• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.24-25
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• 2003

The zebrafish (Danio rerio) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. I will talk about positional cloning of two developmental mutants in zebrafish. The first mutant is headless: The vertebrate organizer can induce a complete body axis when transplanted to the ventral side of a host embryo by virtue of its distinct head and trunk inducing properties. Wingless/Wntantagonists secreted by the organizer have been identified as head inducers. Their ectopic expression can promote head formation, whereas ectopic activation of Wnt signalling during early gastrulation blocks head formation. These observations suggest that the ability of head inducers to inhibit Wntsignalling during formation of anterior structures is what distinguishes them from trunk inducers that permit the operation of posteriorizing Wnt signals. I describe the zebrafish headless (hdl) mutant and show that its severe head defects are due to a mutation in T-cell factor-3 (Tcf3), a member of the Tcf/Lef family. Loss of Tcf3 function in the hdl mutant reveals that hdl represses Wnt target genes. I provide genetic evidence that a component of the Wntsignalling pathway is essential in vertebrate head formation and patterning. Second mutant is mind bomb: Lateral inhibition, mediated by Notch signaling, leads to the selection of cells that are permitted to become neurons within domains defined by proneuralgene expression. Reduced lateral inhibition in zebrafish mib mutant embryos permits too many neural progenitors to differentiate as neurons. Positional cloning of mib revealed that it is a gene in the Notch pathway that encodes a RING ubiquitin ligase. Mib interacts with the intracellular domain of Delta to promote its ubiquitylation and internalization. Cell transplantation studies suggest that mib function is essential in the signaling cell for efficient activation of Notch in neighboring cells. (중략)

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.100-100
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• 2003

Pluripotent embryonic stem (ES) cells differentiate spontaneously into beating cardiomyocytes via embryo-like aggregates. We describe the use of mouse embryonic stem (mES03) cells as a reproducible differentiation system for cardiomyocyte. To induce cardiomyocytic differentiation, mES03 cells were dissociated and allowed to aggregate (EB formation) at the presence of 0 75% dimethyl sulfoxide (DMSO) for 4 days and then another 4 days without DMSO (4+/4-). Thus treated EBs were plated onto gelatin-coated dish for differentiation. Spontaneously contracting colonies which appeared in approximately 4-5 days upon differentiation. Expression of cardiac-specific genes were determined by RT-PCR. Rebust expression of myosin light chain (MLC-2V), cardiac myosin heavy chain $\alpha$, cardiac muscle heavy polypeptide 7 $\beta(\beta$-MHC), cardiac transcription factor GATA4 and skeletal muscle-specific ${\alpha}_1$-subunit of the L-type calcium channel (${\alpha}_1 CaCh_{sm}$) were detected as early as 8 days after EB formation, but message of cardiac muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel (${\alpha}_1$CaCh) were revealed at a low level. Strikingly, the expression of atrial natriuretic factor (ANF) was not detected. When spontaneous contracting cell masses were examined their electrophysiological features by patch-clamp technique, it showed ventricle-like action potential 17 days after the EB formation. This study indicates that mES03 cell-derived cardiomyocytes displayed biochemical and electrophysiological properties of cardiomyocytes and DMSO enhanced development of cardiomyocytes in 4+/4- method.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.781-787
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• 2009

The sense and antisense digoxigenin-labeled RNA probes of four genes, Cdc25A, Cdc25B, Sox2 and Mnb, were produced by using SP6 and T7 RNA polymerases, respectively, and in vitro transcription. Expression patterns of the four genes were detected by in situ hybridization in HH (Hamburger and Hamilton) stage 10 chick embryos. In general, expression patterns of the four genes were similar. mRNA of the four genes was mostly restricted to the entire CNS (central nervous system). All were confined to an identical region, neural tube, neural groove and caudal neural plate, corresponding to the notochord or spinal cord, but there was some distinction in specific region or in concentration, for example in somites. The overlap in expression at the same developmental stage in the CNS suggests that the four genes may be functional similar or related in CNS development. Expression patterns of the four genes support specific roles of these regulators in the developing CNS.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.197-204
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• 2019

