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        검색결과 29

        1.
        2023.10 구독 인증기관·개인회원 무료
        The rate of resistant pest emergence has accelerated due to the continuous use of pesticides. Therefore, it is important to formulate insecticide resistance management measures and effective control methods for pest. Bemisia tabaci, a greenhouse pest, causes direct damage to crops such as growth inhibition and leaf discoloration at all developmental stages except for eggs. It also indirectly damages plants by secreting honeydew, which covers surrounding leaves and fruits, leading to sooty mold development. In this study, eight insecticides with high usage rates, categorized by their mode of action, were selected. Samples of Bemisia tabaci were collected from six regions, and resistance analysis were conducted. The results showed that Flonicamid exhibited a resistance ratio of 8.91 in Sejong, while Pyriproxyfen showed a high resistance ratio of 63.56 in Gunwi. Fluxametamide, Spinetoram, Cyantraniliprole, Dinotefuran, Pyridaben, and Milbemectin displayed resistance ratio ranging from 0.02 to 1.14 in most regions, except for Flonicamid and Pyriproxyfen.
        10.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Interferon-tau (IFNT) is known as a major conceptus protein that signals the process of maternal recognition of pregnancy in ruminants. Also, multiple interferon genes exist in cattle, However, molecular mechanisms of these bovine IFNT (bIFNT) genes whose expressions are limited have not been characterized. We and others have observed that expression levels of bovine subtype IFNT genes in the tissues of ruminants; thus, bIFNT1 and other new type I (bIFNTc1/c2/c3) gene co-exist during the early stages of conceptus development and non-trophoblast cells. Its genes transcription could be regulated through CDX2 and ETS2 and JUN and/or cAMP-response element binding protein (CREB)-binding protein (CREBBP) expression, a transcription factor implicated in the control of cell differentiation in the trophectoderm. Bovine ear-derived fibroblast cells, were co-transfected with luciferase reporter constructs carrying upstream (positions -1000 to +51) regions of bIFNT1 and other new type I gene and various transcription factor expression plasmids. Compared to each - 1kb-bIFNT1/ c1/c2/c3-Luc increased when this constructs were co-transfected with CDX2, ETS2, JUN and/or CREBBP. Also, Its genes was had very effect on activity by CDX2, either alone or with the other transcription factors, markedly increased luciferase activity. However, the degree of transcriptional activation of the bIFNTc1 gene was not similar to that bIFNT1/c2/c3 gene by expression plasmid. Furthermore, Sequence analyses also revealed that the expression levels of bIFNT1/c2/c3 gene mRNAs expression were highest on day 17, 20 and 22 trophoblast and, Madin-Darby bovine kidney (MDBK), Bovine ear-derived fibroblast (EF), and endometrium (Endo) non-trophoblast cells. But, bIFNTc1 mRNA had not same expression level, bIFNTc1 lowest levels than those of IFNT1/c2/c3 gene in both trophoblast and non-trophoblast cells. These results demonstrate that bovine subtype bIFNT genes display differential, in the trophoblast and non-trophoblast cells.
        4,000원
        11.
        2018.11 구독 인증기관·개인회원 무료
        Variance of conceptus interferon tau (IFNT), produced by the embryonic trophectoderm, is known as a major conceptus protein that signals the process of maternal recognition of pregnancy in ruminants, essential for the maintenance of early pregnancy. Similar to other IFN genes such as IFNA and IFNB, multiple IFNT genes are present. However, some kinds of IFNT genes actively transcribed and regulated in bovine conceptuses have not been well characterized. In this study, during the course of bovine IFNT gene transcription through the use of next generation sequencer SOLiD3, revealed that among 38 IFN genes registered, only two transcripts, IFNT1 and IFNTc1, were found in conceptuses during early pregnancy. Also, to identify a transcription factor(s) involved in the regulation of IFNT genes, mRNAs for various known transcription factors were investigated by real-time PCR in conceptus tissues, respectively. Furthermore, compared to the IFNT genes, IFNT1 and IFNTc1 had same active levels, which were previously shown to correlate with the appearance of effective antiviral activity. However, the expression levels of these Luc activities differed. Bovine ear fibroblast (EF) cells were cotransfected with luciferase reporter constructs carrying upstream (–631 to -51) promoter regions of IFNT1 or IFNTc1 and various transcription factor expression plasmids, CDX2, AP1(JUN), ETS2 and/or cAMP-response element binding protein (CREB)-binding protein (CREBBP). CDX2, either alone with the other 2 transcription factors, was found to increase luciferase activity approximately 14- and 11-folds, respectively. The degree of transcriptional activation of the IFNTc1 gene was not similar to that IFNT1 gene by AP1, ETS2 or/and CREBBP, expression plasmid. These results suggest that two isoforms of bovine conceptus IFNT genes are regulated differently in conceptuses during early pregnancy.
