The genus Argiope are known to decorate their webs with various patterns. The purpose of these web decorations, referred to as stabilimenta, is still a subject of debate. They are believed to serve either as lures to attract prey insects or as a means of providing protection to the spider by enhancing the web's visibility to deter potential predators. In this study, we observed spider orientation with respect to the direction of the sun in a controlled laboratory environment. To assess the orientation preference of the spider, the frame was repositioned daily by reversing its direction. Over a period of 21 days, the orientation of the spider was meticulously recorded, distinguishing between the illuminated side (open side) and the shaded side (closed side). field emission scanning electron microscopy (FESEM) visualization were used to investigate the microstructural characterization of stabilimenta in both juvenile and adult spiders. Our results represent that the decorative structure of stabilimentum shows diverse microstructural features according to the maturation level of the spider. In addition, it has been confirmed that spiders tend to prefer the open side direction when stabilimentum is present.
Spider silk, which combines strength and lightness, emerges as an ideal candidate for non-woven fabric production. Unlike synthetic polymeric materials, silk are nontoxic and biocompatible and cause no allergic reaction. In particular, the dragline silk produced by the golden orb-web spider, Trichoephila clavata, is renowned for its superior strength and exceptional mechanical properties compared to other spider silks. Non-woven fabrics have found extensive applications in diverse industrial sectors, owing to their advantageous qualities such as breathability, durability, and lightweight characteristics. Natural dragline silk was extracted from the orb-weaving spider and subsequently randomly arranged. Compressing into a sheet-plane form, in addition to inducing the formation of water-resistant, stable β-sheet structures through ethanol vapor treatment or direct treatment, preserved the morphology of the silk fibers. The resulting non-woven sheets were analyzed with an field emission scanning electron microscope (FESEM) to observe their fine structures and mesh size were measured through image analysis.
Transmission electron microscopy was used to examine the microscopic structural features and myofibril organization of cardiac muscle cells in the orb-web spider T. clavata. There are many myofibrils, many mitochondria, a large sarcoplasmic reticulum, and transverse tubules (T-tubules) in the muscle fibers, even if the myofibril striations may not be as noticeable as in skeletal muscles. Because of their consistent striations, sarcomeres are characterized by Z-lines that are 2.0 μm on average in length and do not clearly distinguish between the A- and I-bands. A single T-tubule paired with a terminal cisterna of the sarcoplasmic reticulum constitutes a dyadic junction, which is primarily located at the A-I level of sarcomeres. Cells are joined by intercalated discs, which create several linkages via specialized junctions such as desmosomes, gap junctions, and fascia adherens—all of which are essential for heart function. Our results with transmission electron microscopy (TEM) clearly show that the contraction of the spider's heart muscle is neurogenically controlled, since each fiber is innervated by a motor neuron branch via neuromuscular junctions. These results highlight the neurogenic process controlling spiders' cardiac muscle contractions and advance our knowledge of the peculiar cardiac muscle structure of these animals.
Silk fibroin (SF) from silkworms has special qualities, and these qualities have drawn a lot of interest lately in SF-based hydrogels for a range of biological applications. However, because there is a dearth of naïve silk materials to collect and prepare, research on the SF-based hydrogels isolated from spider silks has been rather limited. Thus, this study compared the microstructural properties of silk fibroin (SF) hydrogel scaffold, which was taken from the cocoon of the insect silkworm Bombyx mori, with those of hydrogel scaffolds derived from two types of woven silk glands in the orb-web spider Trichonephila clavata: the major ampullate gland (MAG) and the tubuliform gland (TG). The SF hydrogel, which is stabilized by connected SF fibers, has a loose top structure, high porosity, and translucency, according to our FESEM investigation. While the TG hydrogel showed greater porosity, ridge-like or wall-like structures, and stable biocapacity generated by physical cross-linking, the MAG hydrogel showed even higher porosity, elongated fibrous structures, and superior mechanical properties. It is anticipated that the unique microstructural properties of MAG and TG hydrogels will be advantageous when choosing customized substrates to support particular cell types for tissue engineering and regenerative medicine applications.
