• Journal of Animal Reproduction and Biotechnology
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• v.36 no.1
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• pp.2-8
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• 2021

Dimethachlor is a synthetic herbicide, belonging to the chloroacetanilide group, that inhibits the undesirable growth of weeds via the suppression of very long-chain fatty acid synthesis. Although dimethachlor has been shown to run off from agricultural fields into aquatic ecosystems, the toxicity of dimethachlor on aquatic invertebrates and vertebrates is unknown. In our study, we assessed the toxicity of dimethachlor on developing zebrafish embryos by analyzing viability, hatching ability, and phenotypic changes. Embryonic viability decreased from 48 h post-fertilization (hpf) at the highest concentration of dimethachlor. Decreased hatching ratio, shortened body length, and pathological changes in the eye, heart, and yolk sac were observed at sub-lethal concentrations. Additionally, dimethachlor increased the number of apoptotic cells and level of reactive oxygen species 120 hpf. Our results indicate that dimethachlor may act as an anti-developmental toxicant when accumulated in an aquatic environment.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.4
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• pp.323-328
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• 2020

Direct injection of genome editing tools such as CRISPR/Cas9 system into developing embryos has been widely used to generate genetically engineered pigs. The approach allows us to produce pigs carrying targeted modifications at high efficiency without having to apply somatic cell nuclear transfer. However, the targeted modifications during embryogenesis often result in mosaicism, which causes issues in phenotyping founder animals and establishing a group of pigs carrying intended modifications. This study was aimed to establish a genomic PCR and sequencing system of a single blastomere in the four-cell embryos to detect potential mosaicism. We performed genomic PCR in four individual blastomeres from four-cell embryos. We successfully amplified target genomic region from single blastomeres of 4-cell stage embryo by PCR. Sanger sequencing of the PCR amplicons obtained from the blastomeres suggested that PCR-based genotyping of single blastomere was a feasible method to determine mutation type generated by genome editing technology such as CRISPR/Cas9 in early stage embryos. In conclusion, we successfully genotyped single blastomeres in a single 4-cell stage embryo to detect potential mosaicism in porcine embryos. Our approach offers a simple platform that can be used to screen the prevalence of mosaicism from designed CRISPR/Cas9 systems.

• Journal of Korean Neurosurgical Society
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• v.65 no.1
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• pp.138-144
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• 2022

To report two cases of type 1.5 split cord malformation (SCM), a subtype of SCM with combined characteristics of types I and II and to review the relevant literature and propose a new possible pathogenetic theory for type 1.5 SCM. A 52-year-old woman had hemicords within a single dural sac with a dorsal bony septum at the L5 level. A 9-year-old boy had hemicords within a single dural sac with a ventral bony septum and fibrous extension at the L3 level. Both patients underwent microsurgical treatments for removing the bony septum, detethering the spinal cord, and sectioning the filum terminale. The surgical procedure revealed an extradural partial bony septum and hemicords within an intact single dural sac in each patient. Both patients were discharged from the hospital without de novo nerve dysfunction. Published cases have validated that types I and II SCM can overlap. We recommend recent type 1.5 SCM as a normative terminology for this overlapping SCM and report two rare cases of this SCM. We propose an associated pathogenesis consisting of uneven distribution and regression to explain type 1.5 SCM. Furthermore, we postulate that the amount of condensing meninx primitiva might determine whether the left bony septum has fibrous extensions to the opposite dura in type 1.5 SCM.

• BMB Reports
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• v.55 no.5
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• pp.232-237
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• 2022

The Wnt/β-catenin signaling plays crucial roles in early development, tissue homeostasis, stem cells, and cancers. Here, we show that RNF152, an E3 ligase localized to lysosomes, acts as a negative regulator of the Wnt/β-catenin pathway during Xenopus early embryogenesis. Overexpression of wild-type (WT) RNF152 inhibited XWnt8-induced stabilization of β-catenin, ectopic expression of target genes, and activity of a Wnt-responsive promoter. Likewise, an E3 ligase-defective RNF152 had repressive effects on the Wnt-dependent gene responses but not its truncation mutant lacking the transmembrane domain. Conversely, knockdown of RNF152 further enhanced the transcriptional responses induced by XWnt8. RNF152 morphants exhibited defects in craniofacial structures and pigmentation. In line with this, the gain-of-RNF152 function interfered with the expression of neural crest (NC) markers, whereas its depletion up-regulated NC formation in the early embryo. Mechanistically, RNF152 inhibits the polymerization of Dishevelled, which is key to Wnt signaling, in an E3 ligase-independent manner. Together, these results suggest that RNF152 controls negatively Wnt/β-catenin signaling to fine-tune its activity for NC formation in Xenopus embryo.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.455-460
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• 2022

Oxybenzone (Benzophenone-3; BP-3) is a compound used in sunscreens and enters the oceans due to improper disposal. It is known to disrupt the endocrine signaling in marine organisms, leading to immune and reproductive abnormalities in corals, shellfish and fishes. In this study, we investigated the effects of different concentrations of BP-3 (0, 10, 100 and 1,000 ㎍/L) on the fertilized eggs and hatched larvae of Oplegnathus fasciatus. The morphological changes and hatching and survival rates during embryo development were assessed. In addition, the levels of triiodothyronine (T3) were also measured. The hatched larvae exposed to BP-3 at concentrations of 10 and 100 ㎍/L for 24 h displayed malformation of the tail. After 36 h of exposure to BP-3, spinal deformity was observed at all tested concentrations. The hatching rate was significantly low when exposed to 100 ㎍/L of BP-3. A high levels of T3 was observed when the larvae were exposed to BP-3 at a concentration of 1,000 ㎍/L for 96 h (the end of the experiment). This may be related to increased size of larvae at 1,000 ㎍/L BP-3. In conclusion, our results suggested that BP-3 may interfere with embryo development, resulting in a reduction in hatching rate and malformation of larvae.

