The Asian corn borer, Ostrinia furnacalis, is a serious insect pest that can infest corn leaves and stems. Due to its internal feeding behavior, its larvae are not exposed to insecticides that are ...usually sprayed for pest control. To minimize crop damage caused by O. furnacalis, improving insect resistance trait of corn has been considered as an optimal control tactic. This study screened 27 corn varieties for their insect resistance trait and selected three varieties of Ilmichal (IM), P3394, and Kwangpyeongok (KP) that showed insect resistance trait. O. furnacalis larvae did not show any significant difference in preference between these three insect-resistant corn varieties and a control susceptible variety. However, these resistant varieties after ingestion significantly interfered with larval development of O. furnacalis. This suggests that the insect resistance trait is induced by antibiosis, but not by antixenosis. Indeed, larvae fed with these varieties suffered from low chymotrypsin (CHY) activities in the midgut juice. To determine the target CHY inhibited by resistant corn varieties, a total of nine CHY genes (Of-CHY1~Of-CHY9) were predicted from the transcriptome of O. furnacalis. Six genes (Of-CHY1~Of-CHY6) were expressed in all developmental stages and tissues. Especially, Of-CHY3 was highly expressed in the midgut of O. furnacalis larvae. RNA interference (RNAi) using double-stranded RNA (dsRNA) specific to Of-CHY3 (2 μg of dsRNA injected to each L5 larva) resulted in significant reduction of Of-CHY3 expression level at 24 h post-treatment. Feeding L3 larvae with this dsRNA also significantly suppressed the expression level of Of-CHY3 and reduced its enzyme activity at 24 h post-treatment. A recombinant Escherichia coli expressing dsRNA specific to Of-CHY3 was constructed using L4440 vector. Feeding such recombinant bacteria suppressed the expression level of Of-CHY3 and prevented larval development of O. furnacalis. These results suggest that the three resistant varieties can produce a resistance factor(s) to inhibit the CHY activity of O. furnacalis and suppress larval growth. This study suggests that CHY might be an inhibition target in O. furnacalis for breeding insect-resistant corns.
열대거세미나방(Spodoptera frugiperda)(밤나방과) 유충 사육을 위해 이전에 개발된 두 인공사료(N4와 N6)가 뒷흰가는줄무늬밤나방 (Mythimna loreyi)(밤나방과) 사육에도 적합하였다. 실험실 조건25°C, 15:9 h (명:암) 광주기에서 알기간은 4.9–5.2일, 유충기간은 22.3-23.2일로 두 사료 집단 사이에 큰 차이가 ...없었다. 한 사료 집단 내에서 번데기 기간은 암컷이 약 12.6-12.8일, 수컷이 14.1–14.5일이었고, 번데기 무게는 암컷 이 약 345 mg, 수컷이 약 380 mg로, 암수 사이에 유의한 차이를 보였다. 유충의 용화율과 용의 우화율은 각각 91-94%와 91-95%로 두 사료집단 사 에의 유의한 차이를 보이지 않았다. 성충 산란전 기간은 3.4일, 산란기간은 약 4.7-4.8일 이었다. 성충 수명은 암컷이 8.2일, 수컷이 10.3-12.4일로 수컷의 수명이 길었다. 암컷당 부화한 총 자손 수는 724-847마리였고, 최대 약 1,400마리였다. 생명표 분석에서 개체군 내적자연증가율(N4 집단 0.1181, N6 집단 0.1253)은 두 사료집단 사이에 유의한 차이가 없었다. 한 사료집단 내에서 유충 영기가 5령 혹은 6령까지 발육하는 개체변이가 발 견되었다. N4 사료집단의 5령 개체 비율(약 22%)은 N6 사료집단의 5령 개체비율(약 7%)보다 높았다. 6령 개체들의 평균 유충기간이 5령 개체들보 다 더 길었다. 유충의 영기별 두폭은 1령의 약 308 μm부터 6령의 약 3,065 μm까지, 몸길이는 1령의 약 2.0 mm부터 6령의 약 29.1 mm까지 측정 되었다. 2020년 6-7월 중에 옥수수 포장에서 뒷흰가는줄무늬밤나방 유충이 동속종인 멸강나방(M. separata) 유충과 함께 발견되었다.
