• Journal of fish pathology
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• v.21 no.1
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• pp.45-56
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• 2008

This study was conducted to find out biological responses of bivalves exposed to organotin compound.The results of the study confirmed that tribultyltin chloride (TBTCl) induce reduction of survival rate andburrowing activity, and histopathological feature in the foot structure of the equilateral venus, Gomphinaveneriformis. The experimental period was 36 weeks. The experimental groups consisted of a control and 3TBTCl exposure groups (0.4, 0.6, 0.8 ym TBTCl L'). The survival rate and burrowing activity were record-ed daily. For histological analysis, foot tissues were fixed in Bouin' s fluid and then stained H-E stain, AB-PAS (PH 2.5) reaction and Masson's trichrome stain after having serially sectioned the tissue by paraffinmethod at thickness of 4-6 ym. The survival rate was not significantly different between the control andexposure groups for 20 weeks, but in 0.8 Um TBTCl L', it was on the decreased ever since the exposure. Theburrowing activity was not significantly different in the exposure group compared to the control up to 12weeks, but in 0.6 and 0.8 ym TBTCl L', it measured the lowest level after 20 weeks. The foot is composedof the epidermal layer, connective tissue, and muscular layer. The epidermal layer is composed of simplecolumnar, cuboidal epithelia and mucous cells. The cilia were well developed on the apical surface ofepithelium, Circular, longitudinal and transverse muscle bundle were well developed in the muscular layer.The majority mucous cells showed blue color (542c) when it subjected to AB-PAS (PH 2.5) reaction. Nohistopathological alterations in the foot were observed up to 12 weeks. After 20 weeks of exposure to 0.8 (anTBTCl L'', the foot samples of exposed G. veneriformis showed disappearance of cilia and striated borderpartially and extension of hemolymph sinus. The mucous cell increased in the marginal of foot. At 28-weekof exposure to 0.4 ym TBTCl L', it observed weekly acid (564c), neutral (264c) and mixed mucous cell. At36-week of exposure to 0.6 ym TBTCl L', it showed fragmentation of the muscle and collagen fiber bundle,and also diappearance of cilia on epithelia and edema of epithelium in 0.8 ym TBTCl L''.

• Journal of Sericultural and Entomological Science
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• v.29 no.1
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• pp.20-30
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• 1987

In the hemolymph proteins of the silkworm reared with mulberry leaves and artificial diet, electrophoretic patterns of Storege Protein 1 (SP1) and Vitellogenin(VG), changes of relative concentration of SP1, JHA effects during the developmental stages, and estimation of the molecular weight of vitellin subunits were investigated in the present study. 1. Storage Protein 1 (SP1) showed female specificity from the middle stage of the fifth instar to the end of spinning stage in the silkworm reared with mulberry leaves and artificial diet. 2. Vitellogenin (VG) showed female specififcity just afrter pupation in the silkworm reared with mulberry leaves and artificial diet. 3. Storage Protein 2 (SP2) without female specificity was detected from the early stage of the fifth instar to the first or second day after pupation. 4. Vitellin was composed of two non-identical subunits (vitellin-heavy chain ; VTL-H, vitellinlight chain ; VTL-L) with mplecular weight of 186,000 and 41,000. Also, there were no differenes between the molecular weights of vitellin subunits obtained from silkworms reared with mulberry leaves and artificial diet. 5. Relative concentration of Storage Protein 1 (SP1) after topical application - 0.5, and 10$\mu\textrm{g}$ per body weight - JHA on the 60th hour of the fifth instar showed the highest increase with the treatment of 5$\mu\textrm{g}$ and a higher increase with the treatment of 10$\mu\textrm{g}$ compared with the control (no topical application of JHA).

• Journal of Life Science
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• v.25 no.6
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• pp.715-723
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• 2015

Insects represent the largest class within the animal kingdom in terms of species number. Humans had been utilized insect in the broad area, including food, agriculture, industry, pharmaceuticals and so on. At present, insects are emerging as a leading group for identifying and extracting novel bioactive substances due to enormous number and a high nutritional value. Insects rely on a suite of systemic response to resist infection such as immune cells, hemocytes, activation of enzymes cascades, and antimicrobial peptide/protein. Among the substances, antimicrobial peptides (AMPs) are main components of potent antimircrobial innate defense system into the insect hemolymph. AMPs raise influential candidate as avenue to resolve the development of antibiotic-resistant microbial organism. Insect AMPs are classified into four main classes: cecropins, insect defensins, glycine/proline-rich peptides. Insect AMPs have been purified, over 150. In this review, AMPs derived from several insects were summarized including honey bee, dung beetle, butterfly and longicorn beetle. These peptides almost exhibited potent antimicrobial activities against human microbial pathogens without causing remarkable hemolysis to erythrocytes excluding melittin, and their mode of action(s) are based on disruption of the plasma membrane or fungal apoptosis. Therefore, study of insect AMPs is expected to be useful for designing novel therapeutic antimicrobial applications.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.359-367
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• 2015