• International Journal of Oral Biology
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• v.48 no.4
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• pp.33-44
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• 2023

In this review, the regulatory mechanisms of autophagy were described, and its interaction with apoptosis was identified. The role of autophagy in embryogenesis, tooth development, and cell differentiation were also investigated. Autophagy is regulated by various autophagy-related genes and those related to stress response. Highly active autophagy occurrences have been reported during cell differentiation before implantation after fertilization. Autophagy is involved in energy generation and supplies nutrients during early birth, essential to compensate for their deficient supply from the placenta. The contribution of autophagy during tooth development, such as the shape of the crown and root formation, ivory, and homeostasis in cells, was also observed. Genes control autophagy, and studying the role of autophagy in cell differentiation and development was useful for understanding human aging, illness, and health. In the future, the role of specific mechanisms in the development and differentiation of autophagy may increase the understanding of the pathological mechanisms of disease and development processes and is expected to reduce the treatment of various diseases by modulating the autophagic phenomenon.

• Journal of Plant Biotechnology
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• v.4 no.3
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• pp.91-94
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• 2002

An efficient molecular breeding technique for coffee plants was developed. In order to produce transgenic coffee plants, we established a model transformation procedure via Agrobacterium method. We isolated a gene encoding a protein possessing 7-methylxanthine methyltransferase (theobromine synthase) activity, and it was designated as Coffea arabica 7-methylxanthine methyl transferase; CaMXMT. Using this clone, we produced transgenic coffee plants, in which the expression of CaMXMT is suppressed by double-stranded RNA interference (RNAi) andlor anti-sense methods. The expression pattern of CaMXMT was analyzed by reverse transcription-PCR method and we found that, in the transformed cell lines, the level of transcripts were obviously suppressed by RNAi. The endogenous level of caffeine in the transformed cells was dramatically reduced in comparison with non-transformed cells.

• Journal of Life Science
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• v.19 no.5
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• pp.587-592
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• 2009

A dramatic morphological change of embryos occurs at peri-implantation. Maternal and embryonic cross-talk during this period, initiated by signals from embryo(s), provides signals for maternal recognition of pregnancy and establishing and maintaining the pregnancy. However, the cellular, biochemical and genetic processes that direct embryo remodeling in mammalian species are not well studied or understood. In order to identify potential genes responsible for morphological change and cross-talk between embryo and uterus, an initial EST analysis was performed. A catalog of expressed genes (Transcriptome) from the d12 peri-implanting porcine embryos was constructed. Six clones were chosen from the initial ESTs for elucidation of their expression patterns during embryogenesis in early pregnancy. A number of these genes demonstrated unique expression profiles in a tissue, cell-type, and temporal fashion, indicating dynamic regulation of embryonic and endometrial gene expressions at different stages of pregnancy. Cross-talk between the embryo and endometrium of the pregnant uterus has provided a suitable micro-environment for the embryo's rapid and dramatic morphological changing process at the peri-implantation stage.

• International Journal of Oral Biology
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• v.34 no.4
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• pp.177-183
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• 2009

Human mesenchymal stem cell (hMSCs) isolated from human adult bone marrow have self-renewal capacity and can differentiate into multiple cell types in vitro and in vivo. A number of studies have now demonstrated that MSCs can differentiate into various neuronal populations. Due to their autologous characteristics, replacement therapy using MSCs is considered to be safe and does not involve immunological complications. The basic helix-loop-helix (bHLH) transcription factor Olig2 is necessary for the specification of both oligodendrocytes and motor neurons during vertebrate embryogenesis. To develop an efficient method for inducing neuronal differentiation from MSCs, we attempted to optimize the culture conditions and combination with Olig2 gene overexpression. We observed neuron-like morphological changes in the hMSCs under these induction conditions and examined neuronal marker expression in these cells by RTPCR and immunocytochemistry. Our data demonstrate that the combination of Olig2 overexpression and neuron-specific conditioned medium facilitates the neuronal differentiation of hMSCs in vitro. These results will advance the development of an efficient stem cell-mediated cell therapy for human neurodegenerative diseases.

• Parasites, Hosts and Diseases
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• v.50 no.1
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• pp.83-87
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• 2012

To determine the effects of kimchi extracts at different temperatures on larval development, $Ascaris$ $suum$ eggs were mixed with soluble part of 7 different brands of commercially available kimchi and preserved at either $5^{\circ}C$ or $25^{\circ}C$ for up to 60 days. $A.$ $suum$ eggs incubated at $25^{\circ}C$ showed marked differences in larval development between kimchi extract and control group. While all eggs in the control group completed embryonation by day 21, only 30% of the eggs in the kimchi extract group became embryonated by day 36 and about 25% never became larvated even at day 60. At $5^{\circ}C$, however, none of the eggs showed larval development regardless of the incubation period or type of mixture group. To determine the survival rate of $A.$ $suum$ eggs that showed no embryonation after being preserved at $5^{\circ}C$, eggs preserved in kimchi extracts for 14, 28, and 60 at $5^{\circ}C$ were re-incubated at $25^{\circ}C$ for 3 weeks in distilled water. While all eggs in the control group became larvated, eggs in the kimchi extract group showed differences in their embryonation rates by the incubation period; 87.4 % and 41.7% of the eggs became embryonated after being refrigerated for 14 days and 28 days, respectively. When refrigerated for 60 days, however, no eggs mixed in kimchi extract showed larval development. Our results indicate that embryogenesis of $A.$ $suum$ eggs in kimchi extract was affected by duration of refrigeration, and that all eggs stopped larval development completely in kimchi kept at $5^{\circ}C$ for up to 60 days.