• 농업과학연구
• /
• 제46권1호
• /
• pp.113-124
• /
• 2019

Insect-resistant transgenic (Bt-9) rice was generated by inserting mCry1Ac1, a modified gene from the soil bacterium Bacillus thuringiensis, into the genome of a conventional variety of rice (Ilmi). With regard to potential problems such as safety, an evaluation of non-target organisms is necessary as an essential element of an environmental risk assessment of genetically modified (GM) crops. We studied the effects of the Bt-9 rice on the survival of cantor Daphnia magna, a commonly used model organism in ecotoxicological studies. D. magna fed on the Bt-transgenic rice (Bt-9) and its near non-GM counterparts (Ilmi) grown in the same environment (a 100% ground rice suspension). The Bt-9 rice was confirmed to have the inserted T-DNA and protein expression evident by the PCR and ELISA analyses. The feeding study showed a similar cumulative immobility and abnormal response of the Daphnia magna between the Bt-9 rice and Ilmi. Additionally, the 48 h-EC50 values of the Bt-9 and Ilmi rice were 4,400 mg/L (95% confidence limits: 3861.01 - 5015.01 mg/L) and 5,564 mg/L (95% confidence limits: 4780.03 - 6476.93 mg/L), respectively. The rice NOEC (No observed effect concentration) value for D. magna was suggested to be 1,620 mg/L. We conclude that the tested Bt-9 and Ilmi have a similar cumulative immobility for D. magna, a widely used model organism, and the growth of Bt-9 did not affect non-target insects.

• Environmental Analysis Health and Toxicology
• /
• 제13권3_4호
• /
• pp.55-61
• /
• 1998

Glutathione-S-transferases (GSTs) detoxify electrophilic xenobiotics and reactive metabolites. Recently benzene-fused heterocycles have been shown to increase the total amount of hepatic GSTs in rats. Primarily this study aimed to determine the induction of GSTs by benzoazoles (BAs) including benzoxazole (BX), 2-methylbenzoxazole (M-BX), 2,5-dimethyl benzoxazole (D-BX), benzothiazole (BT), aminobenzothiazole (A-BT) and 2-mercaptobenzothiazole (M-BT) in rats. Hepatic cytosol and poly(A)$^+$ mRNA were prepared from rats after oral administration of BX, BT, M-BX, D-BX, A-BT and M-BT for 5 consecutive days at doses of 1 mmol/kg. Western immunoblot and northern blot analysis were conducted with rabbit anti-GST Ya, Yb$_1$, Yb$_2$, Yc antibodies and cDNA probes containing = 500 bps in the specific coding regions of Ya, Yb$_1$, Yb$_2$, Yc$_1$, and Yc$_2$, respectively. All BAs increased the amount of enzymes and mRNA levels of GSTs. BT was the most effective inducer of GSTs among the compounds examined in this study. Although A-BT and M-BT, the derivatives of BT, induced GSTs, these chemicals had lesser effect on induction of GSTs than BT. The derivatives of BX also induced less GSTs than the parent compound and the addition of methyl group to the benzene ring of BX reduced the induction of GSTs. BAs had better inductive effects on the class $\alpha$(Ya, Yc) than class $\mu$ GSTs (Yb$_1$, Yb$_2$). BAs enhanced mRNA levels of GSTs in parallel with the protein levels. These results indicate that 1) most of BAs induced various isozymes of GSTs, 2) the induction of GSTs appears to be correlated with the chemical structure of the derivatives, and 3) the expression of GST by BAs is presumably under the transcriptional regulation.

