• International Journal of Industrial Entomology and Biomaterials
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• 제18권2호
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• pp.77-82
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• 2009

The egg shell of the tropical tasar silkworm, Antheraea mylitta is formed from the substances secreted by the follicular epithelium during the late vitellogenic stage. TEM study reveals the inner travecular and outer lamellar layer of chorion. The travecular layer is composed of the innermost wax layer, inner and outer chorionic layer. The inner and outer chorionic layers are connected to each other by vertical pillers forming of cavities. The lamellar layer is perforated by the aeropyles. SEM study reveals the differentiation of an anterior surface of the egg shell into four zones-micropylar, edge, aeropyles crown and disc zone. In the mycosis infected eggs the aeropyles and egg-shell surface are fully packed with the hyphae of the fungus, Aspergillus sydowi blocking of plastron respiration and causing the death of developing embryo so that mycosis infected eggs become sterile.

• 대한수의학회지
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• 제13권2호
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• pp.111-118
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• 1973

The placentation in the golden hamster (Mesocricetus auratus) and the morphological changes occuring in its placenta from implantation to parturition have been observed by light microscope. The results obtained were summarized as follows. 1. The development of the placenta in the fertilized ovum implanted on the day 5 of gestation was described with increasing gestational age. 2. On the day 8 of gestation, the chorioallantoic placenta was formed by fusion of the allantois to the chorion of ectoplacental cone. 3. On the day 13 of gestation, Reichert's membrane with the parietal yolk sac disappeared in a circumscribed area antimesometrially.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권4호
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• pp.194-197
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• 2015

The amniotic membrane is the innermost layer of fetal membrane and is attached to the chorion in the placenta. This membrane has been used for nearly a century in varied fields such as ophthalmology, reconstructive surgery, and burn treatment. In this case report, we used a human amniotic membrane to repair an iatrogenic oroantral communication that occurred during the extraction of the patient's right upper second molar. A splint was given after the perforation was covered with human amniotic membrane and healing was clinically evaluated at various intervals. The outcome of the study revealed that the human amniotic membrane was an efficient graft material for repairing the defect caused by an iatrogenic oroantral communication following tooth extraction.

• 대한수의학회지
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• 제23권1호
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• pp.1-8
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• 1983

The purpose of the present study is to determine variations in synthesis of DNA in the nuclei of various elements of the golden hamster (Mesocricetus auratus) placenta with increasing gestational age from the eighth day post coitus to parturition. The method employed for such determination was autoradiography following injection of pregnant animals with tritiated thymidine. From the results reported, the following points are concluded. The mitotic activities of the endodermal cells of the visceral yolk sac and of the parietal yolk sac, the trophoblastic cells of the labyrinth and the trophospongium and the giant cells were decreased with increasing gestational age, The placentation was nearly completed by day 13 of pregnancy and the increase in size of labyrinth was by appositional growth from the trophospongial cells. It was considered that the inner trophoblastic cells in the vicinity of the fetal blood vessels were originated from the pure chorion. The interrelation among the various cells and the polyploidal giant cells in the placenta were discussed.

• 한국패류학회지
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• 제20권1호
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• pp.55-63
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• 2004

Gonadosomatic index, condition index and reproductive cycle with the gonadal development of the female Octopus ocellatus were investigated by histological observations and morphometric data, from January to December, 2000. And changes in biochemical components of the ovary and the trunk tissues including the digestive organ associated with gonadal development were studied by biochemical analysis from January to October, 2001. The specimens were collected at the coastal waters of Buan, Jeollabuk-do, Korea, from January 2000 to October 2001. O. ocellatus is a dioecious organism. The gonad of O. ocellatus locates medially in posterior region of the body. Morphology of the ovary shows round and oval in shape, the average diameter and external colour of ripe ovary was 32 mm and semitransparent light brown in colour. As the ovary was getting mature, transparent elongated eggs covered with chorion were present in the ovarian cavity. Monthly changes in the gonadosomatic index (GSI) showed a similar pattern with those of the condition index. The GSI and condition index began to increase in March and reached the maximum in April. And then, their values decreased from May and reached the minimum in September. Reproductive cycle of O. ocellatus can be categorized into five successive stages: early developing stage (September to December), late developing stage (November to March), ripe stage (March to May), partially spawned stage (April to June), and degenerative/resting stage (June to October). Follicle cells attached to an oocyte were involved in vitellogenesis in the cytoplasm of the vitellogeneic oocyte and formation of chorion (secondary egg membrane) of the ovarian eggs. Spawning occurred between April and June. The spawning period was once a year and the peak took place between May and June. This species belongs to semelparity. According to changes in biochemical contents of the ovary and the digestive organ, monthly variations of moisture, total protein, total lipid and glycogen contents (%) in the ovary showed a negative correlationship with those of the trunk tissues including the digestive organ. Accordingly, it is assumed that the ovary only may be received nutrient supply (total lipid content) for gonadal development from the trunk tissues including the digestive organ (r = -0.55, p < 0.05).

• Applied Microscopy
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• 제15권1호
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• pp.86-100
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• 1985

A observation of the ovarian development and oogenesis of Pieris rapae Linne has been carried out during metamorphosis using stereo-microscope, light microscope and electron microscope. The results obtained through this experiment are as follows: 1. The ovarian development and vitellogenesis begin at the 3-day old pupa and the 6-day old pupa respectively, and the adult ovary right after their emergence contains a few mature eggs. 2. The species described above are further observed at six different stages in oogenesis, and the results are summarized as follows. 1) Pieris rapae has polytrophic ovarioles. The cell organelles of the nurse cells are transfered to the oocyte through the ring canal at the early oogenesis. 2) At stage 2, the nuclear envelope of oocyte nucleus is less infolding than that of nurse cell nucleus. In the oocyte cytoplasm a large number of ribosomes are observed. 3) At stage 3 and 4, many micropinocytotic vesicles are observed in the oocyte cytoplasm. These vesicles are fused together to form large proteid yolks. 4) At stage 5, the vitelline membrane is laid down in the intercellular space between the follicle cells and oocyte. 5) At stage 6, the chorion is formed by the follicle cells. 6) A micropyle and a number of aeropyle are observed on the surface of a mature egg.