The two previously developed artificial diets (N4 and N6) used for rearing Spodoptera frugiperda (Noctuidae) larvae, were selected as highly-fit ones for rearing Mythimna loreyi larvae. Almost all biological characteristics were not significantly different between the colonies reared on the two diets at 25°C and 15:9 h (light:dark) photoperiod. The developmental periods were 4.9–5.2 days for eggs, and 22.3-23.2 days for larvae. The pupal period and weight were different between the sexes in each diet colony. The pupal periods in females and males showed 12.6-12.8 days and 14.1-14.5 days, respectively. The pupal weights were ca. 345 mg for females and ca. 380 mg for males. The pupation and emergence rates were ca. 91-94%, and ca. 91-95%, respectively, without significant differences between the two colonies. The pre-oviposition and oviposition periods were 3.4 days and 4.7-4.8 days, respectively. The adult longevity was 8.2 days in females and 10.3-12.4 days in males. Total offsprings produced were found to be 724-847 larvae on an average with ca. 1,400 maximum larvae. In the life table analysis, the intrinsic rates of increases (0.1181 for N4 and 0.1253 for N6) were not significantly different between the two colonies. Individual differences in the larval instar number 5 and 6 were found within a diet colony. The ratios of 5-instar larvae were ca. 22% in N4 colony and ca. 7% in N6 colony. The larval period of 6-instar larvae was longer than that of 5-instar larvae. Width of head capsule in larvae varied from ca. 309 μm for 1st instar to ca. 3,065 μm for 6th instar. Body lengths measured from ca. 2.0 mm for 1st instar to ca. 29.1 mm for 6th instar. Larvae of M. loreyi and M. separata were found at the same time in a maize field during June and July, 2020.
벼 해충인 이화명나방(Chilo suppressalis)(포충나방과) 유충을 사육하기 위해 맥아, 콩, 옥수수, 효모, 설탕, 카세인, 콜레스테롤, 베타시토 스테롤, 거대억새 건조 가루를 주 영양성분으로 구성한 인공사료를 개발하였다. 25°C와 광주기 15:9 시간 명:암 조건에서 갓부화 1령 유충을 개체별로 성충 우화 때까지 사육하였을 때, 용화율이 ...82.2%, 우화율이 98.6%였다. 유충 발육기간은 암컷이 평균 34.6일, 수컷이 31.0일이었고, 번데기 기간은 암컷이 8.9일, 수컷이 9.7일로 성별 간에 유의한 차이가 있었다. 번데기 무게는 암컷이 평균 75.0 mg, 수컷이 57.0 mg으로 암컷이 통계적으로 유의하게 무거웠다.
An artificial diet containing wheat germ, soybean, corn, yeast, sucrose, casein, cholesterol, β-sitosterol, and dry Miscanthus sacchariflorus stem powder was developed for rearing Chilo suppressalis (Crambidae) larvae. Neonate larvae were individually raised on the diet till adult emergence at 25°C and 15:9 h light:dark photoperiod. In the results, the pupation and the emergence rates were 82.2% and 98.6%, respectively. The mean developmental periods of female and male larvae were 34.6 days and 31.0 days, respectively, whereas the pupal periods of female and male were 8.9 days and 9.7 days, respectively. Those periods were significantly different between genders. The mean pupal weights of female and male were 75.0 mg and 57.0 mg, respectively, with significant difference.
수원지방에서 콩과 옥수수에 대한 잠재적인 해충으로 밤나방과의 열대거세미나방(Spodoptera frugiperda)과 담배거세미나방(S. litura), 파밤나방(S. exigua), 콩은무늬밤나방(Ctenoplusia agnata), 뒷흰가는줄무늬밤나방(Mythimna loreyi ), 뒷흰날개담색밤나방(Athetis dissimilis), 꼬마 ...담색밤나방(A. lepigone)을 수컷 성충의 날개 무늬와 생식기 형태 및 미토콘드리아 시토크롬 옥시다제 1 유전자 부분 염기서열을 비교하여 해당 종들을 동정하였다. 꼬마담색밤나방을 제외한 6종에 대해서는, 2019년 성페로몬트랩에서 관찰된 연중 밀도변동 자료와 온도에 따른 발육과 생식 모델들을 이용하여 관찰 세대로부터 다음 세대 성충의 발생시기를 예측한 자료로, 해당 종이 1년 안에 성충 세대가 몇 회 연속하여 발생할 수 있는가 추정하였다. 열대거세미나방은 7월 27일부터 10월 31일까지 포획되었는데, 수원 지방의 자료만으로는 3회 성충이 발생하는 것으로 추정되었다. 그러나 다른 지방에서 관찰된 6월 중하순의 유충 발생 자료를 고려하여, 수원지방에도 연중 4회 성충이 발생할 수 있을 것으로 추정되었다. 담 배거세미나방은 5월 29일부터 11월 6일까지 포획되었고, 파밤나방은 5월 14일부터 11월 6일까지, 콩은무늬밤나방은 5월 26일부터 10월 25일 까지, 뒷흰가는줄무늬밤나방은 5월 31일부터 11월 23일까지 포획되었다. 이들 4종도 성충 세대가 연중 최소한 4회 발생할 것으로 추정되었다. 뒷흰날개담색밤나방은 5월 26일부터 9월 11일까지 포획되었고, 연 2회 발생이 추정되었다. 두 종의 Athetis속 나방을 제외한 다른 다섯 종들의 첫 발생 성충세대들은 다른 지역으로부터 비래했을 것으로 가정되었다.