Physiological plasticity of insects can be closely related with their epigenetic change. This hypothesis was tested using a polyphagous lepidopteran insect, Spodoptera exigua, by assessing the effects of different diets on development and DNA methylation. Three different diets (Welsh onion (WO), Chinese cabbage (CC), artificial diet (AD)) were assessed by feeding a cohort of larvae from neonate to last instar. There were significant differences in larval developmental rate, pupal weight and adult emergence according to diet treatments. AD-fed larvae exhibited the fastest developmental rate along with the highest pupal weight and adult emergence. Among natural hosts, WO was more favorable for development of S. exigua than CC. Total hemolymph proteins and sugars in the last instar larvae were varied among different diets. Gene expression of an insulin-like peptide (SeILP1) presumably associated with development was also varied among diets. Cytosine methylation of genomic DNA was assessed using a monoclonal antibody. Genomic DNA of S. exigua larvae was methylated. DNA methylation was apparently varied among different diet-fed larvae. The facts that a cohort of S. exigua was differentiated in developmental rate and cytosine methylation by different diets suggest that epigenetic factor(s) may play a crucial role in the physiological plasticity.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.49-57
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• 2014

Orb-web spiders can be considered as an effective bio-indicative animal to monitor the ecological air pollution of certain habitat since they have limited shifting ability during their life spans. In this study we revealed the fine structural characteristics of booklung in the orb-web spider Nephila clavata, and its bio-indicative significance in the monitoring environmental asbestos exposure. The high resolution scanning electron microscopy results suggest that the cuticular spikes near the atrium could be act as an effective filtering structure for dust materials. Furthermore, inner cuticular spikes which protruded across the air sacs, have the functions not only sustaining appropriate respiratory volume of each air sac but also help to enhance respiratory capacity by maximizing the gross surface area for gas exchange. Interestingly, in spite of short exposure, the asbestose fibrils were effectively captured on the surface of the atrial cuticular spikes. Furthermore, histologic damages were observed due to penetration of asbestos fibrils through air sacs and fixed on the hemolymph space. In addition, although accumulated mass of hemocytes were observed near the fibrils, there were no asbestos bodies or coagulated hemocytes were found on the surface of the fibrils, This could be mainly due to the short exposure period towards asbestos. Briefly, these results indicate the spider's booklung could be valuable tool in the detection ecological air pollutants.

• Journal of Sericultural and Entomological Science
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• v.49 no.2
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• pp.37-42
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• 2007

Lactoferrin, an ion-binding 80-kDa glycoprotein, has been suggested to have many biologic activities, such as facilitating ion absorption and having antimicrobial and anti-inflammatory effects. Several of these activities are likely to only be facilitated by human lactoferrin because they depend on the binding of human lactoferrin to specific receptor. To produce recombinant human lactoferrin to animal foods using transgenic silkworm, Bombyx mori L, we have cloned and sequenced the cDNA encoding for a human lactoferrin (HLf) from the mRNA in mammary tumor line (GI-101). As a result, the 2.5-kb fragment of HLf gene was cloned with pGEM-T vector and then this fragment was sequenced. In the nucleotide sequence analysis, single open reading frame of the 2,136-bp encoding for a polypeptide of 712 amino acid residues was detected. On the other hand, we constructed a recombinant plasmid(pPT-HLf), containing human lactoferrin gene for germ line transformation of the silkworm using a piggyBac transposon-derived vector. A nonautonomous helper plasmid encodes the piggyBac transposase. Approximately 6.7% of individuals in the G0 silkworms expressed green fluorescent protein (GFP). PCR analyses of GFP-positive silkworms (G0 and G1) revealed that independent insertions occurred frequently. Furthermore, Western blot analysis showed that the recombinant HLf expressed in hemolymph has the same molecular weight (80 kDa) as a native protein. On the basis of these experiments, expression of HLf in next generation of transgenic silkworm is now in process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.199-203
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• 2016

