• Korean Journal of Environmental Biology
• /
• v.38 no.4
• /
• pp.650-657
• /
• 2020

We conducted a phylogeographic analysis of Korean endemic Zacco koreanus populations inhabiting the East-flowing river (Gangneung Yeongokcheon; GY, Yangyang Namdaecheon; YN), the Han River (Seomgang; SG, Soksacheon; SS), and the Nakdong River(Gilancheon; GA) using the mitochondrial DNA cytochrome oxidase I (COI) gene (619 bp). Population genetic analysis was further performed to assess the population connectivity for the GY river where there is a large number of human-made artificial weirs with several fishways. The phylogeographic analysis revealed that while the populations of the East-flowing river and those of the Han River formed a monophyletic lineage, the Nakdong River individuals represented a distinct lineage with 3.7-4.2% (mean=4.0%) genetic distance from the other lineages. The population genetic analysis of the GY showed that a mid-stream population harbored relatively higher mitochondrial diversity relative to up- and down-stream populations, and there was no genetic differentiation between these three populations. The latter findings might suggest high genetic connectivity between the populations via genetic flow along the fishways. However, an analysis using faster-evolving genetic markers, such as microsatellites, is needed to confirm the findings of high population connectivity. Our study suggests the possibility of the presence of cryptic species in Z. koreanus in the Nakdong River basin. However, further study with more individual samples as well as additional markers or even more advanced genomic tools is required to test our hypothesis. Ecological or phenotypic analyses should be conducted to test whether the observed Nakdong River lineage represents a different or cryptic species, or simply hidden, but excessive, intraspecific diversity.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.4
• /
• pp.535-538
• /
• 2000

Streptomyces lavendulae FRI-5 produces the ${\gamma}$-butyrolactone autoregulator IM-2, which is required for nucleoside antibiotic producetion. We have developed a system for introducing DNA into S. lavendule FRI-5 via conjugal transfer from Esherichia cole. Conditions were established for conjugation of the oriT-and attP-containing plasmid pSET152 from E. coli ET12567 (pUZ8002) to FRI-5. Conjugation resulted in integration of the plasmid at the chromosomal C31 attB site. The frequency of intergeneric conjugation varied with the medium used. The highest frequency ($1.6\times10-5$ per recipient) was obtained on ISP medium 2 containing 10mM MgCl2. Southern blot and phenotypic analyses of exconjugants revealed that S. lavendulae FRI-5 contains a unique C31 attB site, and that integration of heterologous DNA into the attB site did not interfere with morphological differentiation or IM-2-dependent signal transduction, including the production of a blue pigment. This system will now enable detailed genetic analysis of the regulation of antibiotic production in S. lavendulae FRI-5.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.10
• /
• pp.1301-1307
• /
• 2014

White-rot fungi of the genus Bjerkandera are cosmopolitan and have shown potential for industrial application and bioremediation. When distinguishing morphological characters are no longer present (e.g., cultures or dried specimen fragments), characterizing true sequences of Bjerkandera is crucial for accurate identification and application of the species. To build a framework for molecular identification of Bjerkandera, we carefully identified specimens of B. adusta and B. fumosa from Korea based on morphological characters, followed by sequencing the internal transcribed spacer region and 28S nuclear ribosomal large subunit. The phylogenetic analysis of Korean Bjerkandera specimens showed clear genetic differentiation between the two species. Using this phylogeny as a framework, we examined the identification accuracy of sequences available in GenBank. Analyses revealed that many Bjerkandera sequences in the database are either misidentified or unidentified. This study provides robust reference sequences for sequence-based identification of Bjerkandera, and further demonstrates the presence and dangers of incorrect sequences in GenBank.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.1
• /
• pp.165-171
• /
• 2013

The aim of the present study was to analyze the expression of FHIT and WWOX in nasopharyngeal carcinoma (NPC) and correlations with clinical pathologic features. mRNA expression of the FHIT and WWOX was assessed by real-time fluorescent relatively quantitative PCR in 61 NPC tissues and 45 non-cancerous nasopharyngeal tissues. As a result, mRNA expression levels of both FHIT and WWOX were significantly lower in NPC patients than in control samples (P=0.049 and 0.045, respectively). Moreover, the mRNA expression of both had an inverse relation with larger invasive range (P=0.035 and 0.048, respectively), poor histologic differentiation (P=0.012 and 0.016) and advanced clinical stage (P=0.026 and 0.038). Consistency was found between expression of FHIT and WWOX in the same NPC tissues (r=0.681, P=0.00). In conclusion, synergy between FHIT and WWOX may exist in the development of NPC so that the two factors may be considered as important genetic markers. Detecting the expression of FHIT and WWOX should provide clinically significant information relevatn to tumor diagnosis, progression and treatment modalities for NPC.

