• The Korean Journal of Zoology
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• v.22 no.1
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• pp.19-25
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• 1979

To determine the metabolism of leucine during the cuticle formation and the sclerotization process in Pieris rapae L., $U-^3$H-leucine or $U-^4$C-tyrosine is injected into the haemolymph of newly molted pupa through dorsal cuticle of heart area. The results show that leucine as a common amino acid participates in the synthesis of cuticle protein over the first 3 hr after ecdysis. It is also shown that leucine in the haemolymph at ecdysis is freely being moved between major internal organs during the short time period post-ecdysis, providing the evidence for some involvements including haemolymph protein synthesis and storage of fat body and gut in metabolism of leucine.

• Biomedical Science Letters
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• v.27 no.4
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• pp.239-247
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• 2021

The scuttle fly is a fly species in the Phoridae family. Scuttle fly which moves abruptly after standing for a while and stop suddenly to rush off again. These characteristic behaviors of the scuttle fly seem to be related to muscular and nervous system or neurotransmitters. Thus, we focused at the neurotransmitter, corazonin (Crz) that is known to be related to resistance to stress and investigated the developmental process of the neurons in the scuttle fly. In a previous studies, we found that there are three groups of corazoninergic neurons in the larval CNS of the scuttle. Larva has 3 pairs of Crz neurons at the dorsolateral area of the brain, 1 pair at the dorsomedial brain and 8 pairs at the ventral nerve cord. In this studies, among these neurons, 1 pair of dorsomedial brain and 8 pairs of ventral nerve cord disappear in early pupal stage after metamorphosis. Only the 3 pairs of dorsolateral brain persist expression of Crz gene through all the period of pupa stage. This group of neurons converge gradually to frontal center of the brain and situated at the medial region. These pairs of corazoninergic neurons keep their number and location in adult stage. In the future, we expect further studies on the histological characteristics of corazonin-expressing cells and the expression of corazonin gene.

• International Journal of Industrial Entomology and Biomaterials
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• v.46 no.2
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• pp.60-66
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• 2023

Osteoarthritis (OA) is one of the most prevalent degenerative joint diseases and is more common in older and obese individuals. Silkworm male pupae exerts tonic effects by increasing testosterone secretion and the forced swimming time and muscle ratio increased in mice consuming silkworm pupae, which may be beneficial to the older population. Therefore, it will be beneficial to investigate the effects of silkworm pupal extracts (SPE) on OA. To confirm this effect, we prepared SPE in different solvents, and their ability to attenuate matrix metalloproteinases (MMPs) and inflammatory mediators (interleukin-6 [IL-6], interleukin-8 [IL-8] and tumor necrosis factor-α [TNF-α]) were evaluated in an interleukin-1β (IL-1β)-induced SW1353 human chondrosarcoma cell line. 70% ethanolic SPE outperformed the other solvents, reducing MMP-1 and MMP-3 expression by up to 53% and 13%, respectively. Further experiments were performed using 70% ethanolic SPE from three distinct pupation stages in males and females. SPE treatment alleviated MMP-1 expression (43.9-47.4%) regardless of pupation stage and sex. Among the inflammatory mediators, 70% ethanolic SPE alleviated IL-6 and TNF-α levels, and the concentrations thereof were lowest in the early-stage male SPE-treated group (43.15% and 56.74%, respectively). In conclusion, 70% ethanolic SPE may prevent IL-1β-induced osteoarthritis by inhibiting MMPs and inflammatory cytokines. Therefore, SPE is a potential therapeutic agent for the treatment of OA.

• The Korean Journal of Zoology
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• v.25 no.2
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• pp.63-70
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• 1982

The activity, properties, and distribution of midgut protease during metamorphosis in Pieris rapae L. are determined using spectrophotometer, ultracentrifuge and agar gel electrophoresis. Proteolytic activity of midgut reaches the peak just before ecdysis in 5th instar and prepupal stages each but 1 day after ecdysis in pupal stage. Also, optimum pH of midgut protease is pH 8.0 in 5th instar stage, pH 6.5 in prepupal stage, and pH 8.5 immediately before emergence respectively. Protease is found mostly in midght tissue in 5th instar stage but thereafter until just before emergence the enzyme only in lumen contents, suggesting that protease is synthesized in midgut tissue during larval stage and then released into lumen during pupation period.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.63-67
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• 2016

This study examined the biological characteristics of Meganoton scribae under the following conditions: temperature (20, 25, $30^{\circ}C$), humidity ($60{\pm}10%$), and photoperiod (14L:10D). At $25^{\circ}C$, the larval stage of M. scribae lasted for 28.4 d, and the pupal stage for 15.6 d. The average head width was 0.96 mm in the $1^{st}$, 1.34 mm in the $2^{nd}$, 2.07 mm in the $3^{rd}$, 3.64 mm in the $4^{th}$, and 5.89 mm in the $5^{th}$ instar. The life span of female adults was 10.3 d, and the maximum number of eggs spawned was 257.7. The results of the study will be useful for the commercial development of M. scribae.

