플라스틱은 전세계적으로 사용량이 증가함에 따라 해양 환경으로 유입되는 플라스틱 쓰레기의 양도 꾸준히 증가하고 있으며, 미세플라스틱은 해양 생물에 의해 섭취되어 소화관에 축적됨에 따라 성장과 생식에 유해한 영향을 미친다. Cytochrome P450 (CYP)는 환경 오염물질을 대사하 는 해독효소로 알려져 있으나 지각류에서는 그 기능에 대해서는 잘 알려져 있지 않다. 본 연 구에서는 기수산 물벼룩 Diaphanosoma celebensis에서 clan 2, 3, 4에 각각 속하는 CYP 유전자 9종(clan 2: CYP370A4, CYP370C5; clan 3: CYP350A1, CYP350C5, CYP361A1; clan 4: CYP4AN-like, CYP4AP2, CYP4AP3, CYP4C33-like1)의 서열에 대해 진화적으로 보존된 서열의 유사도를 분석 하고 계통분석을 실시하였다. 또한 3종류의 서로 다른 크기의 polystyrene beads (0.05-, 0.5-, 6-μm PS beads; 0.1, 1, and 10 mg/L)에 48시간 노출된 기수산 물벼룩에서 이들 9종의 CYP 유 전자의 발현을 real time reverse transcription polymerase chain reaction (RT-PCR)로 분석하였 다. 결과적으로 기수산 물벼룩 CYP 유전자는 모두 진화적으로 보존된 motif를 가지고 있으며 계통분석 결과 각각 clan 2, 3, 4에 속하는 것으로 확인되었다. 이는 기능적으로 보존되어 있음 을 의미한다. CYP 유전자 중 clan 2에 속하는 CYP370C5와 clan 3에 속하는 CYP360A1, 그리고 clan 4에서는 CYP4C122 유전자의 발현이 0.05-μm PS beads에 노출되었을 때 유의하게 증가 하는 양상을 보였으며, 이는 이들 유전자가 PS 대사에 관여한다는 것을 의미한다. 본 연구는 미세플라스틱이 해양 무척추 동물에 미치는 생물 영향을 분자적 수준에서 이해하는데 도움이 될 것이다.

In Korea, the Asian honey bee (Apis cerana) and the European honey bee (Apis mellifera) (Hymenoptera: Apidae) are the two most common honey bee species. These two closely related species are known to have different sensitivity levels to various insecticides due to millennia of exposure to different pests and pesticides. It is reported that A. cerana is known to be more sensitive to several insecticides, such as amitraz, fenitrothion, and fipronil, than A. melllifera. Multiple studies investigated toxicological responses and related CYPome in A. mellifera, but little is known in A. cerana. The goal of this study is to elucidate the underlying mechanism of different toxicological responses between two bee species, with an emphasis on cytochrome P450 (P450), a significant enzyme involved in metabolic activities. The differences in basal P450 expression patterns were investigated by comparing the relative expression levels of P450 orthologs in several dissected organisms of each species. To compare the sensitivity against major insecticides, lethal doses of major insecticides relevant to both honey bee species were assessed by topical and oral ingestion bioassays. The determined sublethal doses of insecticides were applied to honey bees, and the inducibility of P450s was investigated by comparing the expression patterns of multiple P450s. From these results, this study eventually attempts to compare the toxicological differences between two Apis species with differences in induced cytochrome P450 expression levels.

The Varroa mite, Varroa destructor, a parasitic mite that afflicts honey bees, has become increasingly resistant to acaricides like fluvalinate due to its widespread use. The target site insensitivity mechanism, mediated by the L925V/M/I mutations in the voltage-gated sodium channel, plays a major role in resistance. Additionally, cytochrome P450 monooxygenases (Cyp450s) appear to function as a metabolic resistance factor; however, no Cyp450-mediated resistance mechanism has been reported to date. The aim of this study was to identify and characterize Cyp450s associated with fluvalinate resistance. A synergistic bioassay confirmed the involvement of Cyp450s in conferring tolerance or resistance to fluvalinate. Correlation analysis between mortality data and the expression levels of Cyp450 genes led to the identification of several candidates that may play a crucial role in fluvalinate resistance. Analysis of tissue distribution patterns revealed that these genes were most abundantly expressed in the cuticle and synganglion. This suggests that, despite their relatively low expression level, they may play a critical role in protecting the target site from fluvalinate due to its predominant expression in neuronal tissues. Functional analysis, in conjunction with baculovirus expression, demonstrated that fluvalinate has high inhibition rates against the recombinant candidate Cyp450s, suggestive of their strong interaction with fluvalinate. We discussed the potential utilization of their expression levels as a molecular marker for diagnosing metabolic resistance in field-collected Varroa mites.

