The larvicidal activities of 11 Myrtaceae essential oils and their components against Aedes aegypti were tested by the immersion method. We also tested the acute toxicity of 4 active oils and their components against the water flea, Daphnia magna. Further, the aqueous residues of these oils and their components were determined at 2 and 7 days after suspending in water. Among the 11 oils tested, 0.1 mg/mL of Melaleucalinariifolia, M. dissitiflora, M. quinquenervia, and Eucalyptus globulus oils showed strong larvicidal activity against A. aegypti. Among the test compounds, allyl isothiocyanate, γ-terpinene, p-cymene, (+)-limonene, (-)-limonene, γ-terpinene, and (E)-nerolidol showed strong larvicidal activity against A. aegypti. The acute toxicity test revealed M. linariifolia was the most toxic to D. magna. Among test compounds, allyl isothiocyanate was the most toxic to D. magna. Two days after treatment, the residues of M. dissitiflora, M. linariifolia, M. quinquenervia, and E. globulus oils in water were 55.4, 46.6, 32.4, and 14.8%, respectively. Low concentrations of allyl isothiocyanate, γ -terpinene, p-cymene, (-)-limonene, (+)-limonene, and γ-terpinene were detected in the water at 2 days after treatment. Therefore, Myrtaceae essential oils and their components could be developed as control agents against mosquito larvae.

The objectives of this study were to compare the biochemical profiles with biogroups for the identification of Cronobacter spp. (formally known as Enterobacter sakazakii) isolates using biochemical identification kits. A total of 38 Cronobacter spp. contained 5 clinical, 31 food, and 2 environmental isolates were used. All isolates were identified as Cronobacter spp. with the Vitek II system and ID 32E kit. The API 20E kit identified all isolates as Cronobacter spp. but the percentage identification was 51.1% for 16 of 38 isolates. These strains were contained to Biogroup 2, 9, 10, and 11. The utilization of inositol is a factor determining the percentage identification of Cronobacter spp. with the API 20E kit.

DNA barcode is known to be successfully applied in identification on the members of Insecta. In recent studies, however, it was known that the DNA approach may fail in several taxa with following cases: (1) very recent speciation and hybridization, (2) recent diverged groups with complex gene histories, (3) the spread of maternally transmitted bacteria, (4) adding more than one geographical race and at least one congener, (5) different levels of dispersal. In this study, we taxonomically review on the Korean Hatchiana using the morphological data and DNA barcodes. In morphology, they are distinct from each other by the characteristics of body coloration, eye, pronotum, scutellum, and aedeagus. In molecular data, however, the interspecific sequence distance ranged from 0.0-3.4%. This result is caused by H. glochidiatus, of which the sequence divergence is 0.2-2.8% in H. rosinae, 0.8-2.6% in H. baekripoensis, and 0.0-3.3% in H. jirisanensis. Also, H. glochidiatus produces mixed-clusters with H. rosinae and H. jirisanensis in NJ phenogram. Through this presentation, therefore, we discuss on why the four Korean Hatchiana species distinct by morphological characters produce mixed-clusters in DNA barcoding.

The techniques of IVM, IVF and IVC of canine oocytes may provide useful information for gamete salvage programs and the conservation of endangered canidae. This investigation has been made to determine the efficiency of in vitro maturation (IVM) as a basic experiment to study the development of canine oocytes after in vitro fertilization (IVF). The rate of oocytes developing to the MII stage was higher in the hormone treated group (10 IU/ml hCG+eCG, 14.7%, p<0.05) than in the control group (0 IU/ml hCG+eCG, 10.0%). The monospermy and pronuclear rates of canine oocytes were investigated after caffeine treatment on IVF. Canine oocytes were fertilized in the Fert‐TALP medium supplemented with 0, 10, 20 or 30 mM caffeine (Fert I, Fert II, Fert III or Fert IV, respectively). The highest pronuclear formation rate was obtained in the Fert I for 24 h IVF (6.7%, 6/89). Therefore, it is believed that unlike in other mammals, caffeine in canine IVF does not increase the efficiency of fertilization rate, and is not an important factor.

Our previous study showed that transgenic (TG) pigs harboring human EPO (hEPO) gene have been shown to have reproductive disorders, including low pregnancy rates, irregular estrus cycle and low little size. To investigate these reasons, we assessed estrus behavior (standing response) and plasma 17B-estradiol (E2) level, which partly reflect reproductive function, during the estrus cycles after synchronization and superovulation by hormone treatments. Then, we analysed blood composition and expression of hEPO gene in TG pigs. Pigs were injected with PG600. After 10 days, pigs were fed with Regumate porcine for 6 days. Blood samples were collected from jugular vein. Analysis of blood composition and E2 level were measured by Hemavet 950 and E2 ELISA kit, respectively. And, the expression of hEPO gene in reproductive organs was quantitated by real-time RT-PCR. The percentage of estrus behavior in TG was significantly decreased. Hematocrit (HCT), hemoglobin (Hb) concentration and red blood cell (RBC) number were significantly higher in TG than wild type (WT). On the other hand, high expression of hEPO gene in TG was observed in the mammary gland as well as in the uterus. Moreover, plasma E2 level was significantly higher in TG than WT. These results suggest that nonspecific expression of hEPO gene in the other organs of TG may affect blood composition and plasma E2 level, thereby causing reproductive disorders.

This study was carried out to investigate the effects of cryoprotectants, warming solution and removal of lipid on open pulled straw vitrification (OPS) method of porcine embryos produced by nuclear transfer (NT) of fetal fibroblasts. All solutions used during vitrification were prepared with holding medium consisting of 25 mM Hepes buffered TCM199 medium containing 20% fetal bovine serum (FBS) at 38.5℃. The blastocysts derived from NT with or without lipid were vitrified in each medium of different concentrations of dimethyl sulfoxide (DMSO) and ethylene glycol (EG). Also, blastocysts after cryopreservation were warmed into different concentrations of sucrose in warming solution. The optimal concentrations of cryoprotectants in vitrification solution were 10% DMSO + 10% EG in vitrification solution 1 (VS1) and 20% DMSO + 20% EG in vitrification solution 2 (VS2). The optimal concentrations of sucrose were 0.3 M sucrose in warming solution 1 (WS1) and 0.15 M sucrose in warming solution 2 (WS2). Lipid removal from oocytes before NT enhanced the viability of NT embryos after vitrification. Our results show that use of the OPS method in conjunction with lipid removal provides effective cryopreservation of porcine nuclear transfer embryos.

Oral squamous carcinoma (OSC) is the most common malignant neoplasm of the oral mucosa. Although the etiology of OSC is not fully understood, accumulated evidences indicate that the activation of proto-oncogenes and the inactivation of tumor suppressor genes underlie the disease development. An OSC cell line, YD-9 was newly established and characterized. However, the mutational analysis of p53 gene was not performed. Thus, in this study, the presence of mutation in the p53 gene was examined by amplification of exon-4 to -8 and subsequent DNA sequencing. Two point mutations were found in exon-4 and -6: A to G, resulting in amino acid change Tyr to Cys in exon-4, and C to G, resulting in amino acid change Gly to Arg in exon-6, respectively. Any mutation was not found in the exon-5, -7 and -8. The presented results would contribute to basic research to understand the biological mechanism of OSC using YD-9 cells.