• Animal cells and systems
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• 제7권3호
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• pp.221-225
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• 2003

The tadpole larva of the ascidian Halocynthia roretzi has two sensory pigment cells in its brain vesicle. To elucidate the temporal requirement for FGF signaling in formation of the pigment cells, embryos were treated with an FGF receptor 1 inhibitor, SU5402, or an MEK inhibitor, U0126 during various embryonic stages. In the present study, it is shown that the embryos treated with SU5402 from the 16-cell stage to the early gastrula stage do not form pigment cells, whereas those treated after the early gastrula stage form pigment cells. In pigment cell formation, embryos suddenly exhibited the sensitivity to SU5402 only for 1 h at the neural plate stage(-4 h after the beginning of gastrulation). When U0126 treatment was carried out at various stages between the 8-cell and late neurula stages, the embryos scarcely formed pigment cells. Pigment cell formation occurred when the embryos were placed in U0126 at early tail bud stage. These results indicate that FGF signaling is involved in pigment cell formation at two separate processes during ascidian embryogenesis, whereas more prolonged period is required for MEK signaling.

• 한국동물학회지
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• 제30권3호
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• pp.292-300
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• 1987

The ultrastructure of the tentacular pigment cells and the origin of the pigment granules in the Chinese mystery snail, Cipangopaludina chinensis malleata Reeve, are studied with electron microscope. Tentacular pigment cells of the Enail are the melanophores which contain electron dense melanosomes(melanin pigment granules) . Melanophores are distributed among the connective tissues but otter kind of dermal chromatephores are not observed. The epidermal melanin units are observed in the epithelial tissues of the tentacles. Among the several kinds of epithelial cells, only the epithelial supporting cells contain these pigment granules. Synthesis of the pigment materials is from the rough ER and pigment granules are finally being packaged and released by the Golgi complexes but limiting membrane of these granules are presumed to be originated from the smooth ER.

• 환경생물
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• 제20권3호
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• pp.232-236
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• 2002

The morphological patterns and the cytopathogenicity time of the Vero cells induced by free $Cd^{2+}$ and pigment-bound $Cd^{2+}$ were observed by inverted microscope in order to investigate the difference of cadmium toxicity. The Vero cells induced by Hee $Cd^{2+}$ of 0.1 mM were shown to have a fatal toxic effect and the cytopathogenicity could be seen early after 6$\pm$2 hours of incubation. Partially affected cells induced by pigment-bound $Cd^{2+}$ of 0.1 mM were shown and the cytopathogenicity could be seen after 20 hours of incubation. The Vero cells grown with free 0.001 mM $Cd^{2+}$ were also affected and the cytopathogenicity could be seen after 17 hours of incubation, whereas the Vero cells grown with 0.001 mM pigment- bound $Cd^{2+}$ were unaffected. The sensitivity of Escherichia coli DH5$\alpha$ bacterial cells was also examined after a short treatment with free $Cd^{2+}$ or pigment-bound $Cd^{2+}$. About 5% of cells survived after 0.01 mM of free $Cd^{2+}$ treatment, while about 68% of cells survived after 0.01 mM of pigment- bound $Cd^{2+}$.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권1호
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• pp.19-22
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• 2003

The semicontinuous production of red pigment by immobilized cells of Bacillus sp. B H-99 was investigated in comparison with free cells. The red pigment produced highest productivity under the conditions of aeration of 0.2 mL/min and 2 mm diameter of gel beads by using 3.0% sodium alginate. Semicontinuous production by immobilized cells showed the highest productivity with replacement of fresh production medium in every 72 h for fourth fermentation cycle following the conditions of red pigment productivity.

• Preventive Nutrition and Food Science
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• 제16권3호
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• pp.230-235
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• 2011

Roasted and retorted (RR) chestnuts develop green pigment spots on their surface during storage. The purpose of this study was to evaluate the cytotoxicity of the green pigment using RAW 264.7, MOLT-4, KATOIII and HT-29 cells. The pigment scraped from RR chestnuts (GP), whole RR chestnuts with green pigment spots (GC), whole RR chestnuts without green pigment (WC) and roasted and frozen stored chestnuts (FC) were extracted in 10% DMSO. MOLT-4 cells were less resistant to the cytotoxicity of the chestnut extracts than the RAW 264.7 cells. The GP extracts did not show different responses against $H_2O_2$-induced oxidative stress and LPS-induced NO production compared to the other extracts. The chestnut extracts did not have proliferative activity on either of the KATOIII or HT-29 cells (p>0.05). Our results from the comparison of the green pigment produced on the surface of the RR chestnuts to chestnuts that do not develop the green pigment suggest that the pigment may not be harmful in terms of either cytotoxicity towards immune cells or proliferation of gastrointestinal cancer cells.

• BMB Reports
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• 제48권4호
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• pp.193-199
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• 2015

Degenerative retinal diseases affect millions of people worldwide, which can lead to the loss of vision. However, therapeutic approaches that can reverse this process are limited. Recent efforts have allowed the possibility of the stem cell-based regeneration of retinal cells and repair of injured retinal tissues. Although the direct differentiation of pluripotent stem cells into terminally differentiated photoreceptor cells comprises one approach, a series of studies revealed the intrinsic regenerative potential of the retina using endogenous retinal stem cells. Muller glial cells, ciliary pigment epithelial cells, and retinal pigment epithelial cells are candidates for such retinal stem cells that can differentiate into multiple types of retinal cells and be integrated into injured or developing retina. In this review, we explore our current understanding of the cellular identity of these candidate retinal stem cells and their therapeutic potential for cell therapy against degenerative retinal diseases. [BMB Reports 2015; 48(4): 193-199]

• Applied Microscopy
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• 제17권1호
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• pp.65-75
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• 1987

The ultrastructure of the cutaneous chromatophores and the origin of pigment granules in the goldfish, Carassius auratus L., are studied with electron microscope. Leucophores contain amorphous pigment granules, leucosomes and melanosomes contain oval shaped electron dense melanin pigment granules. These pigment granules are synthesized from the Golgi complexes of each chromatophores and released into the cytoplasm. Among the dermal chromatophores, another kind of dermal cells, named rER rich cells, are also observed. And pinocytotic vesicles are being formed only the inner surface of the chromatophores adhering to the rER rich cells. From these observations, such hypothesis are being possible that pigment materials are synthesized and transfered from the rER rich cells to dermal chromatophores by the pinocytosis. And next remodelizing mechanisms are carried out by the Golgi complexes of each chromatophores.