        12.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to evaluate the effect of treating dairy cattle with exogenous human chorionic gonadotrophin (hCG), five (5) days post artificial insemination (AI) on serum progesterone (P4) concentration and pregnancy rate. In this experiment, five days after AI, cows were assigned randomly to two groups namely: a) treated group (67) which were administrered with 1500 IU hCG (Chorulon) and b) control group (61), which received no treatment. On day 5, 10, 15 and 20 after the artificial insemination, blood samples from a total of 8 cows (4 from each group) were collected and were analyzed for serum P4 concentration. Cows were detected for estrus according to standing heat by visual observation. Cows that were detected still in estrus after days 18-24 were re-inseminated and recorded as not pregnant (open). Pregnancy diagnosis was conducted by ultrasonographic examination and transrectal palpation of the uterus on approximately 60 days in cows that observed to be not in estrus. The conception rate in hCG treated and control groups were 52.5 and 36.1%, respectively. The results proved that there were no significant differences in conception rate between two groups (p=0.0568). However, pregnancy rates were reduced by hCG treatment. Average serum P4 concentrations did not differ between Hcg-treated and control groups on day 5 (0.377 versus 0.375 ng/ml). On day 20 serum P4 concentrations were greater in the treated group compared with the control group (3.085 versus 2.010 ng/ml). The treatment with hCG seemed to increase P4 level compared with the control. In conclusion, the results of this study showed that 1500 IU of hCG administered on 5 day post AI increased conception rate in dairy cows. This was supported by the results on serum P4 concentration which was greater in hCG treated group.
        4,000원
        13.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 분만간격에 따른 추가 착유일수를 계산하여 불완전 Gamma모형으로 추정된 비유곡 선모수값을 통하여 추가 착유일 만큼의 산유량을 계산하고, 추가 착유에 따른 경제성을 분석하기 위함 이다. 경제성 분석을 위하여 농협중앙회 젖소개량사업소에서 진행하고 있는 유우군 능력검정사업에 참 여하고 있는 홀스타인 젖소로부터 조사한 착유기록 2,072개를 분석하였는데, 분석에 이용된 착유기록은 2010년 1월부터 2012년 12월 사이에 분만한 초산우 및 경산우로부터 자료이다. 비유곡선 모수는 Wood 모형을 적용하여, SAS 9.2 NLIN Procedure를 이용해 추정하였다. Wood 모형으로 추정한 비유곡선 함수는 초산우 및 경산우에 대해 각각 yt = 18.00t0.189e-0.00231t 및 yt = 24.73t0.181e-0.00315t로 추정되었다. 초산 우의 경우 산유량이 8,000kg 이하인 우군의 적정 분만간격은 400일 이하로 유지하는 것이 바람직하며, 8,000kg 이상인 우군은 분만간격을 400일에서 500일 사이로 유지하는 것이 바람직하다. 경산우의 경 우 산유량이 9,000kg 우군은 적정 분만간격을 400일 이하로 유지하고, 9,000kg 이상인 우군의 분만간 격은 400일에서 500일 사이로 유지하는 것이 바람직하겠으며, 11,000kg 이상의 고능력 경산우 우군의 경우 분만간격이 길어질수록 순수이익은 증가하나, 차기 임신 및 분만을 위해서는 분만간격을 450일에 서 500일 사이로 유지하는 것이 바람직하다고 할 수 있겠다.
