• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.2
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• pp.79-83
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• 2006

We successfully extirpated all four hemopoietic organ-wing disc complexes of the fifth instar larvae of Bombyx mori, and found that most of the treated silkworms could still develop into the moths. We investigated the changes of the circulating hemocytes and evaluated the effects of extirpation on the hemopoiesis. The results showed that proliferation of circulating hemocytes was sufficient to allow development of the silkworms which complexes were totally extirpated. We also found that hemopoietic organ-wing disc complexes extirpation might cause a certain hemopoietic compensation of the remainder complexes during early spinning. Exogenous hormones such as $20-{\beta}-hydroxyecdysone$ and juvenile hormone analog had a positive effect on hemocytes proliferation.

• Applied Microscopy
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• v.20 no.2
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• pp.46-56
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• 1990

Ultrastructure of the hemopoietic organ in the grasshopper, Euprepocnemis shirakii, was studied using light and electron microscopes. The hemopoietic organs located on the upper surface of the dorsal diaphragm between 1st and 8th segments were consisted of 3 kinds of cells; the reticular cells, stem cells and two types of granulocytes. The reticular cells had numerous cytoplasmic processes and forming a complex network. Characteristically, pinocytotic vesicles and rough endoplasmic reticulum were well developed in this cell. The stem cells give rise to differentiating hemocytes of the different cell lineages. Granulocytes within the hemopoietic organs were originated from the stern cells and differentiated into two types of hemocytes ; granulocyte( I ), granulocyte( II ).

• Korean Journal of Veterinary Research
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• v.45 no.4
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• pp.517-525
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• 2005

This study was performed to evaluate using wild-type (WT) and $C{\times}32$ knockout (KO) mice if lack of cell to cell communication by connexin 32 gap junction enhances the benzene-induced hematotoxicity and hemopoietic tumor development. The WT and $C{\times}32$ KO mice were exposed to 300 ppm of benzene for 6 hours/day, 5 days/week for a total of 26 weeks by inhalation, and then sacrificed to evaluate the toxicities of hemopoietic organs or allowed to live out their life span to evaluate the hemopoietic tumor incidence. The significant increase and decrease of organ weight were respectively noted in spleen and thymus of both WT and $C{\times}32$ KO mice without significant difference between the genotypes. Histopathologically, benzene exposure for 26 weeks induced the morphological changes in hemopoietic organs, characterized by fat cell accumulation in the bone marrow and extramedullary hemopoiesis in the spleen. The fat cell accumulation was, compared with that of WT mice, considerably exacerbated in the $C{\times}32$ KO mice. However, no significant difference was observed in the changes of hematological values and bone marrow cellularity as well as in the onset and incidence of hemopoietic tumors between WT and $C{\times}32$ KO mice. In conclusion, this study indicated little significant role of the cellular communication by $C{\times}32$ gap junction in the action mechanism of benzene hematotoxicity and leukemogenicity.

• Applied Microscopy
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• v.33 no.2
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• pp.131-143
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• 2003

A Differentiating pathway of hemocytes in vitro and in vivo of grasshopper, Euprepocnemis shirakii was described using light and electron microscopes. In the interior of body, the stem cells of the hemopoietic organ differentiated into six types of cells respectively which are prohemoyte, plasmatocyte, granulocyte I, granulocyte II, spherulocyte and oenocytoid. The formation of these hemocytes was derived from the stem cells surrounded by a reticular cell. Hemopoietic tissue cultured in the insect media differentiated different hemocytes, but none of them underwent any mitotic division. Morphological features of the cultured cells in media were essentially the same as those of the hemocytes differentiated from the stem cells in vivo. These results were shown that each stem cell could differentiate into different types of hemocytes. It was confirmed that the stem cells possessed the pluripotent differentiation ability to directly each hemocyte, and that the once formed hemocytes in vivo and in vitro didn t undergo further transformation to other hemocytes. The maintenance of circulating hemocytes in grasshopper had been depended on the widely spreading hemopoietic organ situated in the upper surface of the dorsal alary muscle and located on the first to eighth segments.

• The Korean Journal of Zoology
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• v.37 no.4
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• pp.514-523
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• 1994

꼬리명주나비(서ericinus montela) 조혈기관의 분포 및 미세구조를 광학현미경과 투과전자현미경을 이용하여 관찰하였다. 꼬리명주나비의 조혈기관은 흉부 제 2 · 3체절의 날개발생부위(imaginal wing disc)에 부착되었거나 인접해 있었다 각각의 조혈기관은 비세포성 기저 막으로 둘러싸인 여러 개의 조혈섬으로 구성되어 있었으며, 조혈 섬들은 compact islet(치밀하게 배열된 조혈섬)과 loose islet(느슨하게 배열된 조혈섬)으로 구분되었다. 혈구의 분화는 loose islet 내에서 진행되었으며, 시원세포로부터 원시혈구. 부정형혈구, 과립혈구, 소구혈구가 독자적 경로를 통해 분화되었다.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2001.05a
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• pp.101-101
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• 2001

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.184.2-184
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• 1997

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 2001.04a
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• pp.67.1-67
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• 2001

No Abstract, See Full Text

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.313-323
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• 1995

Ultrastructural characteristics of hemocytic differentiation pathway in Sericinus montetla Grey were observed with transmission electron microscope. Hemocytic differentiation took place in loose islets of hemopoietic organs as indicated by the presence of differentiating hemocytes; prohemocytes, plasmatocytes, granular cells and spherule cells. They are differentiatied from the stem cells through individual cell lineages. However, differentiating aspects of the oenocytoids were not observed. According to Brehelin and Zachary (1986), the premature hemocytes around the hemopoietic organs were classified into five types; prohemocytes, plasmatocytes, granular cells, spherule cells and oenocytoids.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.05a
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• pp.104-104
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• 2002