• Clinical and Experimental Reproductive Medicine
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• v.27 no.4
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• pp.345-351
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• 2000

Objective: Hatching of the blastocyst from the zona pellucida (ZP) is a key event in mammalian implantation. In vivo, two factors have been identified as possible mediators of hatching: lysis of the ZP by substances elaborated either from the embryo or female reproductive tract and pressure exerted on the zona by expansion of the blastocyst. Two methods of zona manipulation were already in use to enhance the ability of embryos to hatch: mechanical PZD and chemical ZD by acidic Tyrode's solution. But several controversies of each method have been reported. The purpose of this study was to investigate the effect of pronase for mouse embryo hatching. Methods: Mouse embryos were obtained following ovulation induction of $F_1$ animals. Fresh and cryo-thawed morula embryos were exposed to 0.5, 1.0, 2.0, 5.0 ${\mu}g/ml$ pronase in Ham's F10 for 72 hrs. Main outcome measures were the rates of partial hatching and completely hatched blastocysts, and cell number of it. Results: In fresh and cryo-thawed group, the rates of completely hatched blastocyst were significantly higher in 5 ${\mu}g/ml$ pronase treatment group than control group. There was no difference in completely hatched blastocyst total cell number between pronase treatment group and control group. This suggest that pronase treatment did not harmful in mouse embryo development. In pronase treatment group, zona pellucida were thinner than control group. Conclusion: The addition of pronase to culture media may accelerate the hatching of embryo. So, enzymatic treatment of the zona may provide a valuable and effective assisted hatching technique for human in-vitro fertilization-embryo transfer.

• Journal of Embryo Transfer
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• v.17 no.3
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• pp.211-218
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• 2002

These studies were carried out to investigate the effects of the addition of amino acids and FBS as source of exogenous nitrogen fixation added to medium on in vitro production of blastocyst derived from bovine follicular oocytes. The base medium was TCM-199 solution for in vitro maturation(IVM) of bovine follicular oocytes and Fer-TALP solution for in vitro fertilization(IVF) and YS solution for in vitro culture(IVC). IVC used the fertilized oocytes of 24-hr culture (day 1) after IVF. Rmbryos were cultured in drop-culture that contained 25 embryos per 10 ${mu}ell$. The results obtained are as follows: 1 The developmental rates of fertilized oocytes to blastocyst that developed from YS solution with NEAA derived from MEM alone were higher than those of YS solution without NEAA. 2. The developmental rates of fertilized oocytes to blastocyst that developed from YS solution with EAA derived RPMI 1640 alone were significantly higher than those of YS solution without EAA (p<0.05). 3. When added to EAA on day 5 after NEAA supplementation on day 1, the developmental rates of hatched blastocyst and blastocyst to hatched blastocyst were improved. 4. When removed to EAA on day 3, day 4 and day 5 from medium after NEAA and EAA supplementation on day 1. the developmental rates of blastocyst to hatched blastocyst were reduced. 5. When added to FBS as source of exogenous nitrogen fixation, the developmental rates of blastocyst and hatched blastocyst that developed from the later culture higher(day 5) than those of the early culture.

• Journal of Aquaculture
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• v.12 no.1
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• pp.31-38
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• 1999

The dietary value and fatty acids composition for the hatched neonates from the resting eggs of marine roofers, Brachionus plicatilis and B. rotundiformis were compared with that for mass-cultured rotifers (control) by feeding them to larvae of flounder (Paralichthy olivaceus) and parrot fish (Oplegnathus fasciatus). Resting eggs were mass-produced in $1~4m^3$tanks by feeding Chlorella sp. and baker's yeast. The B. plicatilis and B. rotundiformis eggs were preserved at $5^{\circ}C$ in darkness for 3 and 5 months, respectively, and hatched at $28^{\circ}C$ under continuous light. The hatched neonates from the resting eggs and mass-cultured rotifer, which was used as a rontrol were fed to fish larvaes. The growth and survival rates of parrot fish larvae fed on the neonates from the resting eggs of B. rotundiformis were similar to those of fish larvae fed on the control rotifer. And the growth and survival rates of the flounder larvae with neonates from the resting eggs of B. plicatilis were similar or higher than those fed the control rotifer. Also the fatty acids composition of the neonates from the resting eggs of B. plicatilis and B. rotundiformis were similar to those from the control rotifers. This results showed that the hatched neonates from resting eggs of rotifer could be used as an effective diet for flounder and parrot fish larvae.

• Bulletin of the Korean Chemical Society
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• v.29 no.6
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• pp.1179-1184
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• 2008

Commercial nanometer sized silver is widely used for its antibacterial effect; however, nanoparticles may also have ecotoxicological effects after being discharged into water. Nanometer sized silver can flow into aquatic environments, where it can exert a variety of physiologically effects in living organisms, including fish. The present study aimed to investigate the effect of nanometer sized silver on the development of zebrafish embryos, analyze the properties of commercial nanometer sized silver and define the toxicity relationship between embryogenesis and hatched flies. The commercial nanometer sized silver was analyzed in the $Ag^+$ ion form. The hatch rate decreased in the nano-silver exposed groups (10 and 20 ppt); furthermore, the hatched flies had an abnormal notochord, weak heart beat, damaged eyes and curved tail. The expression of the Sel N1 gene decreased in the nano-silver exposed groups, and the catalase activities of the exposed groups increased relative to those in the control group. Therefore, the $Ag^+$ ions in commercial nanometer sized silver could accumulate in aquatic environments and seriously damage the development of zebrafish embryos.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.3
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• pp.152-156
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• 2016