• 한국수산과학회지
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• 제39권2호
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• pp.94-99
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• 2006

The tadpole larvae of most ascidians have two sensory pigment cells in their brain vesicle. The anterior otolith pigment cell is sensitive to gravity, whereas the posterior ocellus pigment cell responds to light. Besides these two sensory cells, the larvae also possess another type of sensory receptor cell: hydrostatic pressure receptor (Hpr) cells. The Hpr cells have been presumed to sense hydrostatic water pressure, although no functional analysis has been performed. In larvae of the ascidian Halocynthia reretzi, the development of the Hpr cells and their structure in the brain vesicle are poorly understood. To investigate the morphology and formation of the Hpr cells, we established a monoclonal antibody, Hpr-1, that specifically recognizes Hpr cells. The Hpr-1 antigens became detectable in the brain vesicle at the late tailbud stage. Each Hpr cell projected a small globular body, connected by a short stalk, into the lumen of the brain vesicle. The brain vesicle showed remarkable left-right asymmetry. Pigment cells were located on the right side in the lumen of the brain vesicle, whereas Hpr cells were present in the left side. After metamorphosis, the Hpr cells were observed near the rudimental siphons of the juvenile.

• Applied Microscopy
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• 제27권4호
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• pp.357-372
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• 1997

To study the age-related morphological differences of the retinal pigment cells and Bruch's membrane of mouse, retinae of one week-old, five weeks-old, eight weeks-old, six months-old, twelve months-old, eighteen months-old, twenty-four months-old and thirty months-old ICR mice were dissected out under anesthesia. Pieces of the tissue taken from the posterior region of the retina were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde (0.1 M Millonig's phosphate buffer, pH 7.3), and 1% osmium tetroxide (0.1 M Millonig's phosphate buffer, pH 7.3), and embedded in araldite mixture. The ultrathin sections were stained with uranyl acetate and lead citrate, and were observed under a JEM 100 CX-II electron microscope. Observed results were as follows: 1. Retinae of one week old mouse exhibit that some parts of the pigment cell provided with basal foldings, whereas other parts of the one contain without basal foldings. After (ive weeks-old, all retinal pigment cells have the basal infoldings. 2. In the one week-old, stage 1 and stage 2 melanosomes were observed in the retinal pigments cells, but after five weeks-old, most of the retinal pigment cells contain some matured stage melanosomes (stage III and stage IV). 3. The phagosomes in the retinal pigment cells were increased during aging. 4. After eighteen months-old, electron dense materials are observed within the basal infoldings. 5. After eighteen months-old, the thickness of the Bruch's membrane is prominently increased. The thickness of the basal laminae of the pigment cell and the choriocapillary endothelium is more prominently increased as compared with that of the other components of the Bruch's membrane. 6. The thickness of the basal lamina of the pigment cell is more prominently increased as compared with that of the choriocapillary endothelium on aging. From the above results, it was suggested that the pigment cell and Bruch's membrane matures structurally In five weeks, and the function of the pigment cell is prominently suppressed around eighteen months-old, and thereafter the functional suppression is continued on aging.

• 한국응용곤충학회지
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• 제34권3호
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• pp.266-277
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• 1995

벼멸구는 촉각 기부의 등쪽으로 알모양의 24ㅐ의 겹눈을 가지고 있다. 벼멸구의 겹눈은 각각의 단안이 분리되어 있고, 각각의 낱눈이 단지 그들의 각막렌즈를 통해서만이 빛을 받는 연립상 겹눈이다. 각각의 낱눈은 큐티클성 각막렌즈와 그 안쪽에 수정체가 자리잡고 있다. 망막세포는 수정체 바로 아래쪽에 자리하며, 이들은 중심축쪽으로 감간소체들이 밀집결합되어 감간체를 형성한다. 감간체는 수정체 말단부분에서 시작되어 기저막에 까지 다달으며, 그 길이는 약 110~120${\mu}m$ 정도이다. 수정체는 4개로 구성된 한쌍의 1차색소세포에 의하여 둘러 쌓여 있으며 이것은 또한 부속색소세포에 의하여 둘러 쌓여 있다. 수정체의 기저부위는 망막세포에 의하여 일부가 둘러 쌓여 있고 망막세포의 내벽에서 발생한 감간소체들로 구성된 감간체와 닿아있다. 낱눈의 상층부분은 7개의 망막세포로 구성되어 있으나 3/4부분에서 8번째의 망막세포가 자리잡고 있다. 중앙부위에 위치하고 있는 감간체는 미세용 모들로 구성된 감간소체들로 구성되어 있는데, 이들 미세융모의 단면도는 6각형의 모양을 가지고 있다. 색소세포는 수정체를 감싸고 있는 1차색소세포, 기저막까지 닿아 있는 부속색소세포, 기저막 부위의 기저막색소세포 등 3가지의 색소세포들이 있다.