1,2-Dichlorobenzene (1,2-DCB) is in various industries as solvents in herbicides, pesticides, and wax, and as degreasers or in the production of dyes. Studies on the hazards and risks of 1,2-DCB showed that this substance can cause skin corrosion, skin irritability, respiratory irritability, and certain target organ toxicity. Industrial workers are exposed to 1,2-DCB by inhalation or skin exposure and there is a lack of information on human hazards even though they can be exposed to organic compounds such as benzene or other DCB complexes rather than a single substance. In this study, we investigated the specific organ toxicity of 1,2- DCB and sex differences using whole-body inhalation in laboratory mice. Male and female mice were exposed to 0–120 ppm of the test substance for 13 weeks. After euthanization, the organs were collected, histopathological assessments and immunohistochemistry (IHC) were performed, and lipid peroxidation was analyzed. Macro and microscopic lesions were observed in the livers of male mice exposed to the test substance, and microscopic alterations were observed in the nasal cavities of male and female mice. IHC analysis of the liver confirmed a greater increase in cytochrome P450 induction in males than in female mice, and malondialdehyde and 4-hydroxynonenal were increased in both sexes by 1,2-DCB inhalation. Based on the relevant literature and experimental results, 1,2-DCB is believed to cause specific organ toxicity in the livers of male mice and the nasal cavities of both sexes of mice, which is supposed to be related to sex differences in cytochrome P450 induction and changes in lipid and oxidative products associated with the early metabolites of the test substance.

Under the stressed condition, a complex feedback mechanism for stress is activated to maintain homeostasis of the body and secretes several stress hormones. But these stress hormones impair synthesis and secretion of the reproductive hormones, followed by suppression of ovarian function. Cytochrome P450 1A2 (CYP1A2) plays a major role in metabolizing exogenous substances and endogenous hormones, and its expression is recently identified at not only the liver but also several organs with respect to the pancreas, lung and ovary. Although the expression of CYP1A2 can be also affected by several factors, understanding for the changed pattern of the ovarian CYP1A2 expression upon stress induction is still limited. Therefore, CYP1A2 expression in the ovaries from immobilization stress-induced rats were assessed in the present study. The stress-induced rats in the present study exhibited the physiological changes in terms of increased stress hormone level and decreased body weight gains. Under immunohistological observation, the ovarian CYP1A2 expression in both control and the stressed ovary was localized in the antral to pre-ovulatory follicles. However, its expression level was significantly (p < 0.01) higher in the stress-induced group than control group. In addition, stress-induced group presented more abundant CYP1A2-positive follicles (%) than control group. Since expression of the ovarian CYP1A2 was highly related with follicle atresia, increased expression of CYP1A2 in the stressed ovary might be associated with changes of the ovarian follicular dynamics due to stress induction. We hope that these findings have important implications in the fields of the reproductive biology.

