• 대한의생명과학회지
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• 제28권4호
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• pp.290-297
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• 2022

Through previous studies, the central nervous system (CNS) was collected by dividing the scuttle fly into larval, pupa, and adult stages by developmental stage, and the morphological characteristics were observed. In situ hybridization (ISH) using the collected central nervous system, it was possible to confirm the location and extent of expression of the neurotransmitter corazonin (Crz) at each stage of development. In this study, paraffin specimens were prepared using central nervous system tissues of 3rd instar larval stage of scuttle fly, which had completed in situ hybridization, and general histochemical staining (hematoxylin-eosin, H-E) and special histochemical staining (luxol fast blue-cresyl violet) was performed to observe the histological and cytological morphology characteristics of corazonin neurons. As a result, a variety of nerve cell body existed between many myelin sheath. The corazonin neurons compose cortex of central nervous system with other neurons congregating in this tissue and show larger cell body relatively in neurohistochemical analysis.

• Parasites, Hosts and Diseases
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• 제55권1호
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• pp.47-54
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• 2017

The prevalence of cercarial infection in freshwater snails and their evolutionary trends were studied in Nakhon Nayok province, Thailand. A total of 2,869 individual snails were examined for parasitic infections. The results showed that 12 snail species were found to host larval stages of trematodes with an overall prevalence of 4.7%. The infected specimens included 7 types at the cercarial stage; cercariae, megalurous cercariae, echinostome cercariae, furcocercous cercariae, parapleurolophocercous cercariae, virgulate cercariae, and xiphidiocercariae. Regarding molecular identification, ITS2 sequence data of each larval trematode were analyzed, and a dendrogram was constructed using the neighbor-joining method with 10,000 replicates. The dendrogram was separated into 6 clades (order/family), including Echinostomatida/Echinostomatidae, Echinostomatida/Philophthalmidae, Opisthorchiida/Heterophyidae, Plagiorchiida/Prosthogonimidae, Plagiorchiida/Lecithodendriidae, and Strigeatida/Cyathocotylidae. These findings were used to confirm morphological characteristics and evolutionary trends of each type of cercariae discovered in Nakhon Nayok province. Furthermore, this investigation confirmed that the ITS2 data of cercariae could be used to study on phylogenetic relationships or to determine classification of this species at order and/or family level when possible.

• 한국수산과학회지
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• 제23권6호
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• pp.457-467
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• 1990

Sessile barnacle, Balanus trigonus Darwin, was collected from the intertidal rocks and the external shells of bivalve Mylius coruscus. The nauplius and cyprid larvae were cultured in a constant temperature cabinet at a temperature of $20^{\circ}C$ and a light regime of 14 h light and 10 h darkness. Larval development includes the six nauplius stages and a cyprid stage prior to settlement and metamorphosis to the young adult. Morphological characteristics including antennules, antennae and mandibles are described and illustrated. All nauplius larvae have trilobed labra typical in balanoides. The developmental time taken from newly hatched nauplius I to cyprid was $9\~13$ days and averaged 11 days.

• Applied Microscopy
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• 제43권1호
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• pp.21-26
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• 2013

The oriental fruit moth (Grapholita molesta Busck) and the peach fruit moth (Carposina sasakii Matsumura) are the most severe insect pests affecting apple orchards in Korea. To prevent an outbreak of these two species and to control these agricultural insect pests, it is important to identify them accurately. However, it is hard to classify them when they were in the larval stage since they tunnel into the apple fruit. In this study, surface structures of the two species of larvae were observed using stereo microscope and scanning electron microscope. Distinct differences between the two species of larvae were found. The prothorax spiracles of oriental fruit moth larvae were approximately twice as large as those of peach fruit moth larvae. The arrangements of subventral setae, located around the proleg, were different between oriental fruit moth and peach fruit moth larvae. Furthermore, subdorsal setae of oriental fruit moth were located next to the spiracle on the 8th abdominal segment, while that of peach fruit moth was located above the spiracle. The identification of the two species of larvae observed in this study was confirmed using polymerase chain reaction-restriction fragment length polymorphism method. Surface structural differences are intrinsic characteristics for each species of larvae and can easily be identified using stereo microscope. These specificities will be helpful where a large number of field-collected larvae need to be identified routinely in pest control research.

