• Korean Journal of Poultry Science
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• v.23 no.1
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• pp.9-17
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• 1996

This study was conducted to compare the survival rate of chick embryos among different eggshell window positions and to search for the most appropriate injection position. The eggshells were punctured at blunt-end, sharp-end and side-up with a sterilized fine forceps, respectively. The survival rate of sharp-end window was higher than the other window positions. Injection of Dulbecco’s modified eagle’s medium (DMEM) through blunt-end window (BE1) was impossible because inner cell membrane was obscure. The 2 ${\mu}$L DMEM was injected into 2.5 d-old embryo blood vessel through sharp end window. To prevent hemorrhages at the point of injection, the air bubbles were injected into the embryo blood vessel. The survival rate of chicks embryo in sharp end window was about 17.0％. Therefore, this sharp-end window system will be helpful for the production of germline chimera or transgenic chicken using primordial germ cells ( PGCs ).

• BMB Reports
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• v.31 no.4
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• pp.350-354
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• 1998

To understand the role of protein kinase C (PKC) in the regulation of chondrogenesis, we examined proteins which are phosphorylated by PKC. Stage 23/24 chick embryo wing mesenchymes were micromass-cultured to induce chondrogenesis and cell extracts were phosphorylated in a condition that activates PKC. Several proteins including 63 and 66 kDa proteins were phosphorylated. The 66 kDa protein was phosphorylated only in the presence of phorbol 12-myristate 13-acetate (PMA) and phosphatidylserine CPS), and the phosphorylation was almost completely diminished by bisindolylmaleimide, a PKC inhibitor. In addition, partially purified PKC increased the phosphorylation of the 66 kDa protein. Treatment of cultures with lysophosphatidylcholine (LPC) promoted chondrogenesis and phosphorylation of 66 kDa protein, while PMA and thymeleatoxin inhibited both of the two events. Our results suggest that the 66 kDa protein is a putative substrate of PKC, and phosphorylation of the 66 kDa protein, probably by $PKC\alpha$ is required for chondrogenesis.

• Applied Microscopy
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• v.24 no.2
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• pp.26-36
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• 1994

To investigate the effects of mercuric chloride ($HgCl_2$) on the differentiation in the cerebral neuron of chick embryo 7 days, the ultrastructural changes in nerve cells injected with a various doses of mercuric chloride were observed with transmission electron microscope. The enzyme activity of the some dehydrogenases, and adenosine triphophate (ATP) were also analyzed. The results obtained are as follows; The ultrastructural changes in 1.0mg-injected group, the nuclear envelope were irregular, and the RER, Golgi complexes and mitochondria were not well developed. In 2.0mg-injected group, the nuclear envelope were partly destroyed or detached, and mitochondria were decreased in number and their cristae were destroyed, too. The RER and Golgi complexes were less developed than those of the normal groups. In general, the activities of dehydrogenases were declined by increasing the dose of mercuric chloride. Lactate dehydrogenase (LDH) activity fatted to below 85% of the normal group in 1.0mg-injected group, and 69% in 2.0mg-injected group. Malate dehydrogenase (MDH) activity was decreased greatly to 76% in 2.0mg-injected group. Succinate dehydrogenase (SDH) activity fatted to 85% in 1.0mg-injected group, and 74% in 2.0mg-injected group. ATP content in 1.0mg-injected group was almost near to the normal level, but it was increased significantly in 2.0mg-injected group.

• The Korean Journal of Zoology
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• v.34 no.4
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• pp.460-468
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• 1991