        4,200원
        14.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        두 개의 형질 사이에 유전상관이 존재하면 제 1의 형질을 선발함으로써 다른 중요한 형질의 간접선발도 가능해 진다. 따라서 부분육 형질 중 선호도가 높은 안심과 등심에 대한 생산량 증대를 위해서 생체 상태에서 부분육과 상관도가 높은 체형형질을 발굴하여 개량함으로써 고가이며 선호도가 높은 안심과 등심 등의 생산량을 높일 수 있을 것이라 사료된다. 분석에 이용한 데이터는 1998~2012년도에(23~53차) 후대검정한 5,001두의 후대검정우 자료이며 조사형질로는 대분할육 10개의 형질과 18개월령 체형형질을 이용하였다. 유전모수 추정은 WOMBAT 6.0 software package를 이용하여 실시하였다. 분석에 이용된 모형은 부분육 중량의 경우 도축일을 범주형 변량으로 도축 전 생체중을 공변량으로 하였으며 체형형질의 경우에는 차수, 출생지 및 검정소를 범주형 변량으로 측정일령을 공변량으로 하였다. 분석 결과 안심, 등심 및 갈비중량의 유전력은 각각 0.53, 0.50 및 0.14로 나타났다. 등심과 안심은 체고, 십자부고 및 곤폭과 유전상관이(0.34~0.53) 비교적 높게 나타났으므로 이러한 체형형질을 간접선발 함으로써 선호되는 부위의 생산량을 늘릴 수 있을 것이라 사료된다.
        4,000원
        15.
        2012.06 구독 인증기관·개인회원 무료
        Ski protein is a nuclear transcription factor that does not bind DNA directly. Due to its unique binding properties with multiple factors, Ski could perform various roles in the regulation of both cellular proliferation and differentiation. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to examine whether the initiation of luteinization with luteinizing hormone (LH) directly regulates expression of Ski in the luteinized granulosa and luteal cells after ovulation by in vitro models. RT-PCR and real time PCR analysis respectively revealed that LH had no effect on c-Ski mRNA expression in the cultured granulosa cells regardless of LH treatment. Though Ski protein isabsent in granulosa cells of preovulatory follicle, its mRNA(c-Ski) was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggested that its expression is regulated post-transcriptionally. Moreover, expression of mRNA of Arkadia, an E3 ubiquitin ligases, in luteinizing granulosa cells in vivo was assessed by real time-PCR. The levels of Arkadia mRNA expression were unchanged during follicular growth and post ovulatory luteinization. These findings suggest that Ski protein level may be regulated during luteinization at translational and/or post-translational level but not by Arkadia.
        16.
        2012.06 구독 인증기관·개인회원 무료
        Sloan-Kettering virus gene product of a cellular pro-oncogene c-Ski is an unique nuclear pro-onco protein and belongs to the Ski/Sno proto-oncogene family. Ski plays multiple roles in a variety of cell types, it can induce both oncogenic transformation and terminal muscle differentiation when expressed at high levels. Ski protein is implicated in proliferation/differentiation in a variety of cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells, however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of this study was, by means of immunohistochemical methods, to locate Ski protein in the rat ovaries during ovulation and corpora lutea(CL) formation to predict the possible involvement of Ski in luteinization. In addition, to examine whether the initiation of luteinization with luteinizing hormone(LH) directly regulates expression of Ski in the luteinized granulosa and luteal cells after ovulation by in vivo models. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rat, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone(LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of corpus luteum(CL). These results indicate that Ski is profoundly expressed in the luteinized granulosa cells and luteal cells of CL during luteinization, and suggest that Ski may play a role in luteinization of granulosa cells.
        17.
