Narcissus (Narcissus spp.) bulbs were used to investigate contagious viral retention in the dormant stage. The amplified polymerase chain reaction (PCR) bands were screened using universal potyvirus primers and sequenced to identify specific viruses. To identify individual viruses, primers for specific viruses were designed, and reverse transcription (RT)-PCR was performed. The PCR fragments were sequenced and compared by phylogenetic analysis. Three potyviruses, cyrtanthus elatus virus A (CyEVA), narcissus yellow stripe virus (NYSV), and narcissus late season yellows virus (NLSYV) were singly or doubly detected in 18 samples from six cultivars of the 38 samples representing eight cultivars that were tested. Based on RT-PCR using specific primers, CyEVA was detected in the split corona daffodil cv. Orangery. NLSYV and NYSV frequently occurred as co-infections with each other in the double daffodil cv. Tahiti, and the N. cyclamineus daffodil cv. Tete-a-tete and cv. Tete Boucle. Results has shown that at least three potyviruses are present in imported Narcissus bulbs.

This study was performed to investigate the content of carotenoid (α-carotene, β-carotene, β-cryptoxanthin, capxanthin, lutein, lycopene, zeaxanthin) and physicochemical characteristics (size, color, dietary fiber, total tannin content) of unripen and ripen persimmons (Diospyros kaki) by seven cultivars. The length of the unripen and ripen persimmons ranged from 40.87-64.75 and 48.80-80.29 cm, the width were from 44.03 to 66.73 and 57.65 to 91.53 cm, respectively. Ripen persimmons were showed in the highest Hunter’s L, a and b values. Total tannin content were resulted of unripen- and ripen persimmons ranged from 7.58 to 19.80 and 2.36 to 5.85 mg/g. Total carotenoid content were from 1.09 to 6.45 and 7.46 to 29.46 μg/g, respectively. From the above results, unripen- and ripen persimmon fruit could be useful for the health functional food.

Proteinaceous insecticidal proteins, Cry proteins, from Bacillus thuringiensis (Bt) are insecticidal proteins that are highly active against several species of Lepidoptera. Thus, cry genes encoding these Cry proteins have been widely applied for construction of transgenic crops resistant to pest insects. In this study, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Spodoptera exigua and Ostrinia furnacalis were identified. We used site-directed mutagenesis to improve the insecticidal activity of Mod-Cry1Ac, resulted 31 mutant cry genes. These mutant cry genes encodes potent insecticidal proteins in the form of crystalline protoxins of 95 kDa. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activities of these mutant Cry proteins against to larvae of P. xylostella, S. exigua and O. furnacalis were assayed, they showed higher or similar insecticidal activity compared to those of Cry1Ac and Cry1C. Especially, Mutant-N16 is considered to have the potential for the efficacious biological insecticide since it showed the highest insecticidal activity.

Crystals of proteinaceous insecticidal proteins, Cry proteins, produced by Bacillus thuringiensis (Bt) have been generally used to control insect pests. In this study, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Spodoptera exigua and Ostrinia furnacalis were identified. To construct novel cry genes with enhanced insecticidal activity, we randomly mutated these 23 amino acid sequences by in vitro muti site-directed mutagenesis, resulting in totally 24 mutant cry genes. For further characterization, these mutant cry genes were expressed as a fusion protein with polyhedrin using baculovirus expression system. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activities of these mutant Cry proteins against to larvae of P. xylostella and S. exigua were assayed, they showed higher or similar insecticidal activity compared to those of Cry1Ac and Cry1C. Especially, among them Mutant-N16 showed the highest insecticidal activity against to both of P. xylostella and S. exigua. Therefore, Mutant-N16 is considered to have the potential for the efficacious biological insecticide.

Varieties of Bacillus thuringiensis (Bt) crystal proteins, Cry proteins, have so far been found as one of the most successful biological control agents which are safe to natural environments for a long time. Recently, cry genes encoding these Cry proteins have been widely applied for construction of transgenic crops resistant to pest insects. In this study, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Spodoptera exigua and Ostrinia furnacalis were identified. To construct novel cry genes with improved insecticidal activity, we randomly mutated these 23 amino acid sequences by in vitro muti site-directed mutagenesis, resulting in totally 24 mutant cry genes. For further characterization, these mutant cry genes were expressed as a fusion protein with polyhedrin using baculovirus expression system. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. In the further study, we plan to investigate their insecticidal activity against Plutella xylostella, S. exigua and O. furnacalis larvae.