계배 limb bud간충직 연골원성 세포로부터 연골원세포로의 분화과정에서 Ca2+의 역할을 추구해 보기 위하여 Hamburger-Hamilton stage 23/24의 계배 limb bud간충직세포들을 미세배양법으로 배양하면서, Ca2+, calcium ionophore인 A23187, calcium channel blocker인 D600을 각각 농도 및 처리기간을 변화시켜 처리하면서 연골화의 정도를 검정하여, 연골세포 분화에 미치는 Ca2+의 작용양상을 분석하였다. 그 결과 Ca2+은 3 mM의 농도로 배양초기에 처리하였을 때 가장 효과적으로 연골화를 촉진하였으며, A23187(0.05 $\mu$ M) 처리는 세포내로 Ca2+유입을 증가시켜 연골화를 촉진시킨 반면, D6OO(30 $\mu$ M이하) 처리는 세포내로 Ca2+ 유입을 차단시킴으로서 연골화를 억제하는 것으로 나타났다. 이러한 결과에 따른 세포내로의 칼슘 유입 변화는 45Ca로 확인하였다. 그러므로 Ca2+에 의한 간충직세포의 연골세포로의 분화촉진 작용은 Ca2+이 연골화의 응집시기에 세포간의 접촉을 유도할 뿐만 아니라 배양 초기에 Ca2+이 세포 내로 들어감으로써 수반되는 일련의 기작에 의한 것임을 알았다.

• Applied Microscopy
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• v.20 no.1
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• pp.17-35
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• 1990

Effect of 5-hydroxytryptamine(5-HT, serotonin) and its precursor tryptophan on the cell proliferation of brain and somite parts of 4 day chick embryo in Dulbeco's modified essential medium was examined morphologically at cellular level. It was realized that the externally added 5-HT and/or tryptophan disturbed cell proliferation and severve necrosis occured. Electron micrograph showed that the development of cell organelles were greatly impaired. The activities of both acetylcholine esterase and $Mg^{2+}$ -dependent ATPase of the brain tissues of 5 day chick embryo, which received 1mg of tryptophan and/or 0.1mg of 5-HT at primitive streak stage after 24 hrs incubation of the fertilized egg, were much lower(about 20-25%) than those of control group. These results were supported by the electron micrographs of chemically treated cells. Control cells showed clear densed bands of acetylcholine esterase activity around nucleus and rough endoplasmic reticulum but tryptophan or 5-HT treated groups showed discontinued activity bands. In the case of $Mg^{2+}$-ATPase, the control groups showed clear continuous activity bands but tryptophan and/or 5-HT treated groups were discontinuous. From the previous and present studies, it seems that the intracelluar 5-HT level is very important for the cell proliferation and normal morphogenesis.

• Applied Microscopy
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• v.27 no.1
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• pp.87-100
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• 1997

To investigate the effects of mercuric chloride $(HgCl_2)$ on the differentiation of the cerebral neuron of chick embryo 10 days, the ultrastructural changes in nerve cells injected with a various doses of mercuric chloride were observed with transmission electron microscope. The enzyme activity of the some dehydrogenases, cerebral proteins and adenosine triphosphate (ATP) were also analyzed. The results obtained are as follows; The ultrastructural changes in 1.0 mg-injected group, the nuclear membranes were irregular, outer of mitochondria membrances dispressioned, their cristae were destroyed. In 2.0 mg-injected group, the nuclear envelops were destroyed and divided, were not observed organelle except of few ribosome, the RER and mitochondria. The number of polypeptide bands were separated by SDS-PAGE in the normal group were 38 bands. According to the in creased dose of mercuric chloride, contends of the bands were increased in 4 bands, but were decreased in 1 band. The activities of dehydrogenases were declined by increasing the dose of mercuric chloride. Lactate dehydrogenase (LDH) activity fatted to 61% in 2.0 mg-injected group. Malate dehydrogenase (MDH) activity fatted to 90% in 1.0 mg-injected group, greatly to 76% in 2.0 mg-injected group. Succinate dehydrogenase (SDH) activity decreased to 79% in 1.0 mg-injected group and greatly to 62% in 2.0 mg-injected group. ATP content in 1.0 mg-injected group was almost near to the normal level, but it was increased greatly in 2.0 mg-injected group.