Adults of seven noctuid potential pests (Spodoptera frugiperda, S. litura, S. exigua, Ctenoplusia agnata, Mythimna loreyi, Athetis dissimilis, and A. lepigone) of soybean and maize in Suwon, Korea were identified by their morphological characteristics in the wing pattern and male genitalia and partial mitochondrial DNA sequences of cytochrome c oxidase subunit 1 gene. The generation number of adults that emerge annually in six species (except A. lepigone) was estimated from the data on density fluctuations of adults caught in sex pheromone traps in 2019 and the forecasted data using temperature-associated development and reproduction models for those species. S. frugiperda adults were caught from July 27th to October 31st in 2019, and hence were initially estimated to emerge three times per year. But, it was finally expected that S. frugiperda adults could possibly emerge a total of four times per year in Suwon, considering larval emergence observed during mid- and late June in other areas. Adult emergence of S. litura, S. exigua, C. agnata, and M. loreyi in 2019 was observed from May 29th to November 6th, from May 14th to November 6th, from May 26th to October 25th, and from May 31st to November 23rd, respectively. Annual adult emergence of these four species was estimated as at least four times. Adults of A. dissimilis were caught from May 26th to September 11th in 2019, and adult emergence was estimated at only twice per annum. It was postulated that the first adult populations of five species except the two Athetis species were probably migrated from other areas.
수원 지방에서 조명나방(Ostrinia furnacalis)(나비목: 포충나방과) 성충 발생횟수와 유충 휴면이 유도되는 시기를 분석하였다. 성충은 일년 에 3회 발생 하였는데, 1화기는 5월 초부터 7월 초까지, 2화기는 7월 초중순부터 8월 초중순까지, 3화기는 8월 중순부터 10월까지이었다. 7월말 부터 8월 중순 사이에 갓부화 유충을 야외에서 ...사육하기 시작하였을 때, 그 해와 이듬해 용화한 개체들이 같이 발생하였다. 이후 사육된 집단에서 는 모두 월동 유충들만 출현하였다. 야외에서 7월과 8월 중 채집된 유충들에서는 월동하거나 월동하지 않는 개체들이 같이 발생하였고, 이후 채집 된 개체들에서는 모두 월동하는 개체들만 나타났다. 이 결과들은 수원에서 조명나방은 연중 2세대와 3세대를 경과하는 개체들이 같이 발생하는 복합 생활사를 갖는 것을 보였다. 실험실에서, 조명나방 유충을 영기별로 탈피 직후(9시간 이내)에 휴면유도 조건(11:13 시간 = 명:암 광주기, 20°C)에 처음 처리하였을 때, 거의 모든 유충들에서 휴면이 유도되었다. 유사한 처리를 5령으로 탈피한 유충 나이별로 적용하였을 때, 5령 3일과 4일 나이의 유충에 대한 처리에서는 휴면유도율이 감소하였다. 한편 알에서 갓 부화했을 때부터 휴면유도 조건에서 사육하던 유충들을 3령, 4령, 5령 탈피 직후에 비휴면 조건으로 옮겼을 때, 거의 대부분의 유충들은 휴면에 유도되지 않았다. 그 결과로부터 5령 초기 나이의 유충들이 휴면유도 자극에 반응하는 최종 단계라고 추정되었다. 비휴면 유충들에 비해, 휴면이 유도된 유충들에서는 혈림프 내 트레할로스 함량이 증가하였고, 몸체 과냉각점이 낮아졌다.