We conducted a study to investigate milk and dairy products consumption among elementary school students to identify ways to increase their intake of milk and dairy products. We asked 518 students in Seoul to fill out questionnaire. Only 55.6% of the subjects consumed milk daily, and 43.7% of them drank at least 1 cup per day. The frequency and quantity of milk consumption were higher in male students than female students. The majority of the subjects consumed whole milk, and most students(59.5%) preferred flavored milk to whole milk. The reasons given for drinking milk included ``wanting to be tall``(66.1%) and ``for good health``(47.1%), while the main reason given for not drinking milk was stomach pain (68.4%). Records of having an unpleasant experience and upset stomach after drinking milk occurred at a higher rate for those who did not drink milk(84.2%) than for those who did(53.3%). Of the students questioned, 36.9% consumed dairy products other than milk 3～4 times per week, and liquid-type yoghurt(43.8%) and ice cream(35.4%) were the preferred dairy products among students. The reasons given for consuming dairy products were ``good taste``(56.6%), ``good to eat``(46.6%), ``wanting to be tall``(32.4%), and ``for good health``(25.4%). Among those students who did not consumed dairy products, the major reason given was ``family does not eat at home``(33.3%). After consuming the dairy products, 71.4% of participants thought that dairy products did not result in physical improvement. Most students had experienced purchasing milk and dairy products by themselves. When they bought milk or dairy products, the reasons given for making a particular selection were ``shelf-life``(61.6%) for milk, and ``favorite dairy products``(54.1%) for dairy products. According to participants, the factors that need to be considered for milk and dairy product consumption among elementary school students are ``higher nutrition`` (60.8%), ``better sanitation``(57.3%), and ``better quality and taste``(55.2%).

The Egr family of zinc finger transcription factors is rapidly induced by various mitogens and regulates cell growth, differentiation, and apoptosis. While it is clear that loss of Egr1 leads to anovulatory infertility due to LHβ deficiency in female mice, molecular function of Egr1 in male reproduction has not been clearly investigated. Here, we demonstrate that Egr1 acts as an intrinsic transcription factor in Leydig cells to regulate their proliferation and steroidogenesis in the testis as well as an extrinsic factor for male reproduction via LHβ transcription in the pituitary. Egr1 is predominantly expressed in spermatogonia and Leydig cells in immature testes and later detected in some of these cell types in mature testes. The fertility potential of Egr1(-/-) male mice is relatively deteriorated even at 2 month-old age and aggravated with aging. The incidence of abnormalities of seminiferous tubules such as Sertoli cell only was dramatically increased with aging. The number and mean size of Leydig cells were significantly reduced in Egr1(-/-) testes. The impairment of Leydig cells is consistent with significant reduction in levels of testosterone and expression of factors critical for steroidogenesis such as StAR in Egr1(-/-) testes. Exogenous administration of hCG rapidly and transiently induced Egr1 expression in Leydig cells culture in vitro. hCG could reinstate reduced mean size of Leydig cells but not reduced number of Leydig cells and aberrantly low StAR expression, suggesting that Egr1 has critical functions for Leydig cell proliferation and their steroidgenesis. In addition, daily sperm production and in vitro fertilization (IVF) competence were significantly reduced, and apoptosis was facilitated in these mice. Furthermore, hCG administration to compensate for relatively low LH levels in Egr1(-/-) males could not restore the compromised reproductive phenotypes such as IVF competence and apoptosis in these mice. Interestingly, expression of Egr2, a member of Egr family, is significantly elevated in Egr1(-/-) Leydig cells suggesting that genetic compensation of Egr2 may alleviate phenotypic aberration of Egr1(-/-) male testes. Collectively, these results suggest that Egr1 act as an intrinsic transcription factor required for proliferation and steroidogenesis of Leydig cells to govern spermatogenesis in the testis.