This study was investigated to test whether the zygote recognized the topoisomerase II beta (TOP2B) mediated DNA fragmentation in epididymal spermatozoa or the nuclease degradation in vas deferens spermatozoa by testing for the presence of gammaH2AX (γH2AX). The γH2AX is phosphorylation of histone protein H2AX on serine 139 occurs at sites flanking DNA double-stranded breaks (DSBs). The presence of γH2AX in the pronuclei of mouse zygotes which were injected with DNA broke epididymal spermatozoa was tested by immunohistochemistry at 5 and 9 h post fertilization, respectively. Paternal pronuclei that arose from epididymal spermatozoa treated with divalent cations did not stain for γH2AX at 5 h. On the other hand, in embryos injected with vas deferences spermatozoa that had been treated with divalent cations, γH2AX was only present in paternal pronuclei, and not the maternal pronuclei at 5 h. Interestingly, both pronuclei stained positively for γH2AX for all treatments and controls at 9 h after sperm injection. In conclusion, the embryos recognize DNA that is damaged by nuclease, but not by TOP2B because H2AX in phosphorylated in paternal pronuclei resulting from spermatozoa treated with fragmented DNA from vas deferens spermatozoa treated with divalent cations, but not from epididymal spermatozoa treated the same way.

• Journal of Animal Science and Technology
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• v.53 no.3
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• pp.269-274
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• 2011

DNA methyltransferases (DNMTs) are closely associated with the epigenetic change and the gene silencing through the regulation of methylation status in animal genome. But, the role of DNMTs in transgene silencing has remained unclear. So, we examined whether the knockdown of DNMT influences the reactivation of transgene expression in the transgenic quails. In this study, we investigated the expression of DNMT3a, and DNMT3b in blastoderm, quail embryonic fibroblasts (QEFs) and limited embryonic tissues such as gonad, kidney, heart and liver of E6 transgenic quails (TQ2) by RT-PCR. We further analyzed the expression of DNMT3a at different stages of whole embryos during early embryonic development by qRT-PCR. DNMT3a expression was detected in all test samples; however, it showed the highest expression in E6 whole embryo. Embryonic fibroblasts collected from TQ2 quails were treated with two DNMT3a-targeted siRNAs (siDNMT3a-51 and siDNMT3a-88) for RNA interference assay, and changes in expression were then analyzed by qRT-PCR. The siDNMT3a-51 and siDNMT3a-88 reduced 53.34% and 64.64% of DNMT3a expression in TQ2 QEFs, respectively. Subsequently the treatment of each siRNA reactivated enhanced green fluorescent protein (EGFP) expression in TQ2 (224% and 114%). Our results might provide a clue for understanding the DNA methylation mechanism responsible for transgenic animal production and stable transgene expression.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.632-637
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• 2006

Oviduct-specific glycoprotein 1 (OVGP1) is implicated in playing a role in fertilization and early embryo development. In this study, we have obtained the sequence of intron 9 of OVGP1 gene in swine. Comparative sequencing of Meishan (a native Chinese breed) and Large White pig breeds revealed an A/T substitution at position 943. A PCR-EcoRI-RFLP assay was developed to detect this mutation. Polymorphism analysis in Qingping animals showed that pigs with BB genotype had lower number of piglets born alive (NBA) in multiple parities than pigs with AA (p<0.05) and AB genotype (p<0.01). In Large $White{\times}Meishan$ ($LW{\times}M$) $F_2$ offspring, the weight of both ovaries (OW) of the BB genotype was significantly lighter than that of AB (p = 0.05) and AA (p<0.01) genotypes. Analysis of the data also revealed that the mutation locus affected these two traits mostly by additive effects. These studies indicated that the polymorphism was associated with NBA and OW in two distinct populations and further investigations in more purebreds or crossbreds are needed to confirm these results.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.842-849
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• 2007

The purpose of the present study was to produce live offspring from in vitro fertilized goat embryos. Oocytes were collected from abattoir ovaries and kept in oocyte collection medium. Oocytes were washed 4-5 times with maturation medium containing medium-199 with 5 ${\mu}g/ml$ FSH, 100 ${\mu}g/ml$ LH, 1 ${\mu}g/ml$ estradiol-$17{\beta}$ 50 ${\mu}g/ml$ gentamycin, 10% inactivated estrus goat serum, and 3% BSA (fatty acid free). Oocytes were placed in 100 ${\mu}l$ drops of maturation medium containing granulosa cell monolayer and incubated in a 5% $CO_2$ incubator at $38.5^{\circ}C$ for 27 h. For capacitation of spermatozoa fresh semen was processed and mixed in 3 ml fertilization TALP medium containing 50 ${\mu}g/ml$ heparin and kept in the above incubator for 2 h. The capacitated spermatozoa were coincubated with matured oocytes for fertilization. Cleaved embryos were separated and cultured in embryo development medium with oviductal cells and 494 embryos were produced. Recipient goats were synchronized with two injections of 15 mg $PGF_{{2}{\alpha}}$/goat 10 days apart. Eighty early stage embryos were transferred into the uterotubal junction of 14 surrogate mothers using laparoscopy techniques. One recipient delivered twin kids, whereas another two recipients each.delivered a single kid The parentage of these kids was evaluated using highly polymorphic co-dominant microsatellites markers. From the present study, it was concluded that live goat kids can be produced from in vitro matured and fertilized goat embryos, to the best of our knowledge for the first time in India.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1407-1413
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• 2009