        2012.06 구독 인증기관·개인회원 무료
        For reconstituting genetic resource(Korean Native Chicken: KNC) with grem-line chimeric chicken made with cryopreserved biastdermal cells, the experiments were carried out to optimize cryopreservating conditions. Stage X biastdemal cells were collected from KNC embryos and dissociated. Cells were susupended in medium containing cyopretectant and fetal bovine serum(FBS), and distributed into plastic ampules. Cell susupensions were seeded to induce ice formation at — 7℃ to — 35℃ at in the experiments, the effect of modification of dissociation way, concentration of FBS and cell density on the vaibility of frezen-thawed cells were investigated by trypan blue exclusion. Then change the way of cell dissociation from pipetting to short time vortexing, viability of frozen- thawed cell tended to be increaced from 29 % to 52 %. Increase concentraition of FBS in frozen medium from 20 % to 80 % made viability of thawed cell from 28 % to 35 %. The viability of thawed cells were 33.9% frozen at 2 embryos/ 0.5 ml, and 43.6 % frozen at 20embryos/0.5 ml. Furthermore, combination of three modifications make big improvement. The viability of frozen-thawed cell was 60 % for combinated method, and 41 % for general method. This result means the advance to practical cryoreservation of blastdermal cell of the KNC(Ogolgye breed).
        18.
        2012.06 구독 인증기관·개인회원 무료
        Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinizationto predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rats, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of the corpus luteum (CL). Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-Ski)was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggests that its expression is regulated post-transcriptionally.
        19.
        2012.06 구독 인증기관·개인회원 무료
        Cryopreservation of avian semen is a useful tool to preserve genetic resource for aim of preventing extinction induced by infectious disease like avian influenza. Unlike those of mammals, data from chicken cryopreserved semen has not been showed feasible results. So, various cryoprotectants and diluents have been examined in many methods. In this report, as a major ingredient of avian seminal plasm, glutamine was substituted by alanyl glutamine to enhance physiological stability of chicken semen during freezing. We studied effect of glycerol and Dimethylacetamide(DMA) on motility and progressive motility of spermatozoa using glutamine diluent(EK-G) or alanyl glutamine diluent(EK-A) condition. The semen of Ogye was collected twice a week by the dorso-abdominimal massage method and diluted with same volume of EK-G or EK-A at 25℃ and stored for 10 min at 4℃ in cold chamber. Glycerol or DMA was added to diluted semen to reached 7% of final concentration at 4℃. After 3min of equilibration, the diluted semen was packed into 0.25ml straws and subjected to cryopreservation used freezing equipment. The packed straw were placed on height 5 cm above surface of liquid nitrogen(LN2) and held for 10min. After preserved for 2 weeks, the straw was thawed onto the 4℃ cooling bath. The images of motility and progressive motility spermatozoa were recorded by digital image recorder and analyzed by manual. The results showed 68.5% motility and 34.1% progressive motility in DMA/EKA diluent, 31.45% and 17.6% in glycerol/EKA, 45.4% and 8.6% in DMA/EKG, and 9.7% and 6.4% in glycerol/EKG. With these results, the alanyl glutamine and DMA could be used as a main composition of diluent and cryoprotectant for cryopreservation of chicken semen.
        20.
        2012.03 구독 인증기관 무료, 개인회원 유료
        For reconstituting genetic resource(Korean Native Chicken: KNC) with grem-line chimeric chicken made with cryopreserved biastdermal cells, the experiments were carried out to optimize cryopreservating conditions. Stage X biastdemal cells were collected from KNC embryos and dissociated. Cells were susupended in medium containing cyopretectant and fetal bovine serum(FBS), and distributed into plastic ampules. Cell susupensions were seeded to induce ice formation at —7 ℃ to —35 ℃ at in the experiments, the effect of modification of dissociation way, concentration of FBS and cell density on the vaibility of frezen-thawed cells were investigated by trypan blue exclusion. Then change the way of cell dissociation from pipetting to short time vortexing, viability of frozen-thawed cell tended to be increaced from 29 % to 52 %. Increase concentraition of FBS in frozen medium from 20 % to 80 % made viability of thawed cell from 28 % to 35 %. The viability of thawed cells were 33.9% frozen at 2 embryos/ 0.5ml, and 43.6 % frozen at 20 embryos/0.5 ml. Furthermore, combination of three modifications make big improvement. The viability of frozen-thawed cell was 60 % for combinated method, and 41 % for general method. This result means the advance to practical cryoreservation of blastdermal cell of the KNC(Ogolgye breed).
        4,000원
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