insults. [ABSTRACT FROM AUTHOR]