The present study was conducted to gain insights into oocyte maturation and early embryo development, SELDI-TOF-MS was used to find the protein candidates that are specifically or prominently expressed in mouse oocytes at the in vitro matured metaphase II (MIl) and germinal vesicle (GV) stages. By using selected CM10 chip, found 16 candidates which were up-regulated in GV stage oocytes compared with in MIl stage oocytes, molecular weight are 8180 (2 candidates), 10226 (5 candidates), 15767 (5 candidates) and 16770 (4 candidates) Da respectively. And 29 candidates were higher in MIl than in GV stage oocytes, molecular weight are 10832 (3 candidates), 17744(8 candidates), 20122 (3 candidates), 22131 (3 candidates), 24857 (7 candidates) and 33507 (5 candidates) Da, respectively. All (45) candidate (0.2 and 1.0 % error tolerances) were performed real time RT-PCR analysis and further selected 13 more potential candidates.

• Molecules and Cells
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• v.40 no.12
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• pp.945-953
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• 2017

We report the biological functions of a zebrafish homologue of RING-finger protein 152 (rnf152) during embryogenesis. rnf152 was initially identified as a brain-enriched E3 ligase involved in early embryogenesis of zebrafish. Expression of rnf152 was ubiquitous in the brain at 24 hpf but restricted to the eyes, midbrain-hindbrain boundary (MHB), and rhombomeres at 48 hpf. Knockdown of rnf152 in zebrafish embryos caused defects in the eyes, MHB, and rhombomeres (r1-7) at 24 hpf. These defects in rnf152-deficient embryos were analyzed by whole-mount in situ hybridization (WISH) using neuroD, deltaD, notch1a, and notch3 probes. NeuroD expression was abolished in the marginal zone, outer nuclear layer (ONL), inner nuclear layer (INL), and ganglion cell layer (GCL) of the eyes at 27 hpf. Furthermore, deltaD and notch1a expression was remarkably reduced in the ONL, INL, subpallium, tectum, cerebellum, and rhombomeres (r1-7) at 24 hpf, whereas notch3 expression was reduced in the tectum, cerebellum, and rhombomeres at 24 hpf. Finally, we confirmed that expression of Notch target genes, her4 and ascl1a, also decreased significantly in these areas at 24 hpf. Thus, we propose that Rnf152 is essential for development of the eyes, midbrain and hindbrain, and that Delta-Notch signaling is involved.

• Archives of Pharmacal Research
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• v.17 no.4
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• pp.209-212
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• 1994

Mophological normal of unfertilized oocytes, which was collected 12-14 hours after human Chorionic Gonadotropin(jCG) injection, was not influenced by chronically adiministration of cocaine for 2 weeks in mice. Proportion of normal unfertilized oocytes in non-cocaine treated group (control), `0 mg/kg and 20 mg/kg cocaine treated group based on body weight with subcutaneous(s.c.) daily injection of cocaine for 2 weeks were 92.9%, 85.6% and 90.9%, respectively. There is no significant difference between control and cocaine treated groups. Two to 8 cell stage embryos collected 24-48 hours post hCG in control group were 66.7%, whereas, 10 mg/kg and 20 mg/kg groups treated with cocaine was 12.5% and 27.3% respectively. Although control and treated groups are significantly different (p<0.05) the developmental score of 2 to 8 cell stage embryos collected at 24-48 hours post HCG, there is no difference between 10 mg/kg and 20 mg/kg treated with cocaine groups. These results indicated that the normal embryos of the roups of cocaine administration were significantly amested when compared with that of control group. The proportion of 2 to 8 cell stage embryo reaching the blastocyst stage, which were cultured 48-52 hours with 5% $Co_2$ in air at $37^{\circ}C$, were 93.9% in control group and, 70.4% and 71.9% in each 10 mg/kg and to blastocyst in vitro culture was significantly limited embryos obtained from cocanized mice compared with those of control mice. These results suggest that episode of cocaine intoxication can cause impaiment of early embrygenesis in the mouse.