We have determined the complete mitochondrial genome of the yellow-spotted long horned beetle, Psacothea hilaris (Coleoptera: Cerambycidae), an endangered insect species in Korea. The 15,856-bp long P. hilaris mitogenome harbors gene content typical of the animal mitogenome and a gene arrangement identical to the most common type found in insect mitogenomes. As with all other sequenced coleopteran species, the 5-bp long TAGTA motif was also detected in the intergenic space sequence located between tRNASer (UCN) and ND1 of P. hilaris. The 1,190-bp long non-coding A+T-rich region harbors an unusual series of seven identical repeat sequences of 57-bp in length and several stretches of sequences with the potential to form stem-and-loop structures. Furthermore, it contains one tRNAArg-like sequence and one tRNALys-likes equence. Phylogenetic analysis among available coleopteran mitogenomes using the concatenated amino acid sequences of PCGs appear to support the sister group relationship of the suborder Polyphaga to all remaining suborders, including Adephaga, Myxophaga, and Archostemata. Among the two available infraorders in Polyphaga, a monophyletic Cucujiformia was confirmed, with the placement of Cleroidea as the basal lineage for Cucujiformia. On the other hand, the infraorder Elateriformia was not identified as monophyletic, thereby indicating that Scirtoidea and Buprestoidea are the basal lineages for Cucujiformia and the remaining Elateriformia.

Mutations in DLX3 are associated with both autosomal dominant hypoplastic hypomaturation amelogenesis imperfecta (ADHHAI) and tricho-dento-osseous (TDO) syndrome. ADHHAI is caused by a c.561_562delCT (2bp-del DLX3) mutation whereas TDO syndrome is associated with a c.571_574delGGGG (4bp-del DLX3) mutation. However, although the causal relationships between DLX3 and an enamel phenotype have been established, the pathophysiological role of DLX3 mutations in enamel development has not yet been clarified. In our current study, we prepared expression vectors for wild type and deletion mutant DLX3 products (4bp-del DLX3, 2bp-del DLX3) and examined the effects of their overexpression on the expression of the enamel matrix proteins and proteases. Wild type DLX3 enhanced the expression of matrix metalloprotease 20 (MMP20) mRNA and protein in murine ameloblast-like cells. However, neither a 4bp-del nor 2bp-del DLX3 increased MMP20 expression. Wild type DLX3, but not the above DLX3 mutants, also increased the activity of reporters containing 1.5 kb or 0.5 kb of the MMP20 promoter. An examination of protein stability showed that the half-life of wild type DLX3 protein was less than 12 h whilst that of both deletion mutants was longer than 24 h. Endogenous Dlx3 was also found to be continuously expressed during ameloblast differentiation. Since inactivating mutations in the gene encoding MMP20 are associated with amelogenesis imperfecta, the inability of 4bp-del or 2bp-del DLX3 to induce MMP20 expression suggests a possible involvement of such mutations in the enamel phenotype associated with TDO syndrome or ADHHAI.

To determine the characteristics of the Korean porcine reproductive and respiratory syndrome virus (PRRSV), CA, which was isolated from the serum of an infected pig in 2006, we investigated the nucleotide sequence and expression of the structural ORFs (ORFs 2 to 7) using the bApGOZA system. We found that the structural ORFs 2 to 7 of CA consisted of 3188 nucleotides that were the same as those formed from VR-2332. Comparison of the CA with the other strains revealed nucleotide sequence identity ranging from 89.8 to 99.5%. To better understand the genetic relationships between other strains, phylogenetic analyses were performed. The CA strain was closely related to the other North American genotype strains but formed a distinct branch with high bootstrap support. Additionally, expression levels of the PRRSV proteins in Sf21 cells were strong or partially weak. The results of this study have implications for both the taxonomy of PRRSV and vaccine development.

