• ALGAE
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• 제31권4호
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• pp.379-390
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• 2016

When a multinucleate cell of Bryopsis plumosa was collapsed by a physical wounding, the extruded protoplasm aggregated into numerous protoplasmic masses in sea water. A polysaccharide envelope which initially covered the protoplasmic mass was peeled off when a cell membrane developed on the surface of protoplast in 12 h after the wounding. Transmission electron microscopy showed that the protoplasmic mass began to form a continuous cell membrane at 6 h after the wounding. The newly generated cell membrane repeated collapse and rebuilding process several times until cell wall developed on the surface. Golgi bodies with numerous vesicles accumulated at the peripheral region of the rebuilding cell at 24 h after the wounding when the cell wall began to develop. Several layers of cell wall with distinctive electron density developed within 48-72 h after the wounding. Proteome profile changed dramatically at each stage of cell rebuilding process. Most proteins, which were up-regulated during the early stage of cell rebuilding disappeared or reduced significantly by 24-48 h. About 70-80% of protein spots detected at 48 h after the wounding were newly appeared ones. The expression pattern of 29 representative proteins was analyzed and the internal amino acid sequences were obtained using mass spectrometry. Our results showed that a massive shift of gene expression occurs during the cell-rebuilding process of B. plumosa.

• Applied Microscopy
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• 제51권
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• pp.3.1-3.6
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• 2021

We examined the morphology of fertilized egg and ultrastructures of fertilized egg envelopes of dwarf rainbowfish (Melanotaenia praecox) belong to Melanotaeniidae using light and electron microscopes. The fertilized eggs were spherical with adhesive filament, transparent, demersal, and had a narrow perivitelline space and small oil droplets. The size of fertilized egg was 1.02 ± 0.18 mm (n = 30), and there were two kinds of adhesive filament on the fertilized eggs. The long and thick (diameter 12.22 ± 0.52 ㎛, n = 20) adhesive filaments were only at the area of animal pole, and short and thin (diameter 1.99 ± 0.23 ㎛, n = 20) adhesive filaments were around the long filaments. A micropyle was conical shaped with adhesive filament and located near the animal pole of egg. The outer surface of fertilized egg was rough side. Also, the total thickness of the fertilized egg envelope was about 7.46 ± 0.41 ㎛ (n = 20), the fertilized egg envelope consisted of two layers, an inner lamellae layer and an outer layer with high electron-density. And the inner layer was 8 layers. Collectively, these morphological characteristics and adhesive property of fertilized egg with adhesive filaments, and ultrastructures of micropyle, outer surface, and section of fertilized egg envelope are showed species specificity.

• Applied Microscopy
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• 제26권4호
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• pp.401-410
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• 1996

The microwave fixator has recently been introduced in morphological research. The present study was carried out to investigate the ultrastructural effects of microwave fixation of rat brain. kidney, liver and skeletal muscle tissues. The results are as follows: In the case of microwave fixed cerebrum. the cytoplasmic processes of neurons and the various membranous organelles such as nuclear envelope, mitochondria, rough endoplasmic reticulum and Golgi apparatus were well preserved, The myelin sheath wrapping neuronal axon was prominent. Microwave fixed hepatocytes showed the microvilli on the free surface of bile canaliculus, the evident nucleolar components, and typical organelles. In nephron, ultrastructures of glomerulus and Bowman's capsule were preserved, and also tubular wall were structurally observed. Among the skeletal muscle cells, plentiful collagen fibers were appeared, myofibrils and mitochondria were typically observed. In conclusion, the microwave fixation procedures result in an good preservation of the tissues and would be time- and reagent-saving.

• Applied Microscopy
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• 제20권2호
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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 ).

• Journal of the Korean Wood Science and Technology
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• 제36권2호
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• pp.9-20
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• 2008

Anatomical comparison of 3 North American species with commercial name of redcedar was executed to provide taxonomic information for prevention of confusion and establishment of sound business transaction in the wood market. Eastern redcedar (Juniperus virginiana) and southern redcedar (Juniperus silicicola) could not be separated on the basis of microstructure and ultrastructure of wood. Western redcedar (Thuja plicata), however, appeared to be obviously separated from eastern and southern redcedar in a number of microscopic and ultramicroscopic features. Useful features for separating these two groups were intercellular spaces in transverse surface, latewood width, radial intertracheid pitting, warty layer and pits with torus extensions in tracheids, ray composition, nodular end walls in ray parenchyma cells, and cross-field pitting.

• 한국수산과학회지
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• 제36권6호
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• pp.641-645
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• 2003

Spermatogenesis, ultrastructure, and sperm morphology of the Pacific oyster (Crassostrea gigas) were investigated with TEM and SEM. C. gigas sperm were primitive consisting of a head midpiece and tail. Sperm size (head and midpiece) was about 1.78 ${\mu}m$. Sperm morphology was similar to a sharp of a small water jar with a rough surface. Sperm had both anterior nuclear fossa (anf) and posterior nuclear fossa (pnf). Acrosome forms had a hat-like shape. The axial rod was projected in front of the acrosome. C. gigas sperm had four large mitochondria in the midpiece.