In contrast to conventional silk fibroin, spider silk's potential as a scaffold material for tissue engineering is examined in this work. The remarkable qualities of spider silk are being researched for use in making films for tissue regeneration. In comparison to silk fibroin films, the study's analysis of orb-web spider Trichonephila clavata films highlights their improved cell adhesion and nanofibrous network structure. Tests for solubility substantiate the durability of spider silk films, while in vitro investigations demonstrate low cytotoxicity and enhance cellular viability. The conclusion highlights the exceptional properties of spider silk, which make it a viable option for tissue engineering applications and a step forward for in vitro cell culture and regenerative bioengineering.
본 연구는 장수풍뎅이(Allomyrina dichotoma) 유충을 가수분해한 후 발생한 가수분해물 시료의 항비만 효능에 관한 결과이다. 먼저 3T3-L1 세포에 대한 시료의 독성을 테스트하였다. 시료 F10, P10, P30은 세포에 62.5ug/ml 처리 시 세포 생존율은 ~87.5% 정도로 나타났으며 F30의 경우 세포가 모두 건강하게 성장하는 것을 알 수 있었다. 다음으로 지질합성 관여 단백질인 SREBP-1과 FAS에 대한 발현 억제 실험을 진행하였다. 시료 F10과 F30을 처리 하였을 때 SREBP-1과 FAS의 발현을 가장 잘 억제한다는 것을 알 수 있었다. 3T3-L1 지방세포 분화 과정을 Oil Red O staining 방법으로 염색 후 관찰을 진행하였다. 컨트롤과 비교하여 시료 F10, F30, P10과 P30을 처리한 지방 세포들은 모두 세포 분화 억제가 관찰되었으며 특히, 시료 F10에서 지방세포 분화 억제가 활발히 발생한다는 것을 알 수 있었다. 위 결과를 종합해 보면, 시료 F10과 F30을 혼합하여 사용한다면 반려동물에 대하여 효과 있는 항비만 사료를 개발할 수 있으리라 판단된다.
Wasp venom is rich in bioactive substances, such as proteins, peptides, and small molecules. The venom significantly affects the mammalian cardiovascular, nervous, and immune systems, causing mild to severe symptoms following stings. It exhibits both procoagulant and anticoagulant activities, and significant research has identified its ability to modulate the mammalian coagulation system. Active substances that inhibit clotting were identified and purified through patient case reports and experimental studies. The study reviewed the findings on how wasp venom interacts with platelets and coagulation factors, such as fibrinogen and prothrombin, and demonstrated its dual influence on the coagulation cascade. This highlights the potential of the venom in therapeutic applications, especially as an anticoagulant, as evidenced by the inhibition of coagulation factors and prolonged clotting times after envenomation, suggesting its utility in developing novel anticoagulant therapies. This review focuses on the anticoagulant effects of social wasp venom, which is prevalent in sting incidents, summarizing the research and observations on its therapeutic potential. This emphasizes the significance of further studies to identify and utilize venom components as innovative anticoagulant treatments.
Athalia japonica (Klug, 1815) is a significant insect pest of turnips in Korea. The complete mitochondrial genome of this species isolated in Korea is reported in this study, which is the first attempt to study Korean Athalia species. The circular genome is 15,662 bp in length and consists of 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and an A+T-rich region. Consistent with most members of the genus Athalia, five of the tRNA genes are rearranged from the typical ground pattern of ancestral insect gene order. Phylogenetic analyses inferred from the nucleotide sequences of 25 mitochondrial genomes indicate that the Korean A. japonica is a distinct member of the genus Athalia. This study accumulates mitochondrial genome data of A. japonica from various countries, providing useful information on mitochondrial genetic differences across geographical distances in the East Asian region.
Stoneflies (Plecoptera) are known for being sensitive to water pollution and are used as bioindicators for evaluating water quality. Among them, Nemouridae, especially the genus Nemoura, which are commonly referred to as winter stoneflies, can be found around streams even during the cold winter months. Nemoura geei Wu, 1929, among them, was originally described from Beijing and is widely distributed in Korea, China, Japan, and the Russian Far East. Here, we report the development and characterization of new functional microsatellite markers of N. geei using high-throughput sequencing technology. A total of 80,661 microsatellite loci were identified with a total length of 1,801,591 bp. The average length was 22.34 bp, and microsatellites occupied 0.42% of the entire sequence. The novel 20 microsatellite markers developed in this study can be usefully applied to the population genetics analyses as important genetic resources for understanding the ecological and evolutionary characteristics of a stonefly species at the population level in Korea.