• Biomolecules & Therapeutics
• /
• 제30권3호
• /
• pp.246-256
• /
• 2022

The present study focused on the potential mechanism of betulin (BT), a pentacyclic triterpenoid isolated from the bark of white birch (Betula pubescens), against chronic alcohol-induced lipid accumulation and metaflammation. AML-12 and RAW 264.7 cells were administered ethanol (EtOH), lipopolysaccharide (LPS) or BT. Male C57BL/6 mice were fed Lieber-DeCarli liquid diets containing 5% EtOH for 4 weeks, followed by single EtOH gavage on the last day and simultaneous treatment with BT (20 or 50 mg/kg) by oral gavage once per day. In vitro, MTT showed that 0-25 mM EtOH and 0-25 µM BT had no toxic effect on AML-12 cells. BT could regulate sterolregulatory-element-binding protein 1 (SREBP1), lipin1/2, P2X7 receptor (P2X7r) and NOD-like receptor family, pyrin domains-containing protein 3 (NLRP3) expressions again EtOH-stimulation. Oil Red O staining also indicated that BT significantly reduced lipid accumulation in EtOH-stimulated AML-12 cells. Lipin1/2 deficiency indicated that BT might mediate lipin1/2 to regulate SREBP1 and P2X7r expression and further alleviate lipid accumulation and inflammation. In vivo, BT significantly alleviated histopathological changes, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and triglyceride (TG) levels, and regulated lipin1/2, SREBP1, peroxisome proliferator activated receptor α/γ (PPARα/γ) and PGC-1α expression compared with the EtOH group. BT reduced the secretion of inflammatory factors and blocked the P2X7r-NLRP3 signaling pathway. Collectively, BT attenuated lipid accumulation and metaflammation by regulating the lipin1/2-mediated P2X7r signaling pathway.

• 대한바이러스학회지
• /
• 제29권3호
• /
• pp.145-153
• /
• 1999

We have now constructed a novel recombinant baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV) producing polyhedra with Bacillus thuringiensis (Bt) CryIAc crystal protein. The recombinant polyhedra produced by the recombinant baculovirus, Btrus, in insect cells was characterized. The recombinant baculovirus has two independent transcription units in opposite orientations with two promoters, p10 or polyhedrin gene promoter each initiating transcription of either native polyhedrin or fusion protein with polyhedrin and Bt Cry1Ac crystal protein. Surprisingly, this recombinant baculovirus stably produced recombinant polyhedra which were nearly similar to those of wild-type AcNPV. The immunogold staining experiment showed that the recombinant polyhedra were assembled with polyhedrin and Bt Cry1Ac crystal protein, and contained virus particles. Insecticidal toxicity of recombinant polyhedra of Btrus to the fall webworm, Hyphantria cunea, was strikingly improved in comparison with the wild-type AcNPV.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제14권1호
• /
• pp.33-36
• /
• 2007

To improve insecticidal activity of B. thuringiensis 2385-1 (Bt 2385-1), a recombinant plasmid, pHT1K-1Ac, was introduced into lepidopteran toxic Bt 2385-1 by electroporation. The presence of the recombinant plasmid in Bt 2385-1 after electroporation was confirmed by PCR. Bt 2385-1 transformant was named as Bt pHT1K-1Ac/2385-1 (1K-1Ac/2385-1). The 1K-1Ac/2385-1 transformant produced bipyramidal-shaped parasporal inclusion as like the wild-type strain, Bt 2385-1, and showed an 130 kDa band of Cry1Ac protein. The insecticidal activity of 1K-lAc/2385-1 against S. exigua was similar to that of Bt 2385-1 but the $LC_{50}$ value of transformant against P. xylostella was 1.8 times lower. Through these bioassay results, it was confirmed that toxicity of Bt 2385-1 transformant showed synergistic effect by introducing Cry1Ac. These results suggested that the multiple expressions of Cry proteins in a promising Bt strain may interact synergistically in insect midgut, resulting in increase of toxicity and expansion of host spectrum.

• Applied Biological Chemistry
• /
• 제35권4호
• /
• pp.227-231
• /
• 1992

식물병원성 사상균에 대해 길항력을 갖는 그람음성 Pseudomonas fluorescens KR164의 chromosome에 그람 양성인 Bacillus thuringiensis(BT)의 HD-1 toxin gene을 삽입하기 위하여 이 유전자를 갖는 plasmids pSUPBT과 pSUPBTR을 작성하였다. Conjugation을 이용한 transposition으로 P. fluorescens KR164의 chromosome에 이 plasmids를 삽입시켜 BT toxin 유전자를 갖는 P. fluorescens KR164의 변이균주를 조제하였다. Southern blotting으로 균주의 cellular DNAs를 조사한 결과 모든 변이균주에서 한 개 이상의 BT toxin gene의 삽입이 확인 되었으며 독소단백질의 존재 역시 SDS-PAGE에 의해서 확인되었으며 이러한 독소단백질의 결정 생성은 전자현미경에서도 확인되었다.