In order to establish a year round indoor-rearing system for Copper butterflies; large copper butterfly, Lycaena dispar, the effect of temperature on larval development and diapause was investigated. Temperature has been suggested as an important factor regulating the developmental rate, length of life, and survival rate from insect. As temperature increased, the developmental period was gradually shorten. The developmental periods of large copper larvae had a range of 11.0 days to 28.5 days at 30℃ and 17.5℃ respectively. The highest emergence rate was 94.2% recorded at 20℃. And the low emergence rate was 72.7% under 17.5℃. We investgated the sensitive stages to diapause induction in the larger copper effect of temperature and photoperiod. The experiment involves transfer of individuals from diapause averting (LD 16:8h, 25℃) to diapause inducing condition (LD 8:16h, 20℃) at various stages. Diapause was induced in 95.2% insect transferred at hatching larvae, in 15.6% of insects transferred at 2nd stadium molt, in 0% of insects transferred at after 3rd stadium molt. Percentage diapause induction increase with the length of short days and low temperature experienced. The main stage sensitive to photoperiod and temperature induction of diapause determination is the early first larval instar. The diapause induction began 14 days and ended 20 days after hatching larvae (LD 8:16h, 20℃).

In this study, we determined the complete mitochondrial genome of the jewel beetle, Chrysochroa fulgidissima (Coleoptera: Buprestidae), from four overlapping fragments. The 15,592-bp long C. fulgidissima mitogenome exhibits a gene arrangement and content identical to the most common type in insects. The start codon of the C. fulgidissima COI gene is unusual, in that no typical ATN codon is available. The 875-bp A+T-rich region is the shortest among the coleopteran mitogenomes that have thus far been sequenced in their entirety. The most unusual feature of the genome is the presence of three tRNA-like sequences within the A+T-rich region: two tRNALeu(UUR)-like sequences and one tRNAAsnlike sequence. These sequence stretches evidence the proper anticodon sequence and the potential to form secondary structures, but also harbor many mismatches in the stems. Phylogenetic analysis using a concatenation of 13 amino acid sequences of protein-coding genes among the available sequenced species of coleopteran superfamilies (Buprestoidea and Elateroidea belonging to the infraorder Elateriformnia, and Chrysomeloidea and Tenebrioroidea belonging to the infraorder Cucujoiformia) by Bayesian inference, maximum-parsimony analyses, and maximum-likelihood analysis unexpectedly revealed a lack of support for monophyletic Elateriformia.

Sclerodermus harmandi populations were collected from 6 Korean regions (Seoul, Gangwon, Chungcheong, Jeolla, Gyeonasang and Jeju provinces), 1 Chinese region (Nanjing) and 1 Japanese region (Tokyo). Above all was identified as the same species based on morphological characteristics. In present study, we compared the intra-specific characteristics of regional isolated populations of S. harmandi based on nucleotide and amino acid sequences of variant genomic and mitochondrial loci: the full length of internal transcribed spacer 1 and 2 (ITS1 & ITS2), the complete cytochrome oxidase subunit I and II (COI & COII) and tRNA genes for aspartate and lysine and 5'end of ATPase 8 genes. There were no significant differences among the analysed 9 populations regardless of regional segregation. The nucleotide and translated amino acid sequences similarities were significantly high, despite some sequence differences were found in same loci. This result support the report based on the morphological characteristics. However, we are conducting further study to identify whether sequence differences in specific loci are the characteristics of individual level in population or population level and to analyse the full sequences of mitochondrial DNA by regional segregation.

Cementum is the mineralized tissue of the tooth. It is similar to bone in several aspects but it differs from bone. Human bone marrow stromal cells (BMSC) and human cementum derived cells (HCDC) (10,000 cells/cm²) were plated in 6 well plates as feeder cells. The next day, mouse bone marrow cells (1.5 million cells/cm²) were added. One group of these plates were incubated in serum-free conditioned medium (SFCM) generated from BMSC or HCDC supplemented with 2% FBS, parathyroid hormone (PTH), 1, 25 dihydroxyvitamin D₃ (Vit. D₃) and dexamethasone, or plain medium with the same supplements. Another group of plates were cocultured with BMSC or HCDC in plain medium supplemented with 2% FBS, PTH, Vit. D₃and dexamethasone. Plates grown without SFCM or coculture were used as controls. After 10 days, the cells were stained for tartrate-resistant acid phosphatase (TRAP). BMSC were found to support osteoclast formation under normal conditions. This was inhibited however by both SFCM generated from HCDC and also by coculture with HCDC. In addition, HCDC themselves did not support osteoclast formation under any conditions. Our results thus indicate that HCDC do not support osteoclast formation in vitro and that soluble factor (s) from HCDC may inhibit this process. In addition, we show that this inhibition also involves an active mechanism that is independent of osteoprotegerin, a feature that may distinguish cementoblasts from other cells present in periodontium.

