• The Korean Journal of Ecology
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• v.12 no.1
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• pp.37-49
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• 1989

When the light stimulus was presented continuously, habituations were formed, after 13 and 14 hrs in amoeba and planaria, repectively. As amoeba more habituated, the light-escaping velocity of streaming was decreased with a negative-exponential function. in two-dimensional electrophoretic patterns of proteins of amoeba habituated, a newly synthesized protein (pI 7.0, MW 20 kD) was detected. Therefore, it is conjectured that similarity or commonality may exist between amoeba and planaria habituations to light, and in these behavioral modifications, specific protein(s) may be involved in molecular level.

• Applied Microscopy
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• v.20 no.1
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• pp.1-16
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• 1990

The epidermal tissue of Korean planaria Phagocata vivida(Ijima et Kaburaki) is composed of the simple columnar epithelium. The ventral epidermis of this animals is thinner than the dorsal epidermis and has a furrow in the median line in which dark cell is observed. The clear cells which are electron-lucent are located either side of the dark cells. Those are compactly covered with long cilia. The free surface of the latero-ventral epidermis is tightly contacted with the earth and this epidermal free surface has a great number of short cilia, and a lot of C-type of basophilic granule cell are migrated into the cytoplasm of epithelium from mesenchyme passing through the basement membrane and then this granules are put out of latero-ventral free surface. Dorsal epidermis is thickest among the whole epidermis of these animals and the rhabdite granules are more distributed in dorsal epidermis than in ventral epidermis. According to the cytochemical and ultrastructural research, composed epidermis of this planaria are divided into nine type cells, that is, ciliated columnar epithelium, dark cell, mucous cell, rhabdite-forming cell, sunk round cell, A type, B type, C type and D type of basophilic granule cell.

• KSBB Journal
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• v.29 no.1
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• pp.67-71
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• 2014

Planaria were recently reported to be a simple and sensitive model to investigate the mechanistic aspect of seizure and to screen potential anticonvulsants. Using planarian model, we analyzed the pharmacological effect of ukgansan (UGS), an oriental herbal medicine containing seven medicinal herbs, on the planarian locomotor velocity (pLMV) and glutamate-induced seizure-like activity (pSLA). To test whether D. japonica is suitable for studying anti-seizure agents, we investigated the effect of glutamate on pLMV and pSLA in D. japonica. In the present study we first confirmed that pSLA in D. japonica was induced by L-glutamate. Glutamate significantly produced pSLA in a dose dependent manner, but did not affect pLMV. These glutamate-induced paroxysms were decreased by antiepileptic drug, topiramate. A similar inhibitory effect on glutamate-induced pSLA was observed after the treatment of UGS. The present results suggest that UGS and its active constituents possess useful substance inhibiting seizure in planarian and that D. japonica provides a convenient model to search active herbs containing anti-seizure activity.

• The Korean Journal of Zoology
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• v.28 no.3
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• pp.194-208
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• 1985

The ultrastructure of the integumental epidermis of Korean planaria (Dugesia japonica) is studied by light microscope, scanning electron microscope and transmission electron microscope. The planaria has mono-layered integumental epidermis in which most of cells exhibit irregularly columnar shape. The epidermal cells of the integument are classified into six types on the basis of cytochemical and ultrastructural characteristics. 1) Ciliated epithelial cells: These cells have cilia in their free surfaces. The axonemes of cilia exhibits fundamental 9+2 microtubular pattern. 2) Eosinophilic cells: These cells contain a few large eosinophilic granules. The core of eosinophilic granule is consisted of sparsely dispersed fibrillar structures in relatively electron-lucent ground material. 3) Mucous cells: These cells are filled with irregularly shaped, PAS-positive mucous granules which have an average size of $0.8\\times0.3 \\muM$. 4) Rhabdite-forming cells: These cells possess a few strongly-eosinophilic large rhabdite granules. The rhabdite granules are synthesized either in the rhabdite-forming cells which constitute integumental epidermis or in the corresponding cells which are developed in the parenchyma and later transferred to epidermal cells of integumental epidermis through basement membrane. 5) A-type of basophilic granule cells: These granule cells possess round or irregularly-shaped granules which are strongly stained with Alcian blue. These electron-dense granules have an average size of $1.5\\times1.0 \\muM$. This type of cells is derived from parenchymal tissue. 6) B-type of basophilic granule cells: These basophilic granule cells with PAS-positive granules, are found in the epidermis of lateral body wall. The granules, which are about $0.7\\times0.4 \\muM$ in size, occupying most part of this cell type are originated from the parenchyma.