The diapause induction season in Ostrinia furnacalis (Lepidoptera: Crambidae) was estimated in Suwon. Three batches of adult generations were observed, the first one from early May to early July, the second from early or mid-July to early or mid-August, and the third from mid-August to October. In outdoor larval rearing, colony rearing occurring from mid-July to mid-August produced both non-overwintering and overwintering larvae, whereas late-reared colonies produced only overwintering larvae. Larvae collected during July and August in maize fields produced both non-overwintering and overwintering larvae, whereas late-collected larvae produced only overwintering larvae. The results indicated that O. furnacalis has a bi- or trivoltine complex life cycle in this area. In the laboratory, when larvae of all instars within 9 h after molting were first treated to a diapause induction condition (11:13 h = light:dark photoperiod and 20°C), almost all larvae were induced to diapause. However, when similar treatments were conducted age-specifically for the 5th instar larvae, diapause induction rates in 3- and 4-day-old larvae of the 5th instar decreased. In contrast, when larvae were subjected to the diapause induction treatment only during the periods from the hatching stage to the 2nd, 3rd, and 4th instar, almost all larvae were not induced to diapause. The results suggest that the early age of the 5th larval instar is the last stage for sensitivity to diapause induction stimuli. In the diapause-induced larvae, hemolymph trehalose content increased and body supercooling points dropped, compared with those in non-diapause larvae.
열대거세미나방(Spodoptera frugiperda)(밤나방과) 유충을 사육하기 위해 강낭콩과 맥아, 콩, 전지분유, 설탕을 주 영양분으로 구성한 두 종류(N4와 N6)의 반합성 인공사료를 개발하였다. 25oC와 광주기 15:9 h(명:암) 조건으로 페트리접시(지름 50 × 10 mm, 19.6 cm3) 안에서 1령 유충을 각 사료로 개체별로 사육하였을 ...때, 6령 유충까지 관찰되었다. 용화율은 N4에서 평균 97.8%로 N6의 85.6%에 비해 유의하게 높았다. 번데기의 우화율은 각각 92.0과 93.5%로 유의한 차이는 없었다. 암컷 유충의 발육기간은 N4에서 17.9일, N6에서 17.7일이었고 수컷은 N4에서 18.7일, N6에서 18.5일이었는데, 사료 및 암수 사이에 차이는 없었다. 번데기 기간은 암컷이 11.1일, 수컷은 12.8일로 각 사료에서 동일하였는 데, 암수 사이에는 유의한 차이가 있었다. 번데기 무게는 N4에서 257 mg로 암수가 동일하였고 N6 사료에서는 암컷이 256 mg, 수컷이 263 mg 이었는데, 사료 및 암수 사이에 차이는 없었다. 각 사료로 자란 암컷 성충의 수명은 N4에서 8.6일에 비해 N6가 13.8일로 길었다. 산란전 기간은 N4에서 5.0일, N6에서 4.2일로 차이는 없었다. 산란기간은 N6사료에서 6.5일로 N4의 3.9일 보다 유의하게 길었다. 암컷당 유효 산란수는 N6 에서 1,392개(최대 1,776개)로 N4사료에서의 942개(최대 1,694개)보다 많았으나, 사료 사이에 유의한 차이는 나타나지 않았다. N4와 N6 각각 에서 알의 부화율은 79.2%와 79.8%이었고, 알 기간은 3.0일과 2.9일이었는데, 사료 사이에 유의한 차이는 없었다.
Two meridic diets, N4 and N6, containing pinto bean, wheat germ, soybean, whole milk and sucrose as main nutrients were developed for rearing Spodoptera frugiperda (Noctuidae) larvae. Six larval instars were observed when neonate larvae were individually raised on these diets in small petri-dishes (ø 50 × 10 mm, 19.6 cm3) at 25oC and 15:9 h (light:dark) photoperiod. The average pupation rate of 97.8% on the N4 diet was significantly higher than the rate of 85.6% on N6 diet. The emergence rates were 92.0% on N4 diet and 93.5% on N6 diet, with a non-significant difference. The larval periods were 17.9 and 17.7 days for females, and 18.7 and 18.5 days for males, for N4 and N6 diets, respectively, with non-significant differences between diets and sexes. The pupal periods on both diets were identical (11.1 days for females and 12.8 days for males), despite differences between sexes. The pupal weights of both sexes on N4 diet were identical with a value of 257 mg, whereas those on N6 diet were 256 and 263 mg for females and males, respectively, with a non-significant difference. The longevity of female adults that emerged on N6 diet was 13.8 days and longer than 8.6 days on N4 diet. The pre-oviposition periods were 5.0 and 4.2 days on the N4 and N6 diets, respectively, with a non-significant difference, however, the oviposition period of 6.5 days on N6 diet was longer than the period of 3.9 days on N4 diet. The effective fecundity on N6 diet was 1,392 eggs (maximum 1,776) and was higher than that of 942 eggs (maximum 1,694) on N4 diet, with a non-significant difference. The egg hatching rates on N4 and N6 diets were 79.2 and 79.8%, and egg periods were 3.0 and 2.9 days, respectively, with non-significant differences.