• Applied Microscopy
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• 제28권2호
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• pp.159-170
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• 1998

The glandular secretory system of the capitate gandular trichomes in leaf of Thymus quinquecostatus Celakovsky was examined by transmission electron microscope. The glandular trichome was consisted of three cell layers; an basal cell layer, a stalk cell with single-celled intermediate layer and a discoid secretory layer with thickened cuticle. The secretory cell was dense, rich in mitochondria, rER, plastds, Golgi complex and had many vesicular structure. Typical plastids with reticulate body and plastoglobule were present in glandular trichome. The tytoplasm of secretory cell was filled with osmiophilic secretory materials. The secretory vesicles, originated from Golgi complex, appeared as membrane bounded vesicles and secreted to the outer wall surface. The presences of well developed rER, mitochondria, Golgi complex, and membrane-bounded vesicles fused with plasmalemma in the secreting cells indicate that the granulocrine mechanism of secretion was occurring in T. quinquecostatus. Subcuticular cavity was developed between the cuticular layer and the secretory cell wall, and it formed above the secretory cell upon separation of cuticle-wall.

• Parasites, Hosts and Diseases
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• 제40권2호
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• pp.67-73
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• 2002

The present study was performed to observe tegumental ultrastructure of Echinoparyphium recurvatum according to developmental stages. Worms (1, 3, 5 and 15-day old) were recovered from chicks experimentally infected with metacercariae from radix auricularia coreana. One-day old worms were elongated and ventrally concave, and covered with peg-like tegumental spines except the adjacent areas of the head crown and excretory pore. Type I sensory papillae were distributed on the lip of the oral sucker, and grouped ciliated papillae were around the oral sucker. Peg-like tegumental spines were densely distributed on the anterior surface of the ventral sucker level. The ventral sucker had an aspinous tegument and no sensory papillae. Tegumental spines on the posterior surface of the ventral sucker level were sparsely distributed and disappeared posteriorly. In 3 and 5-day old worms, the tegument around the oral sucker was aspinose and wrinkled concentrically. The ventral sucker had a wrinkled tegument and many bulbous papillae. Type I sensory papillae were distributed between the bulbous papillae. Tegumental spines were spade-shaped with a terminal tip. A total of 45 collar spines including 4 end group ones on both ventral corners was alternately arranged in 2 rows. The 15-day old worms were very stout and their tegumental spines were tongue-shaped without a terminal tip, From the above results, it is confirmed that the surface ultrastructure of E. recurvatum was generally similar to that of other echinostomatid flukes. However, some features, i.e., morphological change of tegumental spines and appearence of sensory papillae on the ventral sucker according to development, and number, shape and arrangement of collar spines, were characteristic, which may be of taxonomic and bioecological significance.

• Applied Microscopy
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• 제39권4호
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• pp.319-324
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• 2009

농어 아가미는 새파, 새궁, 새엽 및 새판으로 구성되어 있었다. 위쪽 새파수는 7~10개이며, 아래쪽 새파수는 13~18개로 조사되었다. 농어 아가미의 주요부위인 새엽과 새판(이차새엽)을 광학현미경과 투과전자현미경에서 관찰한 결과는 다음과 같다. 농어 아가미는 새궁(gill arch) 외연의 앞 뒤 2열로 된 긴 점막성의 빗살과 같은 모양으로 줄지어 있는 많은 수의 새엽(gill filament)을 가지고 있으며, 각 새엽은 전후 두개의 새판(gill lamellae)이 근접하여 두 열로 배열되어 있었다. 농어의 새판은 pavement cell, 기둥세포(pillar cell), 혈구세포, 점액세포(mucose cell) 및 염류세포(chloride cell) 등으로 구분되었다. 새판의 표면은 단층으로 큰 핵을 가진 pavement 세포로 구성되며, 상피표면의 glycocalyx로 덮혀진 미세융기를 가진다. 그리고 새판은 기둥세포와 혈구세포와 일정한 간격을 두고 분포하고 있었다. 점액세포는 새판에 드문드문 나타났지만 새엽에 많이 분포하고 있으며, 염류세포는 미토콘드리아와 tubular system이 잘 발달되어 있었다.

• Applied Microscopy
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• 제30권4호
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• pp.321-326
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• 2000

경골어류, 잉어과에 속하는 피라미 수정란을 실험재료로 사용하여 난문의 미세구조, 난막의 표면 및 단면구조를 밝힘으로써 계통분류학적 기초자료를 제시하고자 주사전자현미경과 투과전자현미경을 이용하여 관찰하였다. 피라미의 수정란은 부착성란으로 동물극 쪽에 수정을 위한 정자의 통로로 생각되는 한 개의 난문이 관찰되었고 이 난문은 5개의 돌출물에 의해 둘러싸여 있었다. 난막의 표면은 부속구조물들은 관찰되지 않았고, 수많은 pore canal들이 분포하고 있었으며 난막은 모두 3층으로 부착성인 전자밀도가 낮은 외층, 전자밀도가 높은 중층 및 9층의 층상구조를 이룬 내층으로 구성되어 있었다. 이상과 같은 피라미 수정란 난막의 미세구조적 특징은 피라미의 수정란이 가지는 독특한 형태학적 형질로서 종을 분류하는데 사용될 수 있을 것으로 사료된다.