• BMB Reports
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• v.49 no.5
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• pp.249-254
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• 2016

All living things share some common life processes, such as growth and reproduction, and have the ability to respond to their environment. However, each type of organism has its own specialized way of managing biological events. Genetic sequences determine phenotypic and physiological traits. Based on genetic information, comparative genomics has been used to delineate the differences and similarities between various genomes, and significant progress has been made in understanding regenerative biology by comparing the genomes of a variety of lower animal models of regeneration, such as planaria, zebra fish, and newts. However, the genome of lizards has been relatively ignored until recently, even though lizards have been studied as an excellent amniote model of tissue regeneration. Very recently, whole genome sequences of lizards have been uncovered, and several attempts have been made to find regeneration factors based on genetic information. In this article, recent advances in comparative analysis of the lizard genome are introduced, and their biological implications and putative applications for regenerative medicine and stem cell biology are discussed.

• The Korean Journal of Zoology
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• v.28 no.4
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• pp.211-226
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• 1985

The ultrastructure of the digestive organ of Korean Planaria (Dugesia japonica) is studied by light microscope and transmission electron microscope. 1. Pharynx The epithelium surrounding pharyngeal lumen has a number of microvilli on the free surface. The epithelial cells contain PAS-positive granules which are 0.4 to 0.6 $\\mum$ in size. They also contain hundreds of vesicles and vacuoles. The pharyngeal epithelium of the external surface surrounded by pharyngeal cavity possesses a number of cilia and microvilli on the free surface. A number of muscle bundles are found in the pharyngeal tissue. The parietal epithelium surrounding pharyngeal cavity have microvilli and electron-dense secretory granules. 2. Caeca The cells which constitute the cecal epithelium are divided into four kinds of cells. 1) Phagocytic cell : These cells are characterized by presence of a number of lysosomes. These cells have highly developed mitochondria, polyribosomes and granular endoplasmic reticulum of which cisternae are distended. 2) Granular club cell : These cells contain round granules 5 $\\mum$ in diameter which show strong PAS-positivity and weak eosinophilia. The cells have highly developed granular endoplasmic reticulum. 3) Storage cell : These cells include thousands of glycogen granules in the cytoplasm. These cells also have second kind of round granules which are 1.4 to 3 $\\mum$ in size and exhibit PAS-positive reaction. 4) Immature storage cell : These cells have a large nucleus and contain a small number of granules which have PAS-positive granules and a few lipid droplets. Several chromatoid bodies are found in the cytoplasm around the nucleus.

• Applied Microscopy
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• v.15 no.1
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• pp.31-58
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• 1985

The morphological study on different types of cells of reproductive organ including spermatogenesis in the adult planaria was performed to observe their cytochemical and ultrastructural characteristics. 1. Spermatogenesis The circular luminated material appears immediately inside the nuclear envelope of early spermatid and is found also in the nucleus of sperm, but typical acrosomal structures cannot be observed. Approximately ten of small-sized mitochondria occur around the nucleus in the transitional phase from primary spermatocyte to secondary spermatocyte, but in sperm a long mitochondrion is closely associated with nucleus, parellel to long axis of it. The sperm has a relatively long head connected with two tails via hollow neck. 2. Reproductive organ The penis bulb and the bursa stalk were observed. (1) Penis bulb The cells constituted penis bulb are classified into six types on the basis of ultrastructure of the cells and cytochemistry of the cytoplasmic granules. 1) A-type cells: These cells exhibiting low electron density are mainly occupied by large nucleus. These cells possess two different types of granules: highly electron-dense round granules with an average size of $0.9{\mu}m$, and electron-dense granules exhibit PAS-positive reaction. 2) B-type cells contain PAS-positive granules with the size of about $0.4{\mu}m$. They are rich in free ribosomes and mitochondria. 3) C-type cells are found to be dark cells due to high electron-density. These cells are largely occupied by large nucleus. 4) D-type cells: These cells are seen as light cells which have poorly developed cell organelles. 5) E-type tells: These cells contain a large number of glycogen granules which occupy most of cell. 6) F-type cells: These arc parietal epidermal cells surrounding the genital antrum. These cells are characterized by their finger-like shapes and the presence of a number of electron-dense, irregularly-shaped structures inside cells. The relatively large electron-lucent granules can be also found. The F-type cells possess numerous microvilli on their free surfaces. (2) Bursa stalk The cells constituted bursa stalk are classified into 3 types on the basis of cell shapes and presences of electron-dense or electron-lucent granules. 7) G-type cells with a long cytoplasmic process. They have large nuclei and poorly developed cell organelles. 8) H-type cells: These cells are characterized by the presence of a long cytoplasmic process and relatively highly electron-dense cytoplasmic profile. They have poorly developed cell organelles. 9) I-type cells contain large electron-lucent granules which exhibit negative reactions with three kinds of cytochemical staining methods used in this experiment. The fine electron-dense structures can be found inside these granules.