The major innate immune pathways in Asian longhorned ticks, Haemaphysalis longicornis, include Toll, IMD, and JAK/STAT. In the field, H. longicornis can be infected with various pathogens including Severe Fever with Thrombocytopenia Syndrome Virus (SFTS virus), Rickettsia, Babesia and Anaplasma species. One approach to identify whether ticks are infected with pathogens is by examining the expression levels of immune response genes. To evaluate whether upregulation of immune genes from H. longicornis can serve as an indicator for pathogen infection in ticks, we first designed primer sets for Dorsal, STAT, and Relish from the H. longicornis genome. We then conducted quantitative reverse transcription PCR(qRT-PCR) on cDNA of field-collected H. longicornis and identified individuals with high expression levels in immune response genes. Subsequently, we performed digital PCR assays to determine whether selected ticks were infected with SFTS virus. Using this approach, we evaluated correlation between pathogen infection and upregulation of immune response genes in ticks. Although more experiments are needed to draw conclusions, this study suggests immune response gene-based screening methods for pathogen infected ticks from the field.
Lytic polysaccharide monooxygenases (LPMOs) catalyze the oxidative cleavage of glycosidic bonds in crystalline polysaccharides including chitin and cellulose. The recent discovery of LPMO family proteins in many insect species suggests that they presumably play a role in chitin degradation in the cuticle/exoskeleton, tracheae and peritrophic matrix during insect development. Insect LPMOs belong to auxiliary activity family 15 (AA15/LPMO15) and have been classified into at least four groups based on phylogenetic analysis. In this study, we identified and investigated the physiological functions of group I LPMO15 (MaLPMO15-1 and PhLPMO15-1) in two longhorn beetle species, Monochamus alternatus and Psacothea hilaris. In both species, depletion of LPMO15-1 transcripts by RNAi resulted in a lethal pupal-adult molting defect. The insects were unable to shed their old pupal cuticle and died entrapped in their exuviae. Furthermore, TEM analysis revealed a failure of degradation of the chitinous procuticle layer of their old cuticle, retaining intact horizontal laminae and vertical pore canals containing perpendicularly oriented chitin fibers (pore canal fiber, PCF) in their core. These results indicate that MaLPMO15-1 and PhLPMO15-1 are required for turnover of the chitinous old cuticle, which is critical for insect molting.
It is well known that the JNK pathway regulates AMP production against pathogenic infection in both vertebrates and invertebrates. Tenebrio molitor hep (Tmhep) is an homolog of MAP kinase kinase in mammals. Here, we investigate the immunological function of Tmhep in responses in microbial infection using RNA interference technology. The results showed that silencing of Tmhep increased the larval mortality against microbial challenge, as well as reduced AMP production compared to the control group (dsEGFP-treated group). Conclusively, Tmhep plays an critical role in antimicrobial defense in T. molitor larvae.
In insects, the glutathione S-transferase is initiated in both the detoxification process and the protection of cellular membranes against oxidative damage. In this study, we identified the open reading frame (ORF) sequence of GST-iso1 and 2 from Tenebrio molitor (TmGST-iso1 and 2). To investigate the expression patterrns of TmGST-iso1 and 2 in response to herbicide, 0.06, 0.6, and 6 ㎍/㎕ of butachlor (FarmHannong, Seoul, South Korea) was challenged into T. molitor larvae, resulting that the TmGST-iso1 were highly induced at 3 and 24 h-post injection. Whereas, the highest expression of TmGST-iso2 was detected at 24 h after treatment. This study may contribute to basic information about the detoxifying activities of T. molitor.
Pelle, a serine/threonine kinase, is an intracellular component of the Toll pathway and is involved in antimicrobial peptides (AMPs) production due to pathogenic infection. It is known that the Pelle phosphorylates Cactus and activates the NF-κB signaling pathway in Drosophila, but it is not studied in Tenebrio molitor. In this study we investigated the tissue-specific expression patterns of the Pelle following pathogenic infection at 3, 6, 9, 12, and 24 hours. Additionally, larval mortality and AMP expression against microbial injection were investigated in dsPelle-treated T. molitor larvae. Our results may help to understand the antimicrobial function of TmPelle.