Recent studies on nuclear transfer and induced pluripotent stem cells have demonstrated that differentiated somatic cells can be returned to the undifferentiated state by reversing their developmental process. These epigenetically reprogrammed somatic cells may again be differentiated into various cell types, and used for cell replacement therapies through autologous transplantation to treat many degenerative diseases. To date, however, reprogramming of somatic cells into undifferentiated cells has been extremely inefficient. Hence, reliable markers to identify the event of reprogramming would assist effective selection of reprogrammed cells. In this study, a transgene construct encoding enhanced green fluorescent protein (EGFP) under the regulation of human Oct4 promoter was developed as a reporter for the reprogramming of somatic cells. Microinjection of the transgene construct into pronuclei of fertilized mouse eggs resulted in the emission of green fluorescence, suggesting that the undifferentiated cytoplasmic environment provided by fertilized eggs induces the expression of EGFP. Next, the transgene construct was introduced into human embryonic fibroblasts, and the nuclei from these cells were transferred into enucleated porcine oocytes. Along with their in vitro development, nuclear transfer embryos emitted green fluorescence, suggesting the reprogramming of donor nuclei in nuclear transfer embryos. The results of the present study demonstrate that expression of the transgene under the regulation of human Oct4 promoter coincides with epigenetic reprogramming, and may be used as a convenient marker that non-invasively reflects reprogramming of somatic cells.

The endogenous retrovirus-like elements (HERVs) found on several human chromosomes are somehow involved in gene regulation, especially during the transcription level. HERV-H, located on chromosome Xp22, may regulate gastrin-releasing peptide receptor (GRPR) in connection with diverse diseases. By suppression subtractive hybridization screen on SV40-immortalized lung fibroblast (WI-38 VA-13), we discovered that expression of HERV-HX2, a clustered HERV-H sequence on chromosome X, was upregulated in immortalized lung cells, compared to that of normal cells. Expression of HERV-HX2 was then analyzed in various cell lines, including normal somatic cells, cancer cells, SV40-immortalized cells, and undifferentiated and differentiated human embryonic stem cells. Expression of HERV-HX2 was specifically upregulated in continuously-dividing cells, such as cancer cells and SV40-immortalized cells. Especially, HERV-HX2 in HeLa cells was highly upregulated during the S phase of the cell cycle. Similar results were obtained in hES cells, in which undifferentiated cells expressed more HERV-HX2 mRNA than differentiated hES cells, including neural precursor and endothelial progenitor cells. Taken together, our results suggest that HERV-HX2 is upregulated in cancer cells and undifferentiated hES cells, whereas downregulated as differentiation progress. Therefore, we assume that HERV-HX2 may playa role on proliferation of cancer cells as well as differentiation of hES cells in the transcriptional level.

We have investigated the optical properties of the global haze on Titan from spectra recorded between 7100 and 9200Åwhere CH4 absorption bands of various intensities occur. The Titan spectra were obtained on Feb. 23, 2005 (UT), near the times of the Cassini T3 flyby and Huygens probe, using an optical echelle spectrograph (BOES) on the 1.8-m telescope at Bohyunsan Observatory in Korea. In order to derive the optical properties of the haze as a function of altitude, we developed an inversion radiative-transfer program using an atmospheric model of Titan and laboratory CH4 absorption coefficients available from the literature. The derived extinction coefficients of the haze increase toward the surface, and the coefficients at shorter wavelengths are greater than those at longer wavelengths for the 30 - 120 km altitude range, indicating that the Titanian haze becomes optically thin toward the longer wavelength range. Total optical depths of the haze are estimated to be 1.4 and 1.2 for the 7270 -7360Åand 8940 -9150Å ranges, respectively. Based on the Huygens/DISR data set, Tomasko et al. (2005) reported total optical depths of 2.5 - 3.5 at 8290Å depending on the assumed fractal aggregate particle model. The total optical depths based on our results are smaller than those of Tomasko et al., but they partially overlap with their results if we consider a large uncertainty from possible variations of the CH4 mixing ratio over Titan's disk. We also derived the single scattering albedo of the haze particles as a function of altitude: it is less than 0.5 at altitudes higher than ~150Km the average particle radius is smaller than the wavelengths, whereas near the surface, it becomes comparable or greater.