• Parasites, Hosts and Diseases
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• 제34권3호
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• pp.161-168
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• 1996

중국산 수입 미꾸리로부터 획득한 악구충 유충의 형태학적 특징을 관찰하고 종 동정하고자 하였다. Early third-stage larva($EL_3$)는 중국산 미꾸리의 내장에서 분리 수집하였고 advanced third-stage larva($AdL_3$)는 $EL_3$를 마우스에 실험감염시킨 후 4주에 회수하였다 미꾸리 및 마우 스로부터 획득한 충체들을 10% formalin으로 고정하였고 alcohol-glycerin 용액을 거쳐 glycerinfelly로 봉입한 후 관찰 및 계측하였다. 총 9 493마리의 중국산 미꾸리를 조사하였던 바 총 369마리의 $EL_3$가 검출되었다. $EL_3$는 평균 0.624{\;}{\times}{\;}0.101 mm 크기이었고 체표면에 약 190 줄의 가로주름(transverse striation)이 나 있었으며 각 주름에는 미세한 가시(cuticularspine)들 이 일정한 간격으로 배열되어 있었다. 충체의 전단에는 1쌍의 구순이 돌출되어 있었고 그 뒤로 근 육성의 인두(평균 0.229 mal)와 갈색의 장이 이어졌으며 후단 근처의 복측에 항문이 개구하였다 특징적인 head bulb(평균 0.034{\;}{\times}{\;}0.071 mm)에는 소구(hooklets)가 평균 36 7개, 39.5개, 41.6개 및 44.3개씩 4줄 배열되어 있었고 head bulb 바로 뒤에는 2쌍의 cervical sac(평균 0.133 mm)이 인두를 따라 길이로 배열되어 있었다. AdLB는 평균 $2.660{\;}{\times}{\;}0.346{\;}mm$ 크기이었고 충체 전단의 구순 특징적인 head bulb(평균 $0.097{\;}{\times}{\;}0.193{\;}mm$), 근육성의 인두(평균 0.755 mm), 2쌍의 cewicalsac(평균 0.355 mm). 갈색의 장 등을 가지고 있었다 대부분의 충체 head bulb에는 소구가 평균 39.0개, 41 9개, 43.9개 및 45.6개씩 4줄 배열되어 있었으나 몇 몇 충체에서는 5번째 줄에 3~7개의 소구가 배열되어 있었다. 이상의 형태학적 특징 및 계측치를 토대로 하여 중국산 수입 미꾸리와 실험감염 마우스로부터 획득한 악구충을 돼지악구충 (Gnathostoma hispidum)의 제3기 유충으로 동정하였다.

• 한국어류학회지
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• 제13권1호
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• pp.74-84
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• 2001

사육 조건하에서 동자개 Pseudobagrus fulvidraco의 발육에 따른 형태 변화 및 상대성장에 대해 검토하여 발육단계를 구분한 결과를 요약하면 다음과 같다. 1. 수정난은 난경 2.04${\pm}$0.07 mm (n = 100)의 비교적 큰 구형의 분리되는 침성부착난으로서 수조의 바닥 및 기질에 강하게 부착한다. 2. 부화자어는 전장 약 4.92${\pm}$0.33 mm로, 부화 후 1일에 입이 열리고, 부화 2일후에는 항문이 열리고, 부화 후 3일에 섭이를 시작하여 후기자어기에, 부화 후 30일경에 전장 약 32 mm에 유어기에 이른다. 3. 전장에 대한 각 부위의 상대성장에 굴곡점은 전장 7~8 mm, 17~32 mm, 32 mm 전후에 집중적으로 나타났다. 4. 외부형태의 변화 및 상대성장의 굴곡점이 나타나는 어체 크기 등을 종합적으로 고려하여 자어기에서 유어기까지의 발육단계를 구분하면, 자어기는 전장 17 mm 이하, 치어기는 17~32 mm, 유어기는 32 mm 이상으로 사료된다. 상대성장의 측정결과 전기자어기에는 머리부분에 관련된 형질, 후기자어기 이후에는 운동능력에 관련된 형질의 우성장이 뚜렷하였다.

• Parasites, Hosts and Diseases
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• 제45권3호
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• pp.191-198
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• 2007

A total of 205 larval gnathostomes were collected from 18 (22.5%) of 80 red banded odd-tooth snakes, Dinodon rufozonatum rufozonatum, which had been smuggled from China and confiscated at Customs in Susan, Republic of Korea. In order to identify the species, some of the larvae were observed by a light microscope and a scanning electron microscope (SEM). The larvae were $2.18{\times}0.29mm$ in average size, and had a pair of lips at the anterior end, a muscular esophagus, 2 pairs of cervical sacs, and brownish intestines. The head bulb was characteristically equipped with 4 rows of hooklets; the average number of hooklets in each respective row was 38.6, 40.5, 41.5, and 43.7. In SEM views, the mouth evidenced a pair of lateral lips of equal size in a half-moon shape. Each lip featured a couple of labial papillae and a small amphid located between the 2 papillae. The hooklets on the head bulb had single-pointed, posteriorly-curved tips. The cuticular spines were larger and more densely distributed on the anterior part of the body, and decreased gradually in size and number toward the posterior body. On the basis of these morphological characteristics, the larvae were identified as the third stage larvae of Gnathostoma hispidum.