Apolipophorin-III (apoLp-III) was isolated and purified from the last larval hemolymph of Galleria mellonella by KBr gradient ultracentrifugation and gel chromatography (Sephadex G-100). After KBr gradient ultracentrifugation, the lipophorin-free fractions were used as the samples for gel chromatography. The purity of the finally purified apoLp-III was confirmed by SDS-PAGE after gel chromatography. In this study, we found that apoLp-III is taken up into the adult testes in Galleria mellonella. The testes were dissected from day-1 or -2 adults in cold Ringer's solution and used for tissue culture. The protein moiety of apoLp-III was labeled with FITC dissolved in dimethyl sulfoxide (DMSO) at room temperature under conditions of continuous stirring for 1 h. The FITC-labeled apoLp-III was purified with a Sephadex G-25 PD-10 column. The tissues of the adult testes were incubated at room temperature for 30 min with fluorescein isothiocyanate (FITC)-labeled apoLp-III. Fluorescein microscopy and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) revealed that the adult testis tissues internalize the FITC-labeled apoLp-III. The results showed that apoLp-III is taken up by the adult testes.

• Journal of Sericultural and Entomological Science
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• v.43 no.2
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• pp.59-66
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• 2001

This study was conducted to elucidate phylogenetic relationships and genetic characterization of silkworms that might be recognized as the Korean native strains. Genetic characterization in isozymes and the proteins of larval hemolymph of 17 silkworms were observed by acrylamide gel eletrophoresis, on 12 genes; Bph, Bes, les, Amy-hc, Ict-A, -B, -D,-E,-H, Pfl, Pst, Lp. Gene frequencies in each locus were compared other geographic strains. Korean native strains were remarkably different from others considered as the genetic characterization of Korean native strains. Phylogenetic relationships in Korean native strains were analysed using RAPD-PCR markers. A total of 40 primers were used and 346 bands of amplified DNA were generated from geographic strains. Genetic similarity based on the RAPD bands was used to construct phylogenetic dendrogram based on analysis of bard sharing data of amplified markers. Genetic similarity ranged from 0.595 to 0.860. In the genetic relationship based on dendrogram, they were classified into Bombyx mori group (including 16 domesticated silkworm strains) and B. mandarina group. The Bombyx mori group was separated into three sub-groups at the genetic similarity of 0.6930, including Korean, Japanese and Chinese groups. According to this result, the Korean native variety can be considered as a clearly different variety from other geographic strains. It may be concluded that the Korean native strains are also one of original geographic variety such as Japanese, Chinese, etc.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.377-384
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• 2018

This study focused on the effects of feeding on postlarvae of shrimp, Litopenaeus vannamei, during the identified acclimation time to low salinity. A total of 5 different salinity groups with or without feeding (32, 24, 16, 8, and 2 psu, 1 liter, triplicates) were prepared, and 30 shrimp were settled at PL21 (postlarvae) and placed in each group. After 24 hours of the experimentation process, the survival rate of the fed and starved groups was observed to be lower in the 2 psu group compared to other salinity groups, with the rate of 86.6% and 81.1%, respectively. The condition index of glucose and triglyceride, which are important factors for osmoregulation and as energy sources, was 4.2-7.6 times and 2.7-3.4 times higher in the fed groups than the starved groups at all the levels of salinities. The creatine level increased by 1.1-1.5 times in the starved groups as compared to the fed groups. Likewise, the activity of all the digestive enzymes like, lipase, ${\alpha}$-amylase, trypsin, and alkaline protease were clearly higher in the fed groups (ANOVA, p<0.05). Apparently, it was observed that feeding is effective for the postlarvae of shrimp, which shows a characteristic fast metabolism and larval development, during the acclimation period to low salinity.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.109-115
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• 2022

Vitellogenesis is the process by which yolk accumulates in developing oocytes. The initiation of vitellogenesis represents an important control point in oogenesis. When females of the model insect Drosophila melanogaster molt to become adults, their ovaries lack mature vitellogenic oocytes, only producing them after reproductive maturation. After maturation, vitellogenesis stops until a mating signal re-activates it. Juvenile hormone (JH) from the endocrine organ known as the corpora allata (CA) is the major insect gonadotropin that stimulates vitellogenesis, and the seminal protein sex peptide (SP) has long been implicated as a mating signal that stimulates JH biosynthesis. In this review, we discuss our new findings that explain how the nervous system gates JH biosynthesis and vitellogenesis associated with reproductive maturation and the SP-induced post-mating response. Mated females exhibit diurnal rhythmicity in oogenesis. A subset of brain circadian pacemaker neurons produce Allatostatin C (AstC) to generate a circadian oogenesis rhythm by indirectly regulating JH and vitellogenesis through the brain insulin-producing cells. We also discuss genetic evidence that supports this model and future research directions.