• 한국양식학회지
• /
• 제11권3호
• /
• pp.381-390
• /
• 1998

참전복 치패용 배합사료의 적정 지질원을 조사하기 위하여 카제인과 북양어분을 각각 단백질원으로 하고 지방산과 지질원을 달리 첨가하여 3회에 걸쳐 사육실험을 실시하였다. 세 실험 모두 평균체중 160mg의 치패를 각 수조에 100마리씩 수용하여 사료마다 3반복으로 20주간 사육 실험하였다. 1. 카제인 사료에 지방산 첨가 효과, 단백질원을 카제인으로 하여 지방산이 달리 첨가된 6종의 사료(지방산 무첨가구, 12 :0, 18 : 1, 18 : 2, 18 : 3 및 n-3HUFA첨가구)로 사육실험한 결과, 생존율, 최종 평균체중, 증체율 및 가식부 중량도 사료의 지방산에 영향을 받지 않았다 (P>0.05). 반면에 평균 각장은 지방산 무첨가구(fat-free)와 n-3HUFA첨가구가 가장 낮아서 18 : 1과 18 : 2 첨가구와 유의차를 보였다(P<0.05). 가식부의 수분과 단백질 함량은 실험구간에 차이가 없었으며(p>0.05), 지질은 지방산 무첨가구가 0.5%로 18 : 1 첨가구의 0.7%와 유의한 차이를 보였다(P<0.05). 2. 카제인 사료에 지질원 첨가 효과 단백질원을 카제인으로 하여 오징어 간유(SO), 옥수수유(CO), 우지(BT), SO+CO및 SO+BT를 각각 5%씩 첨가한 배합사료로 사육 실험한 결과, 생존율은 실험구간에 유의한 차이는 없었으나(P>0.05), 최종평균체중, 증체율 및 각장은 SO, SO+CO 및 SO+BT(n-3HUFA 함량: 0.5%) 실험구가 CO및 BT 실험구가 높은 값을 나타내었다(P<0.05). 가식부 평균중량도 SO+CO 및SO+BT 실험구는 SO 실험구와 유의차없이 좋은 결과를 보였지만, CO및 BT가 실험구는 SO 실험구보다 유의하게 낮은 값을 보였다(P<0.05). 실험 종료시 가식부의 수분과 단백질 함량은 사료의 지질원에 영향을 받지 않았지만, 지질함량은 SO가 첨가된 실험구(SO, SO+CO, SO+BT)가 CO첨가구보다 유의하게 높은 값을 보였다(p<0.05). 3.어분 사료에 지질원 첨가 효과 실용적인 측면을 고려하여 단백질원으로 어분이 첨가된 사료에 지질은 첨가하지 않은 사료와 SO, CO, BT, SO+CO 및 SO+BT을 각각 5% 첨가한 사료로 사육한 결과, 생존율은 실험구가에 유의차가 없었으나(P>0.05), 증체율은 BT와 SO+BT 실험구가 지질 무첨가구 (지질함량 : 2.2%), SO 및 CO 실험구보다 유의하게 낮았다(P<0.05). 실험종료시 가식부의 수분과 단백질 함량은 사료 지질에 영향을 받지 않았지만, 지질은 사료 지질 함량과 지질원에 영향을 받아 지질 무첨가구가 가장 낮았다(P<0.05). 이사의 결과들로부터 참전복 치패용 배합사료에는 n-3HUFA가 0.5%이상 함유되어야 할 것으로 생각되며, 어분이 첨가된 사료에 지질이 2%이상일 때는 지질을 추가로 첨가할 필요는 없으며, 지질을 추가할 경우 우지보다는 어유나 식물성기름을 첨가하는 것이 바람직할 것으로 기대된다.

• 한국잠사곤충학회지
• /
• 제37권1호
• /
• pp.68-73
• /
• 1995

미국흰불나방(Hyphantria cunea)의 유충에서 중장, 지방체, 말피기씨관에 Bacillus thuringiensis(Bt) var. kurstaki의 내독소 단백질의 독성효과로 인한 생리적 변화를 autoradiography와 Western blot으로 확인하였다. 단백질 합성과 번역연장민자-2에 미치는 영향을 조사한 결과, 앞의 모든 조직에서 단백질 합성이 급격히 저하되었으며, 번역연자인자-2의 활성도 병행하여 저하되었다.

• 한국생물공학회소식지
• /
• 제15권2호
• /
• pp.12-18
• /
• 2008

• 한국생물공학회소식지
• /
• 제18권1호
• /
• pp.80-81
• /
• 2011