• Journal of Embryo Transfer
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• v.33 no.4
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• pp.343-348
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• 2018

Although the efforts to establish fish embryonic stem cells (ESCs) have been made for a long time, derivation of authentic ESCs that possess pluripotency is still difficult suggesting a need for the stepwise optimization of the methods to establish fish ESCs. Primary culture of the blastomeres from the embryos at blastula stage is a critical step for establishing continuous ESC lines. Here, we evaluated the effects of temperatures and basal media on primary culture of blastula embryo-derived blastomeres in marine medaka (Oryzias dancena). The blastomeres were isolated from the blastula embryos and cultured in various conditions designed by the combination of 4 temperatures including $28^{\circ}C$, $31^{\circ}C$, $34^{\circ}C$, and $37^{\circ}C$ and 2 basal media including Dulbecco's modified eagle's medium (DMEM) and Leibovitz's L-15 medium (L15). With the exception of a case cultured in L15 at $31^{\circ}C$, the rate of primary cell adherence reached 100% when the blastomeres were cultured over $31^{\circ}C$. The period for primary adherence was significantly shorter in the groups cultured in $34^{\circ}C$ and $37^{\circ}C$ than in the ones in $28^{\circ}C$ and $31^{\circ}C$. The proportion of subculture was significantly high in the group cultured in DMEM at $31^{\circ}C$ compared to the other groups. Collectively, we demonstrated that the culture in DMEM at $31^{\circ}C$ was effective to primary culture of the blastomeres derived from blastula embryos.

• Toxicological Research
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• v.11 no.1
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• pp.37-42
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• 1995

Effect of cadmium on the early amphibian development was analyzed through FETAX (Frog Embryo Teratogenesis Assay: Xenopus). Embryos manifested concentration-dependent mortality and realformations; shortage of anterior-posterior axis gut realformation, ocular anomalies, bent notochord, misshapen dorsal fin, and derreal blisters. The treatment with 1.5ppm cadmium solution caused 100% mortality and concentration of lppm did not kill the embryos that caused 100% anomaly. The teratogenic index (TI = LC50 /EC50) was 2.8 indicating that $CdCl_2$ is teratogenic for Xenopus laevis. Embryos that were pulsetreated with at early to late blastula stage (St. 3-9) and mid to late blastula stage (St. 6-10) showed relatively strong resistance to cadmium, but the embryos treated at gastrula stage (St. 10-13) showed high mortality. And the embryos treated at tailbud stage (after St. 25) showed highest mortality of any other early stages. Effects of temperature were studied through pulse- treatment during gastrula stage at $20^{\circ}C$ and $30^{\circ}C$. The embryos treated with 7.5ppm at $30^{\circ}C$ and 15ppm at $20^{\circ}C$ caused 100% mortality respectively, indicating that higher temperature had more severe toxic effect. One of the most peculiar effect of cadmium at gastrulation was distortion of the tail. The probable cause of toxic effect of Cd was discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.894-896
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• 2000

In vitro fertilization can be used for salvaging superior buffalo germplasm which otherwise goes waste after the slaughter of animals. This technology has also increased our basic understanding of growth of germ cells and embryos. The requirement of growing embryos is peculiar and stage specific. In the present study the cleavage and development of buffalo embryos were studied with homologous (buffalo) and heterologous (goat) oviductal cell co-culture systems. The cleavage rate improved significantly (p<0.01) in both homologous and heterologous co-culture as compared to control (55.3, 46.8 and 11.4%). The morula formation using homologous and heterologous oviductal cells also increased significantly as compared to control group (43.6, 21.9 & 1.9%). There was no blastula formation in control group, but addition of oviductal cells either from homologous or heterologous species significantly increased the blastula formation (9.5, 12.5%). The cleavage rate and embryo development was slightly better (non significant) in homologous as compared to heterologous oviductal cell culture. It was concluded that the use of oviductal cell co-culture (homologous and heterologous species) have significantly improved cleavage and development of buffalo embryos in vitro.

• Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.177-185
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• 2013

The development of species-specific fish cell lines has become a valuable tool for biological research. In recent years, marine medaka Oryzias dancena has been recognized as a good experimental model fish but there are no reports of establishment of cell lines from this fish. In this study, two cell lines from O. dancena blastula embryos were established from 41 total trials (4.9%). The two cell lines displayed typical in vitro morphology and have been cultured for >121 passages, which corresponds to 293 days. The doubling times of the cell lines were 29.84 and 28.59 h, respectively, and both possessed the potential to expand in a clonal manner, albeit with significant differences between the two cell lines. The absence of any of the four main medium supplements; i.e., fish serum, fetal bovine serum, basic fibroblast growth factor, and medaka embryo extract, significantly inhibited growth. The proportion of cells possessing normal chromosome number was 45% and 46.7% of the cell lines, respectively. Taken together, two cell lines that proliferate continuously were established from marine medaka and these cell lines may provide a basic tool for characterizing the unique features of this fish species.