• The Korean Journal of Zoology
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• v.24 no.3
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• pp.151-161
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• 1981

The field studies on the seasonal population prevalences of the vector mosquito larvae and other aquatic invertebrates were weekly carried out in the rice fields located in front of a village of Kwangtan-samri, Byeogje-myeon, Goyang-gun, Gyeonggido throughout mosquito breeding season (June-September) in 1980, and the results are as follows. The population of C. tritaeniorhynchus larvae increased soon after heavy rainfall, and decreased to some extent during the period of the insecticide application. The seasonal prevalence of A. sinensis was rather stable, not being affected by insecticide pressure at all. The population densities of other aquatic invertebrates in rice fields were seriously suppressed by the pesticide application, and their recovery was not as same as the previous level or not at all: (1) The populations of Odonata and Ephemeroptera nymphs were drastically decreased by the first application of insecticides and never recovered through out season. (2) Coleoptera seemed very susceptible to the insecticide application, as densities were markedly decreased whenever the insecticides were applied. (3) The high density of Hemiptera shown in early June were decreased sharply after the first application of pesticides, and thereasfter, some degree of recovery was shown, but suppressed by successive each application of pesticides. (4) A native species of planaria was exceptionally not influenced by the insecticide pressure, and two peaks of the density were appeared during the heavy rainfall.

• Applied Microscopy
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• v.29 no.1
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• pp.57-66
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• 1999

The nervous tissue in the cerebral ganglion of Korean planaria was observed using electron microscope. The obtained results are as follows: A cerebral ganglion is composed of the nerve cells, neurosecretory cells, neuroglial cells and neuropils. The nerve cells are round or ovoidal-shaped cells (diameter, $5{\mu}m$), which has a large ellipsoidal nucleus containing the evenly developed heterochromatin. Their cytoplasms were found to be relatively simple, because of their undeveloped cell organelles. The neurosecretory cells are long and ellipsoid or spindle-shaped cells, where there were found a large ellipsoidal nucleus and cytoplasm filled with secretory granules (diameter, 60 nm). The neuroglial cells were seldom observed. They are spindle-shaped cells (size, $6\times0.8{\mu}m$), which were observed mainly among the nerve fibers. The neuropils are formed by the nerve fibers and nerve endings which are filled with mitochondria, neurotubules and secretory granules of four kinds (high electron dense granules of sizes 75 nm, 50 nm and 37 nm, and electron lucent granule of size 30 nm etc.). These granular vesicles are divided into single vesicle type and compound vesicle type in the nerve terminals, and neuronal synapses were observed to be the axo-dendritic and dendro-dendritic synapse type.

• Journal of Photoscience
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• v.9 no.2
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• pp.287-289
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• 2002

Planarians show negative phototaxis and have extensive regenerative ability, including the ability to regenerate the brain. Recently the process of regeneration of the planarian brain has been divided into three steps based on the expression of neural markers. In this study, we have analyzed the process of recovery of the light response during head regeneration. Although morphological observations indicated that regeneration of the eyes and optic nerves appeared to be completed by the fourth day, the recovery of the evasion behavior against light was not recovered within 4 days after amputation. Functional recovery of the evasion behavior could be detected starting 5 days after amputation and then gradually recovered. We previously identified genes which are specifically expressed in the brain after the recovery of morphological structures. This characteristic suggested that these genes may be involved in functional recovery of the brain. To investigate the function of these genes, we performed gene knockout analysis using the RNA interference method. The results clearly indicated that these genes are involved in the functional recovery of the visual system.