Tube, an intracellular protein of the Toll-pathway, forms a complex with Pelle and MyD88, and regulates a signal transduction to activate NF-κB in Drosophila. To understand the antimicrobial function of TmTube, the induction patterns of TmTube were investigated at 3, 6, 9, 12, and 24 h-post injection of pathogens into 10th to 12th instar larvae. In addition, we investigated the effects of TmTube RNAi on larval mortality and tissue specific AMP expression in response to microbial challenge. Our results will provide a basic information to elucidate the immunological function of TmTube
Tumor necrosis factor receptor-associated factor (TRAF) is known to regulate antimicrobial peptides (AMPs) production in mammals. Here, to understand the immunological function of TmTRAF against microbial challenge, the induction patterns of TmTRAF against microbial infection was investigated by qRT-PCR in the whole-body and tissue of young larvae. In addition, the effects of TmTRAF RNAi on larval mortality and expression of 15 AMP genes in response to microbial infection were investigated. Our studies may help to understand the basic role of AMP production.
Recently, it is demonstrate that the invertebrates have a immune memory, called Immune priming (IP). It was partially studied that the IP is mainly regulated by epigenetic modification. Here, to understand the IP on antimicrobial peptides (AMPs) production, we investigated larval mortality and time-dependent expression patterns of AMP genes in T. molitor larvae challenged with E. coli (two-times injection with a one-month interval). Interestingly, the results indicate that the higher and faster expression levels of most AMP genes were detected compared to the non-primed T. molitor larvae. Our results may used to improve the understanding of mechanisms of invertebrate immune memory.
Pellino, a highly conserved E3 ubiquitin ligase, is known to mediate ubiquitination of phosphorylated Interleukin-1 receptor-related kinase (IRAK) homologs in Toll signaling pathway. To understand the immunological function of TmPellino, we screened the knockdown efficiency of TmPellino by injecting TmPellino-specific dsRNA into T. molitor larvae. Subsequently, we investigated the larval mortality and the tissue-specific expression patterns of antimicrobial peptide (AMP) genes against microbial challenges. Interestingly, the results indicate that the expression of many AMP genes was upregulated in the Malpighian tubules of TmPellino-silenced T. molitor larvae. This study may provide basic information to understand how Tmpellino regulates AMPs production in T. molitor.
Chitin and chitosan, abundant biopolymers from shellfish, crustaceans, and fungal hyphae, have diverse applications in food, biomedical, and industrial sectors. Also, insects offer a one of the chitin and chitosan source, yet research into the biological processes of chitin and chitosan within insects remains inadequate. To investigates the safety and benefits of insect-derived chitin and chitosan, we orally administered crab-derived and insect-derived chitin and chitosan to mice and compared RNA expression. NGS derived sequences were obtained and DEG and GO analyses were performed. This study displays a chance to progress the application of edible insects.
참진드기과(Ixodidae) 속하는 개피참진드기(Haemaphysalis flava)는 동남아시아에서 남아시아에 걸쳐 분포 하며, 다양한 질병을 매개하는 것으로 알려져 있다. 특히 중국, 일본, 한국에서 개피참진드기의 주요 매개 질병인 중증열성혈소판감소증후군(SFTS)의 감염 사례가 지속적으로 증가하는 것으로 보고되고 있다. 이 연구는 Illumina HiSeq 4000 시퀀싱을 통해 raw 데이터를 획득하고, Trinity를 기반으로 de novo assembly를 수행하여 unigene을 확보하였다. 이 결과, 총 69,822개의 unigene이 생성되었으며, 이 중 46,175개의 unigene이 PANM-DB에 annotation 되었다. 또한 KOG, GO 및 KEGG 분석을 통해 30,000개, 19,074개, 9,333개의 unigene이 annotation 되었 으며, InterProScan 결과를 통해 protein kinase, zinc finger (C2H2-type), reverse transcriptase, RNA recognition motif domain 등과 같은 세포 조절 메커니즘과 관련된 유전자가 확인되었다. RepeatMasker(v4.0.6)와 MISA(v1.0)를 사 용하여 unigene에서 SSR 마커를 확인한 결과, 총 3,480개의 SSR 마커가 확인되었으며 이 중 trinucleotide 반복이 1,907개, dinucleotide 반복이 1,274개로 확인되었다. 이러한 연구 결과는 H. flava 암컷의 유전자 및 유전자 조절 메커니즘을 이해하는데 기초 자료로서 활용 가능하며, 질병 전파 감수성에 대한 후속 연구에 유용한 정보를 제공 할 것으로 사료된다.