• The Korean Journal of Zoology
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• v.8 no.2
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• pp.37-41
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• 1965

The frequency and pattern of sex chromatin in primary cultured cells of kidney cortex of cats and guinea-pigs, and muscle of chick embroys were examined and compared to those of in vivo condition, with special reference to the various cultured stages. 1. In cat, the frequencies of sex chromatin positive I of peripheral position were average 62.7% in female, and 15% in male, whereas those of non-peripherla position were 5.8% in female and 0.1% in male. The incident proportion between them showed a marked difference-approximately 10 times higher in female than male. These results failry indicated that a distinct nuclear dimorphism with regard to the sex chromatin positive I was established in cultured cells. The position of sex chormatin was usually peripheral location. The tendency of frequencies , with reference to the cultured stages, was low count in primary extracted and initial stage cells , but it showed a peaked frequency in 10-13 days after primary culture, and after that the frequencies were decreased gradually. Compared between I vitro and in vivo condition of the same tissues, the cells in vivo exhibited the sex chromatin in high frequency at the peak showed stage. 2. In guinea-pig , the frequencyies of peripheral positive I were 36.8% in female and 6.3% in male, while non-peripheral positions were 6.1% in female and 3.5% inmale. Its incident was a rate of nearly 4 times higher in female than male. The nuclear dimorphism was also established in cultrued cells of guinea-pig. The position and the incident frquency showed a similar pattern as in cat except the primary extracted cells. 3. In chick embryo, the frequencies of sex chromatin positive I of peripheral position were 38.2% in female, and 18.3% in male, non-peripheral position, however, was hardly to find. These results suggest that the definite sexual dimorphism was unable to find in chick embryo cultured cells. The position and the incident tendency were a similar pattern as in above mammals and the frequency was higher in vitro cells.

• Journal of Life Science
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• v.19 no.9
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• pp.1309-1313
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• 2009

Endocrine disruptors are chemicals which can be found in our normal daily lives. Chemicals such as bisphenol A, DDT, benzophenone and phenylphenol can be easily ingested through plastic food containers and pesticides. Endocrine disruptors can be very harmful and toxic because they disrupt the normal function of the endocrine system. It has been reported that endocrine disruptions can cause fatal strikes in the cardiovascular, reproductive, and central nervous systems, and other parts of the body. Therefore we examined if benzophenone as an endocrine disruptor inhibits development in or induces malformation of chick embryos. Chick embryos which received a single injection of benzophenone ($1{\mu}g$/egg $\sim$ $500{\mu}g$/egg) via the yolk sac at designated times (6, 9, 12, 15, 18 and 21 days after incubation) were investigated. Body weight reduction was observed in middle doses ($40{\mu}g$/egg $\sim$ $60{\mu}g$/egg). High mortality rates and teratogenic signs such as abnormal wry beak and abnormal eyeballs were seen in high doses ($80{\mu}g$/egg $\sim$ $500{\mu}g$/egg). In conclusion, it is suggested that benzophenone induces malformation of chick embryos and seriously inhibits development.

• The Korean Journal of Zoology
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• v.38 no.2
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• pp.286-293
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• 1995

The present studies were undertaken to examine the activitites of PKC isoforms in cultures of chick limb mesenchvme. Micromass cultures were prepared using wing buds of stage 23/24 (Hamburger and Hamilton, 19511 chick embryo. The cells were homogenized and DEAE-cellulose column chromatography was performed to get fraction containing protein kinase C (PKC) activity. PKC isoforms were resolved with hvdroxyapatitie column chromatography. Profile of PKC isoforms of cultures were compared with that of rat brain. Activity of $PKC-\beta$ isoform was appeared at the early stage of chondrogenesis. On 3 daw of culture, activities of both PKC a and $\beta$ were observed with remarkable increase but no activity of y isoform was appeared. Treatment of phorbol-12-mvristate-13-acetate (PMA) (10-7 M) to the culture inhibited chondrosenesis and down-regulated a and $\beta$ isoforms. Staurosporine promoted chondro!genesis without any effect on PKC isioforms profile. These data indicate that PKC a and $\beta,$ especiallv $\beta$ isoform is related to chondrosenesis and the promoting effect of staurosporine on chondrogenesis is not related to PKC isoforms activities.

• The Korean Journal of Zoology
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• v.26 no.1
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• pp.1-17
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• 1983

The synthesis of myosin, actin, tropomyosin and troponin in the cultured muscle cells of chick embryo during the differentiation were analyzed. The synthesis of myosin and actin were very active prior to the myoblast fusion while the troponin synthesis became active after the fusion. Tropomyosin was synthesized practically constantly throughout the culture period. Several proteins were detected in the muscle-conditioned medium strongly suggesting that the cells in culture released polypeptides which might act on the membrane of neighboring cells cells to initiate the fusion.