Dioscin (DS) is a steroidal saponin present in a number of medicinal plants and has been shown to exert anticancer, antifungal and antiviral effects. The present study aimed to deternube the effects ...DS on the regulation of adipogenesis and to elucidate the underlying mechanisms. In vitro experiments were performed using differentiating 3T3-L1 cells treated with various concentrations (0-4 µM) of DS for 6 days. A cell viability assay was performed on differentiating cells following exposure to DS. Oil Red O staining and triglyceride content assay were performed to evaluate the lipid accumulation in the cells. We also carried out the following experiments: i) flow cytometry for cell cycle analysis, ii) quantitative reverse transcription polymerase chain reaction for measuring adipogenesis-related gene expression, and iii) western blot analysis to measure the expression of adipogenesis transcription factors and AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC) and mitogen-activated protein kinase (MAPK) phosphorylation. In vivo experiements were performed using mice with obesity induced by a high-fat diet (HFD) that were treated with or without DS for 7 weeks. DS suppressed lipid accumulation in the 3T3-L1 cells without affecting viability at a dose of up to 4 µM. It also delayed cell cycle progression 48 h after the initiation of adipogenesis. DS inhibited adipocyte differentiation by the downregulation of adipogenic transcription factors and attenuated the expression of adipogenesis-associated genes. In addition, it enhanced the phosphorylation of AMPK and its target molecule, ACC, during the differentiation of the cells. Moreover, the inhibition of adipogenesis by DS was mediated through the suppression of the phosphorylation of MAPKs, such as extracellular-regulated kinase 1/2 (ERK1/2) and p38, but not c-Jun-N-terminal kinase (JNK). DS significantly reduced weight gain in the mice with HFD-induced obesity; this was evident by the suppression of fat accumulation in the abdomen. the present study reveals an anti-adipogenic effect of DS in vitro and in vivo and highlights AMPK/MAPK signaling as targets for DS during adipogenesis.
Etanercept is a widespread biological drug for the treatment of rheumatoid arthritis, which inhibits tumor necrosis factor-α (TNF-α). Recently, the presence of antibodies targeting TNF-α inhibitors ...such as infliximab and adalimumab, was reported. However, few reports have studied etanercept in a mouse model of arthritis. We investigated the induction of anti-etanercept antibody production, along with the antibody's potential interfering effects on the biological function of etanercept, in mice with collagen-induced arthritis (CIA). CIA mice received an intraperitoneal injection of etanercept (25, 100 or 400 µg per mouse). The degree of inflammation and cartilage erosion was evaluated, and the number of osteoclasts in the ankle joints was assessed by TRAP staining. The level of pro-inflammatory cytokines in the serum was measured. To analyze the anti-osteoporotic effect of etanercept, microfocal computed tomography analyses of femurs and tibias were performed. Etanercept treatment decreased both the incidence and severity of arthritis in a dose-dependent manner, except for the highest dose of 400 µg. The mice that were treated with 25 and 100 µg etanercept showed an improvement in inflammation, cartilage damage, and even bone loss. However, mice treated with 400 µg etanercept showed no significant improvement in any of the tested parameters. Using a customized enzyme-linked immunosorbent assay (ELISA), the presence of the anti-etanercept antibody was detected in the serum in this treatment-refractory group. The therapeutic effect of etanercept was reduced in the CIA mice that developed the anti-etanercept antibody. In conclusion, the production of an anti-etanercept antibody can be induced in CIA mice, and this antibody can considerably reduce the anti-arthritic and anti-osteoporotic effects of etanercept.
The zero-truncated Poisson distributions are certain discrete probability distributions whose supports are the set of positive integers, which are also known as the conditional Poisson distributions ...or the positive Poisson distributions. Recently, as a natural extension of those distributions, Kim–Kim studied the zero-truncated degenerate Poisson distributions. In this paper, we introduce the
r
-truncated degenerate Poisson random variable with parameter
α
>
0
, whose probability mass function is given by
p
λ
,
r
(
i
)
=
(
1
)
i
,
λ
e
λ
(
α
)
−
e
λ
,
r
(
α
)
α
i
i
!
,
(
i
=
r
+
1
,
r
+
2
,
r
+
3
,
…
)
, and investigate various properties of this random variable.