Cytochrome P450 1A2 (CYP1A2) is a member of the cytochrome P450 superfamily enzymes in mammals and plays a major role in metabolizing endogenous hormones in the liver. In recent days, CYP1A2 expression has been found in not only the liver but also other tissues including the pancreas and lung. However, little information is available regarding the expression of CYP1A2 in the ovary, in spite of the facts that the ovarian follicle growth and atresia are tightly associated with controls of endocrine hormonal networks. Therefore, the expression of CYP1A2 in the ovaries of prepubertal and pubertal rats was investigated to assess its expression pattern and puberty-related alteration. It was demonstrated that the expression level of CYP1A2 was significantly (p < 0.01) higher in the pubertal ovaries than prepubertal counterparts. At the ovarian follicle level in both groups, whereas CYP1A2 expression was less detectable in the primordial, primary and secondary follicles, the strongly positive expression of CYP1A2 was localized in the granulosa cell layers in the antral and pre-ovulatory follicles. However, the ratio of CYP1A2-positive ovarian follicle was significantly (p < 0.01) higher in the ovary of pubertal group (73.1 ± 3.1%) than prepubertal one (41.0 ± 10.5%). During the Immunofluorescence, expression of CYP1A2 was mainly localized in Fas-positive follicles, indicating the atretic follicles. In conclusion, these results suggested that CYP1A2 expression was mainly localized at the atretic follicular cells and affected by the onset of puberty. Further study is still necessary but we hypothesize that CYP1A2 expresses in the atretic follicles to metabolize residue of the reproductive hormones. These findings may have important implications for the fields of reproductive biology of animals.

Cytochrome P450s (P450s) are known to oxidize a variety of insecticides including pyrethroids, thereby conferring metabolic resistance in diamondback moth (DBM), Plutella xylostella. Synergism assay with piperonyl butoxide indicated that the enhanced activity of P450 is associated with pyrethroid resistance in a cypermethrin-resistant (CR) strain. However, there were little differences in the basal transcription levels of all the P450s examined between susceptible (Sus) and CR strains, suggesting that constitutive overexpression of P450 is not likely involved in the cypermethrin resistance but induction of P450 by cypermethrin is rather associated with metabolic resistance. To determine the conditions resulting in maximum levels of P450 induction, several factors including the way of adminstration (topical application vs. leaf dipping), exposure dose and exposure duration were examined. In general, leaf dipping method resulted in greater levels of induction in a wider array of P450s. The conditions of ‘low dose (sublethal dose or concentration) and short exposure (less than 3 hr)' to cypermethrin were more efficient in P450 induction than those of ‘high dose (around LD50 or LC50) and long exposure (more than overnight)’, which have been employed in many other studies to date. Cross-strain comparison revealed that 9 of 11 P450s were induced 1.4-2.2 fold in CR whereas only 3 P450s in Sus under the optimal induction conditions, demonstrating that metabolic resistance in CR strain is actually conferred by the mechanism of selective P450 induction when exposed to cypermethrin.

비이온성 계면활성제로 많이 쓰이는 알킬페놀류의 하나인 노닐페놀(nonylphenol)이 해산어류에게 미치는 영향을 조사하려고 주요 양식어종인 조피볼락에게 복강주사로 10 및 25 mg kg-1을 1회 투여하였다. 한편 용제인 DMSO만을 주사한 sham구를 설정하여 비교하였다. 주사 후 7일간 간중량지수(hepatosomatic index)의 변화를 조사하였고, 또한 간장 미크로좀 중 대표적인 약물대사효소인 cytochrome P450 (CYP

내분비계 장애물질이 해양생물에게 미치는 영향을 조사하기 위한 연구의 일환으로 우리나라 연안떼서 보편적으로 분포하는 p,p'-DDT, 2, 3, 7, 8-TCDD및 PCB-153을 대상으로 이들 화합물이 동해안산 명주조개의 미크로좀 중 약물대사 효소계에 미치는 형향을 살펴보았다. 명주조개의 중장선으로 만든 미크로좀에 상기한 화합물을 DMSO에 녹여 일정한 농토가 되도록 첨가하고 p,p'-DDT (0.1, 0.4 및 1.0 mM)는 30분까지 그리고 2,

해산 어류가 cyochrome P450(CYP)유도제로 알려진 eta-naphthoflavone(BNF)에 의해 어떤 반응을 하는지 살펴보기 위하여, 양식 어류로는 조피볼락(Sebastes schlegeli), 넙치 (Paralichthys olivaceus), 참돔(Pagrus major)을 그리고 자연산 어류로는 숭어(Mugil cephalus)와 쥐치 (Stephanolepis cirrhifer)를 대상으로 조사하였다. 숭어와 쥐치, 참돔의