• The Korean Journal of Zoology
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• v.31 no.1
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• pp.29-34
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• 1988

In order to investigate the role of nuclei and cytoplasm in early embryogenesis, interspecific nuclear transplantation was carried out Nuclei of one species of amphibian was transplanted into enucleated egg of another species. In interspecific hybrids between Rana species, development was arrested before or right after the dorsal lip formation. In intergenetic hybrids between Rana, Xenopus and axolod, developmental arrest took place at late blastula stage. Comparing the developmental capacity of each nudeocytoplasmic hybrid, the more distantly related the species, the earlier does development arrest. The general rule is that nuclear transfers between any amphibian species will form a regulary cleaved late blastula. Two plausible factors relate to limitation of tite developmental capacity of nudeocytaplasmic hybrids. One is an irreversible change in grafted nuclei and another is tunctional incompatibility between the recipient cytoplasm and transplanted nucleus. The later is postulated a more possible cause of the arrestrnent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.3
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• pp.298-301
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• 2019

We investigated the development of allotriploid embryos derived from a cross between female starry flounder Platichthys stellatus and male stone flounder Kareius bicoloratus. The second cleavage, mid-blastula, gastrula, and Kupffer's vesicle appearance stages, and hatching of embryos began 3.7, 25.6, 45.7, 87.7, and 213.2 h after cold shock at $6^{\circ}C$, respectively. The hatching and development time of triploid interspecific hybrid eggs was approximately the same as those of diploid starry flounder eggs at the same incubation temperature.

• The Korean Journal of Zoology
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• v.28 no.2
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• pp.71-84
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• 1985

Syntheses of RNA and protein were studied to examine changes in activating stored mRNAs during the early development of a sea urchin, Hemicentrotus pulcherimus. The rates of RNA and protein syntheses are very low in the unferilized eggs but the protein synthesis is activated upon the fertilization, while RNA synthesis remains still inactive at the same stage. These rates increase drastically at the blastula and gastrula stages, although the increases are not exactly in parallel. The protein synthesis was found to be also changing in quality during the early development from the studies by the two-dimensional gel electrophoresis.

• The Korean Journal of Malacology
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• v.15 no.2
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• pp.115-119
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• 1999

We investigated the processes of egg and larval developments for aquaculture technique development of seedling production fo the flat oyster, Ostrea denselamellosa. Teo flat oyster of larviparous type was different from the pacific oyser (ovivarous type) because their larvae (trochophore and prodissoconch larvae) in the gill released into the seawater. The process of egg development was observed by artificial fertilization at $25^{\circ}C$, using a dissecting method. The sizes of Unfertilized eggs ranged from 80 to 90 $\mu\textrm{m}$ and fertilized eggs with globule-shape was 90-100 $\mu\textrm{m}$. The Polar body appeared after fertilization and egg cleavage began within 1 hour, reaching the blastula stage after 10 hours. The trochophore in the gill appeared 2-3 days after fertilization and grew to the prodissoconch larvae (130 140 $\mu\textrm{m}$) having a complete shell after 1-2 days. The shell of prodissoconch larvae grew to 205 220 $\mu\textrm{m}$ after 10 hours, and then they became umbo stage larvae showing oval in shape. The velum of umbo stage larvae was degenerated about 17-20 days after fertilization and grew into a pediveliger with a developed foot, at this time, the shell length size was 320 360 $\mu\textrm{m}$.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.1 no.1
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• pp.13-19
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• 1996

Toxicity of surface seawater in Ulsan Bay on a sea urchin, Hemicentrotus pulcherrimus was assessed to investigate the correlation between the concentrations of five heavy metals (Fe, Co, Cu, Cd, and Ni) and the impairments during the developmental stage of the sea urchin eggs. The tests during the six developmental stages of the eggs, are fertilization rate, cell 4, cell 4, polyspermic cleavage, permanent blastula and exogastrula. Highly positive correlations were found between the concentrations of Cu, Co and Ni and the toxicities on the eggs. Such tests will be useful as an indicator of seawater quality.

• Fisheries and Aquatic Sciences
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• v.21 no.2
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• pp.4.1-4.5
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• 2018

Insulin-like growth factors (IGFs), along with IGF-binding protein and IGF receptor, are well-known regulators in the growth and survival of vertebrates. In this study, we investigated the involvement of IGFs and protein variation during embryonic development of the olive flounder (Paralichthys olivaceus). Morphological stages were divided into six main developments as blastula, gastrula, cephalization, cranial regionalization, tail lift, and hatch. During embryonic development, protein variation was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrospray ionization quadrupole time-of-flight mass spectrometry/mass spectrometry. In addition, the mechanism of signaling of IGF-I receptor was examined using immuno-blot analysis. We found marked changes in protein expression at four stages of embryonic development and identified proteins as belonging to the vitellogenin 2 family. As development progresses, expression of IGF-II, phosphotyrosine, and phospho-Akt increased, while expression of growth factor receptor-bound protein 2 (GRB2) and one of guanine-nucleotide-binding proteins (Ras) decreased. These results provide basic information on the IGF system in the embryonic development of the olive flounder.