• Biomedical Science Letters
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• v.29 no.4
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• pp.330-335
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• 2023

The corazonin (Crz) gene showed two subtypes of different length at laval and pupal stage. The long subtype fade out in adult central nerve system (CNS) but the short one survive through all the life cycle from larva to adult. The short subtype has the same base sequences with mature Crz mRNA and detected in both brain and ventral nerve cord (VNC). The long one, on the contrary, was detected only in the brain tissue. As observed in above results, Crz neurons develop in different pattern in the CNS of scuttle fly and the Crz gene expresses two different subtypes. These results suggest that this neurotransmitter may perform differential neurophysiological functions in the scuttle fly. Variation in the amino acid composition of the final active undecapeptide supports in strong those possibilities. We expect further studies on the relationship between neurophysiological functions of Crz and behavioral characteristics of the scuttle fly.

• Applied Microscopy
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• v.12 no.2
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• pp.35-44
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• 1982

The fat bodies of cabbage worm (Pieris rapae) and silk worm (Bomyx mori) during metamorphosis was comparatively studied by electron microscope. 1. Cell oranelles: Golgi apparatus were not observed in both species. It is observed that RER of cabbage worms initiate to degenerate in prepupa stage with complete degeneration at adult stage, while that of silk worms shows similar degenerative pattern. However, mitochondria of cabbage worms are transformed into autophagic vacuole from prepupa stage until adult stage whereas those of silk worm shows a decrease in number in prepupa stage but maintains a certain level until adult stage. 2. Storage substance in cell: Lipid droplets in cabbage worms were observed to increase in numbers during larval stage but afterward decrease in number with an enlargement in size. However immediately after their pupal stage, they almost disappear. On the contrary lipid droplets in silk worms show rather increase in number until adult stage. Protein storage granules in bothspecies were arised from autophagic vacuoles(lysosome) . Fat cells of cabbage worm in adult stage turn out to be residual bodies which last until final stage, but those of silk worm rapidly decrease. Glycogen particles in both species reach maximum at last larval instar and thee gradually decrease thereafter. 3. Fat body sheath: The average width of fat body sheath was measured to be $0.2{\mu}m$ and $0.6{\mu}m$ and surface of fat cells adjacent to fat body sheath in silk worm is heavily infolded.

• The Korean Journal of Zoology
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• v.23 no.3
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• pp.125-136
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• 1980

The purpose of the present study is to investigate the electrophoretic patterns of ADH isozymes and activity at various developmental stages of Oregon-R and Kwangju strains of D. melanogaster. The ADH isozymes were seperated by agarose gel plate eletrophoresis and they were stained for ADH activity study. The optical density was measured by using densitometer and the total activity was determined by measuring the enzyme solution's absorbance of 340 nm by spectrophotometer. The results are as follows: 1. At egg stages of Oregon-R and Kwangju strains ADH 2, ADH 3, ADH 4 were observed in te zymograms, but all of ADH 1, ADH 2, ADH 3, ADH 4 and ADH 5 were detected in larval, pupal and imaginal stages. 2. The amount of ADH 1+ADH 2 (anion) was 20-40% and that of ADH 3+ADH 4+ADH 5 (cation) was 60-805. In the developmental stages other, than egg stages, ADH 3 of both strains showed the largest amount among all ADH isozymes, and especially ADH 4 of Kwangju strain showed less amount than that of Oregon-R strain. 3. The total activity of the ADH at the egg stage was found to be the lowest, at larval stage became to be higher and to be lower at pupal stage and then became to be the highest at the imaginal stage. It is noticeable that the activity of the ADH in Kwangju strain was higher than that in Oregon-R strain.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.101-106
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• 2005

In this study, we describe the Bombyx mandarina hemolin cDNA. A sequence analysis of cDNA revealed a single open reading frame (ORF) of 1233 nucleotides. The deduced 410 amino acid sequence of B. mandarina hemolin contains 4 imunoglobulin (Ig) C-2 type domains. B. mandarina hemolin cDNA showed the highest sequence homology to known those of B. mori. The developmental profile in terms of expression level of hemolin mRNA was determined in the absence of a bacterial challenge. Hemolin mRNA was detected only in mid-gut, but not in hemocytes, fat body, testis, and silkglands. Hemolin mRNA in mid-gut was not detected until the spinning stage of the last instar larva, however, lit dramatically increased at the beginning of spinning and gradually decreased until pupal stage.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.1
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• pp.11-17
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• 2005

In our research to identify gene involved in the cuticle protein, we cloned a novel cuticle protein gene, ApCP15.5, from the Chinese oak silkmoth, Antheraea pernyi, larvae cDNA library. The gene encodes a 149 amino acid polypeptide with a predicted molecular mass of 15.5 kDa and a pI of 9.54. The ApCP15.5 contained a type-specific consensus sequence identifiable in other insect cuticle proteins and the deduced amino acid sequence of the ApCP15.5 cDNA is most homologous to Tenebrio molitor-C1B ($43\%$ protein sequence identity), followed by Locusta migratoria-76 ($42\%$ protein sequence identity). Northern blot and Western blot analyses revealed that the ApCP15.5 showed the epidermis-specific expression. The expression profile of ApCP15.5 indicated that the ApCP15.5 mRNA expression was detected in the early stages after larval ecdysis and larval-pupal metamorphosis, and its expression level was most significant on the first day of larval ecdysis and pupal stage. The ApCP15.5 was expressed as a 15.5 kDa polypeptide in baculovirus-infected insect cells.