• 한국수정란이식학회지
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• 제33권2호
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• pp.69-73
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• 2018

This study was conducted to examine the influences of two human chorion gonadotrophins (hCGs) being injected into young or aged (45- to 65-week old) outbred (ICR) mice on developmental capacity of oocytes retrieved. In vitro-culture and parthenogenetic activation of oocytes retrieved were employed for the assessment. Superovulation was determined as being induced when more than 25 oocytes were retrieved. No aged mice were superovulated, while in contrast, 67-100% were superovulated in the 6- to 8-week-old (young) mice. In the aged, hCG injection yielded better retrieval (5 vs. 13 to 14.8 oocytes/mouse). Overall, no significant difference between two hCGs was detected but between the young and aged, significant differences in maturational arrest (0% vs. 39% MI arrest and 46% vs. 15% degeneration) and developmental capacity (24% vs. 46% 8-cell embryo development) were detected. In conclusion, hCG injection contributes to increasing oocyte retrieval from aged outbred mice, but the kinds of gonadotrophin influenced the efficiency of hyperstimulation induction in specific ages.

• Molecules and Cells
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• 제42권8호
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• pp.589-596
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• 2019

${\beta}Pix$ is a guanine nucleotide exchange factor for the Rho family small GTPases, Rac1 and Cdc42. It is known to regulate focal adhesion dynamics and cell migration. However, the in vivo role of ${\beta}Pix$ is currently not well understood. Here, we report the production and characterization of ${\beta}Pix$-KO mice. Loss of ${\beta}Pix$ results in embryonic lethality accompanied by abnormal developmental features, such as incomplete neural tube closure, impaired axial rotation, and failure of allantois-chorion fusion. We also generated ${\beta}Pix$-KO mouse embryonic fibroblasts (MEFs) to examine ${\beta}Pix$ function in mouse fibroblasts. ${\beta}Pix$-KO MEFs exhibit decreased Rac1 activity, and defects in cell spreading and platelet-derived growth factor (PDGF)-induced ruffle formation and chemotaxis. The average size of focal adhesions is increased in ${\beta}Pix$-KO MEFs. Interestingly, ${\beta}Pix$-KO MEFs showed increased motility in random migration and rapid wound healing with elevated levels of MLC2 phosphorylation. Taken together, our data demonstrate that ${\beta}Pix$ plays essential roles in early embryonic development, cell spreading, and cell migration in fibroblasts.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2451-2456
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• 2003

In biological cell manipulation, manual thrust or penetration of an injection pipette into an egg is currently performed by a skilled operator, relying only on visual feedback information. Massive load of various micro injection of either genes, fluid or cells in the postgenomic era calls a more reliable and automatic micro injection system that can test hundreds of genes or cell types at a single experiment. We initiated to study cellular force sensing in zebrafish eggs as the first step for the development of a more controllable micro injection system by any inexperienced operator. Zebrafish eggs at different developmental stages were collected and an integrated biomanipulation system was employed to measure cellular force during penetrating the egg envelope, the chorion. First of all, the biomanipulation system integrated with cellular force sensing instrument is implemented to measure the penetration force of cell membranes and characterize mechanical properties of zebrafish embryo cells. Furthermore, implementation of cellular force sensing system and calibration are presented. Finally, the cellular force sensing of penetrating cell membranes at each developmental stages was experimentally performed. The results demonstrated that the biomanipulation system with force sensing capability can measure cellular force at real-time while the injection operation is undergoing. The magnitude of the measured force was in the range of several hundreds of uN. The precise real-time measurement should provide the first step forwards for the development of an automatic and reliable injection system of various materials into biological cells.

• 한국잠사곤충학회지
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• 제38권1호
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• pp.48-52
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• 1996

Nosema bombycis의 경란전염은 집누에의 경우 난내 및 난면의 두가지 경로가 존재하는 것으로 입증되었다. 난내에서 병원체가 존재하는 부위가 난각 조직을 제외한 장액막, 난황, 배자 등이였다. 난내에 침입한 병원체는 난의 발육과 동조적으로 발육 증식하므로써 오랜 시일이 경과하여도 불활화 되지 않는 동시에 감염난의 치사를 줄일 수 있으며, 병원체가 안전하고 확실하게 차대의 유충으로 전달되므로난내경로는 경난전염율이 높은 것으로 밝혀졌다. 난면경로는 감염 모체의 아충에 의한 난 표면의 오염이 주 원인으로서, N. bombycis 감염아는 100%가 아뇨에 병원체가 검출되며, 4.6$\pm$0.24)X106/ml의 포자를 함유하는 것으로 밝혀졌다. 난 표면에 부착된 병원포자는 비휴면란에 도말하였을 때, 10일 정도 경과 후 부화된 유충의 54.5%가 감염되었으나, 월년 보호하거나 침산한 경우 차대잠의 감염은 인정되지 않았다. 따라서, 집누에 월년란의 경우 경란전염에 의한 질병의 만연에는 난내경로가 주요한 것으로 결론지었다.