Objective: We studied the effect of the site of laser zona opening on the complete hatching of mouse blastocysts and the cell numbers of the completely hatched blastocysts. Methods: Mouse blastocysts were randomly allocated to the inner cell mass (ICM) group (zona opening performed at the site of the ICM, n=125), the trophectoderm (TE) group (zona opening performed opposite to the ICM, n=125) and the control group (no zona opening, n=125). Results: The rate of complete hatching of the blastocysts was not significantly different in the ICM and the TE group (84.8% vs 80.8%, respectively; p=0.402), but was significantly lower in the control group (51.2%, p<0.001). The cell numbers in the completely hatched blastocysts were comparable in the control group, the ICM group, and the TE group ($69{\pm}19.3$, $74{\pm}15.7$, and $71{\pm}16.8$, respectively; p=0.680). Conclusion: These findings indicate that the site of laser zona opening did not influence the rate of complete hatching of mouse blastocysts or their cell numbers.

• Animal Systematics, Evolution and Diversity
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• v.18 no.2
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• pp.191-201
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• 2002

The first zoeal stage of Heptacarpus rectirostris (Stimpson, 1860) is re-described and illustrated in detail from laboratory-hatched material. The first zoea of H. rectirostris is more closely related to that of H. futilirostris than to H. camtschaticus, H. pandaloides, and H. geniculatus by having the pterygostomial spine and two anteroventral denticles on the carapace. The former two species, however, can be readily distinguished by the presence (H. futilirostris) or absence (H. rectirostris) of the posterolateral spine on the abdominal somites 4-5. A provisional key to the first zoeas of Heptacarpus for which larval studies are known from Korea and adjacent waters is provided. A list of larval descriptions within the Hippolytidae from Korea and adjacent waters is also included.

• Animal Systematics, Evolution and Diversity
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• v.18 no.2
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• pp.181-189
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• 2002

The first zoeal stage of Palaemon ortmanni (Rathbun, 1902) is re-described and illustrated in detail from laboratory-hatched material. The first zoeas of Palaemon are more closely related to those of Palaemonetes than to Macrobrachium, Leptocarpus, Leander, Leanderites, and Brachycarpus by having the endopod of maxillule with terminal seta and the endopod of maxilla with 2+1 setae. A provisional key to the zoeas between three genera Palaemon, Macrobrachium, and Periclimenes known from Korean waters is included.

• Development and Reproduction
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• v.17 no.3
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• pp.247-255
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• 2013

The gonadsomatic index (GSI) of mottled skate was the highest in April, GSI and HSI showed a reverse phase for its reproductive cycle. The fish had one pair of egg capsules, having 1 to 7 fertilized eggs, and spawned all the year round. When surveying the reproductive characteristics of females over 63 cm in disc width, we found the spawning peak was between April to June, and the appearance ratio of egg capsules was the highest in May (32.1%). The eggs were hatched at $8^{\circ}C$, $13^{\circ}C$, $18^{\circ}C$, water temperature (12.8 to $24.2^{\circ}C$), and the best hatching temperature was $18^{\circ}C$. The number of fish hatched was 4 to 5 fish/egg capsules, and the hatching rate was 100%. The sex ratios of hatching larvae were 45.5% female and 54.5% male. Therefore this study will provide fundamental data and information for artificial reproduction of the mottled skate.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.193-199
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• 2010

We report here the production of transgenic chickens that can regulate human erythropoietin (hEPO) gene expression. The glycoprotein hormone hEPO is an essential for viability and growth of the erythrocytic progenitors. Retrovirus vector system used in this study has two features including tetracycline-controllable promoter and woodchuck hepatitis virus posttranscriptional regulator element (WPRE). The former is for to reduce the possibility of physiological disturbance due to constitutional and unregulated expression of hEPO gene in the transgenic chicken. The latter is for maximum expression of the foreign gene when we turn-on the gene expression. A replication-defective Moloney murine leukemia virus (MoMLV)-based vectors packaged with vesicular stomatitis virus G glycoprotein (VSV-G) was injected beneath the blastoderm of non-incubated chicken embryos (stage X). Out of 325 injected eggs, 28 chicks hatched after 21 days of incubation and 16 hatched chicks were found to express the hEPO gene delivered by the vector. The biological activity of the recombinant hEPO in transgenic chicken serum was comparable to its commercially available counterpart. The recombinant hEPO in transgenic chicken serum had N- and O-linked carbohydrate simillar to that produced from in vitro cultured cells transformed with hEPO gene.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.203-208
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• 2020

This study was carried out to clarify the larvae and juveniles of egg development and autonomous development of Hemibarbus longirostris from Korea, and to obtain basic data for species conservation and seed production. The shape of the egg was circular and sticky. The average size of the eggs was 2.01 mm (n=10). At 185 hours after fertilization, more than 50% of the total embryos were hatched. The newly hatched larvae had an average total length of 8.10 mm (n=5) and had egg yolk in the abdomen. At 3 days after hatching, the larvae absorbed all egg yolk was average total length 8.64 mm. On the 6 days after hatching, the caudal tip of the notochord started to curve upwards was average total length 10.9 mm. At 70 days after hatching, the average total length 37.9 mm. The number of fins was i 8-10 in dorsal fin, iii 7 in the anal fin, and ii 5 in the ventral fin.