• 한국응용곤충학회지
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• 제42권1호
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• pp.1-7
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• 2003

고구마를 가해하는 됫날개흰밤나방(Aedia leucomelas)의 형태적 특징과 온도에 따른 발육특성 그리고 발생소장 및 고구마 가해양상을 1999부터 2000년까지 실내와 고구마포장에서 조사하였다. 성충은 흑갈색으로 체장은 암컷이 20.2mm,수컷이 18.9mm이었고, 날개 편 길이는 각각 33.7mm, 29.4mm이었다. 난은 납작한 원형이며, 유충은 엷은 황녹색-짙은 회색으로 체장은 3.3-53.5 mm이고, 번데기는 진한 갈색으로 체장은 15.1 mm이었다. 난부터 우화까지의 평균발육기 간은 15, 20, 25, 3$0^{\circ}C$ (60$\pm$5% RH, 16L : 8D)에서 각각 108.5, 70:7, 40.2, 29.1일로 온도가 증가할수록 발육기간이 짧아졌다. 각 태별 발육영점온도와 유효적산온도는 난은 10.7$^{\circ}$C와 67.5일도, 유충은 11.0$^{\circ}$C와 275.1일도, 번데기는 9.3$^{\circ}$C와 244.6일도 이었다. 암컷의 수명은 위 조사온도에서 각각 14.6, 12.8, 11.1, 10.3일이었고, 산란수는 각각 43, 189,244,265개로 성충수명은 고온일수록 짧아졌지만 산란수는 증가하였다. 됫날개흰밤나방 유충은 고구마 포장에서 6월 중순부터 10월까지 발생되었는데 9월 상-중순에 발생량이 가장 많았다. 유충의 섭식량은 20-$25^{\circ}C$에서 가장 많았고, 25$^{\circ}$C에서 1령, 2령, 3령, 4령, 5령 유충의 1일 섭식량은 각각 0.4, 3.6, 19.6, 40.7, 78.9$\textrm{cm}^2$ 였다.

• Parasites, Hosts and Diseases
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• 제60권5호
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• pp.345-352
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• 2022

Chitinase AO-801 is a hydrolase secreted by Arthrobotrys oligospora during nematode feeding, while its role remained elusive. This study analyzed the molecular characteristics of recombinant chitinase of Arthrobotrys oligospora (reAO-801). AO-801 belongs to the typical glycoside hydrolase 18 family with conserved chitinase sequence and tertiary structure of (α/β)₈ triose-phosphate isomerase (TIM) barrel. The molecular weight of reAO-801 was 42 kDa. reAO-801 effectively degraded colloidal and powdered chitin, egg lysate, and stage I larval lysate of Caenorhabditis elegans. The activity of reAO-801 reached its peak at 40℃ and pH values between 4-7. Enzyme activity was inhibited by Zn2⁺, Ca2⁺, and Fe3⁺, whereas Mg2⁺ and K⁺ potentiated its activity. In addition, urea, sodium dodecyl sulfate, and 2-mercaptoethanol significantly inhibited enzyme activity. reAO-801 showed complete nematicidal activity against C. elegans stage I larvae. reAO-801 broke down the C. elegans egg shells, causing them to die or die prematurely by hatching the eggs. It also invoked degradation of Haemonchus contortus eggs, resulting in apparent changes in the morphological structure. This study demonstrated the cytotoxic effect of reAO-801, which laid the foundation for further dissecting the mechanism of nematode infestation by A. oligospora.

• 한국패류학회지
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• 제30권4호
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• pp.303-309
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• 2014

코끼리조개의 대량 인공종묘생산을 추진하기 위한 기초연구로서 수정란, 유생 및 치패의 발달을 조사하였다. 생식체는 잘 성숙한 어미에서 추출하여 희석 정자 용액으로 수정하였으며, 발생유생은 수온 $19{\pm}1^{\circ}C$로 유지하였다. 수정란의 난경은 평균 $81.6{\mu}m$ 이었으며, 수정 후 14시간 만에 담륜자 유생이 되어 부상하고, 27시간 만에 D상 유생 (각장 $116{\mu}m$)으로 발달하고, 20일 후에는 각장 $311.2{\mu}m$로 성장하여 바닥에 안착하였다. $18.5-21.5^{\circ}C$에서 정상적으로 부화 및 유생사육이 가능하였으며, 채묘기질은 모래가 우수하였으나 캐시미론도 양호하였다. 부유유생이 착저한 후 108일간 사육한 결과 각장 13 mm, 전중량 0.4 g으로 성장하였고 일간성장률은 각장 $117.5{\mu}m$ 이었으며, 자연해수로 연중 실내육성이 가능하였다.