• Clinical and Experimental Reproductive Medicine
• /
• v.42 no.2
• /
• pp.33-44
• /
• 2015

The generation of artificial gametes is a real challenge for the scientific community today. In vitro development of human eggs and sperm will pave the way for the understanding of the complex process of human gametogenesis and will provide with human gametes for the study of infertility and the onset of some inherited disorders. However, the great promise of artificial gametes resides in their future application on reproductive treatments for all these people wishing to have genetically related children and for which gamete donation is now their unique option of parenthood. This is the case of infertile patients devoid of suitable gametes, same sex couples, singles and those fertile couples in a high risk of transmitting serious diseases to their progeny. In the search of the best method to obtain artificial gametes, many researchers have successfully obtained human germ cell-like cells from stem cells at different stages of differentiation. In the near future, this field will evolve to new methods providing not only viable but also functional and safe artificial germ cells. These artificial sperm and eggs should be able to recapitulate all the genetic and epigenetic processes needed for the correct gametogenesis, fertilization and embryogenesis leading to the birth of a healthy and fertile newborn.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.49 no.2
• /
• pp.198-207
• /
• 2016

Tanaka’s snailfish, Liparis tanakae (Gilbert and Burke, 1912), is distributed throughout the coasts of Korea. To clarify the population structure of L. tanakae, we analyzed the morphological and genetic variation among individuals sampled from three localities surrounding the Korean peninsula: Boryeong in the Yellow Sea, Jinhae in the Korea Strait and Pohang in the East Sea. Principal component analysis based on 20 morphometric characteristics revealed two slightly distinct groups (Boryeong vs. Jinhae and Pohang). However, canonical discriminant analysis clearly revealed three groups, separated according to locality. Pairwise differentiation index (F_ST) comparisons based on 762-base pairs mitochondrial cytochrome b gene sequences showed that Boryeong significantly differed from Jinhae and Pohang, but Jinhae and Pohang did not significantly differ from each other. Our findings suggest that Korean L. tanakae comprise at least two groups. Further studies using more sensitive DNA markers, such as microsatellite DNA, are required.

• BMB Reports
• /
• v.51 no.5
• /
• pp.207-208
• /
• 2018

Chitinase-Like Proteins (CLPs) are an evolutionarily conserved protein which lose their enzymatic activity for degrading chitin macromolecules. Chitinase-3-like-1 (Chi3l1) is a type of CLP that is highly expressed in epithelial cells, macrophages, etc., and is known to have correlations with type 2 inflammation and cancer. Although the increased level of Chi3l1 in the blood was reported in various disease patients, the function of Chi3l1 in adaptive immunity has been totally unknown. Recently, we found that Chi3l1 is expressed in T cells and has a negative regulatory role in T-cell activation and proliferation. A genetic ablation study of Chi3l1 in T cells showed hyperresponsiveness to TcR stimulation, which increased proliferation and Th1 differentiation. A significant increase of $IFN{\gamma}$ signaling in Chi3l1-deficient T cells synergistically increased Th1 and CTL functions against melanoma cells in vitro and in vivo. In addition, targeted knockdown by Chi3l1 siRNA complexed with the cell-penetrating peptide dNP2, which showed decreased pulmonary melanoma metastasis with increased infiltration of Th1 and CTL in the lung. This study first suggests that Chi3l1 is a novel regulator of Th1/CTL responses and could be a target for treating cancer to increase tumor immunity.

• Journal of Plant Biotechnology
• /
• v.34 no.2
• /
• pp.129-137
• /
• 2007

Intercellular signaling is a crucial biological process for the coordination of cell differentiation, organ development and whole plant physiology. The intercellular movement of macromolecule signals such as proteins and RNAs has emerged as a novel mechanism of cell-to-cell communication in plant. Plasmodesmata, which are intercellular symplasmic channels, provide a key pathway for cell-to-cell trafficking of regulatory proteins / RNAs. This review specifically focuses on integrating the recent understanding on non-cell autonomous macromolecules, their function and regulatory mechanisms of intercellular trafficking through plasmodesmata.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.1
• /
• pp.173-181
• /
• 1992

Duck is an important domestic animal, especially in Asia. Eighty five percent of ducks in the world are kept in Asia, especially in the East and South Asia regions. The ancestor of domesticated ducks was mallard (Anas platylhynchos), which are still migrating between north and southern parts in Eurasia. Ducks have been domesticated in China for at least 3000 years ago. Phylogenetic studies on ducks, employing electrophoresis of blood proteins, indicate a marked difference of genetic constitution between duck breeds in southeast Asia and those in northeast Asia. Duck embryonic ovary is much more active in secretion of sex steroid hormones especially estradiol than the embryonic testes. Estradiol secreted by the embryonic left ovary has an important role in female sexual differentiation in ducks. In the female ducks, plasma LH, estradiol and testosterone levels increase and reach peaks shortly before the first egg, while progesterone level reach a peak shortly after the first egg. In laying ducks oviposition mostly occurs in the last 3 hr of darkness and first hr of light ranging 02:00-06:00 under 14 hr light (05:00-19:00) and 10 hr darkness photoperiodic condition. Measurements of plasma hormone levels reveal that onset of darkness is a major signal for LH release from the pituitary and the subsequent release of progesterone from ovary, and for induction of ovulation in the female duck.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.2
• /
• pp.1155-1157
• /
• 2013

Cancer is a highly complex medical problem with ramifications for public health throughout the world. Most studies have mainly focused on change in the nuclei as being aetiologically responsible. Few have examined the relationship between the cytoplasm and cancer, despite the fact that research has indicated that the cytoplasmic environment is an important factor for cellular differentiation and that the genetic information provided by the nucleus is entirely dependent on this environment for its expression. Gene mutations may be the result, rather than the cause of carcinogenesis. We submit a new concept - "short base sequences" (50-500 bps, including DNA or RNA sequences) in the cytoplasm which could play an important role in carcinogenesis. This is a new theory to explain the origin of the cancer.