• Animal cells and systems
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• v.3 no.4
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• pp.369-374
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• 1999

The life history and development of Tetrastichus sp. parasitizing fallwebworm pupa in Korea were studied. The mean lifetime fecundity was 94.7 with a maximum of 125, and the portion of female progeny averaged 90.3%. A male and a female lived for an average of 19.8${\pm}$4.5 and 21.7${\pm}$4.2 days, respectively. The duration of development for each stage was as follows: egg, 2 d; the 1st instar larva, 2${\pm}$1 d; the 2nd instar larva, 2${\pm}$1 d: the 3rd instar larva, 3${\pm}$1 d; the 4th instar larva, 6${\pm}$2 d; and pupa, 8${\pm}$2 d. Total developmental duration from hatching of the larva to adult emergence required 21.1${\pm}$3.7 d, and females took 1-2 days more than males in the incubator (28$^{\circ}C$, 70% RH, and 16:8 LD).

• Animal cells and systems
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• v.6 no.1
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• pp.65-68
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• 2002

Female genital morphology of Cryptocercus Kyebangensis is described, focusing on the structural features of ovipositors at each developmental stage. Ovipositor valves were the first genital structures to appear in female nymphs. The caudal margin of the 9th sternum was nearly straight in the 1st instars of both sexes, with a slight median notch, but was deeply concave in the female nymphs of the End instar. The 1st valve of ovipositor budded off from membranous fold between the 8th 8nd 9th sternum and a pair of the 2nd valve came from the 9th sternum. Separation of styli occurred in the female nymphs of the 8th or 9th instar. Some parts of the female genitalia were sclerotized after the final molt. Spermathecae were the fork type and leaned a little to the right in the middle line of the genital chamber from ventro-posterior view. The trace sealed with sclerite materials existed on the spermathecal opening. The genital segments (segments Ⅷ, IX, and X) were concealed completely by the 7th tergum and sternum posteriorly expanded. Terminal lobes which exist in the Blattidae were not observed in C. Kyebangensis. Instead, the apicolateral emargination existed on the terminal abdominal segment of C. Kyebangensis females.

• International Journal of Oral Biology
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• v.34 no.3
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• pp.143-150
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• 2009

Amino acid transporters play important roles in supplying nutrients to cells. In our current study, we investigated the expression of LAT1 and measured the amino acid uptake in ameloblast cultures to further elucidate the roles of this transporter during the differentiation of these cells. RT-PCR, observations of cell morphology, Alizaline red-S staining, and uptake analyses were performed following the experimental induction of differentiation in the cultures. LAT1 mRNA was detectable and found to gradually increase over time whereas LAT2 mRNA was not evident in the ameloblast cultures. Transcripts of 4F2hc, a cofactor of LAT1 and LAT2, were also found to be expressed in ameloblast cultures and increase with time. Amelogenin mRNA was expressed in the early stage ameloblast cultures. L-leucine uptake was observed to increase over 14 days of growth in culture. Our data suggest that LAT1 has a key role in the differentiation of ameloblasts and in providing these cells with neutral amino acids, including several essential amino acids.

• Development and Reproduction
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• v.23 no.4
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• pp.345-353
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• 2019

Higher thermal exposure can influence the blood cell morphology and count. Hence, based on the previous results (Rahman et al., 2019), the present study evaluated the morphometric indices of erythrocytes and their nucleus under different water temperatures (25℃, 28℃, 31℃, and 34℃) to investigate their use as an indicator of thermal stress in red spotted grouper, Epinephelus akaara. 180 healthy specimens of E. akaara were exposed to four temperature conditions (25℃ as control, 28℃, 31℃, and 34℃) for 42 days, following 2 weeks of acclimation at 25℃. Erythrocyte major axis (EL), erythrocyte minor axis (EW), nucleus major axis (NL), and nucleus minor axis (NW) were examined from the blood smears on each sampling day (i.e., 2, 7, and 42 days of thermal exposure). EL and NL were significantly decreased, whereas EW and NW were increased at higher water temperature (31℃ and 34℃). The major-minor axis proportions of erythrocytes and their nucleus (EL/EW; NL/NW) were decreased with increasing water temperature (31℃ and 34℃). The strong relationships were observed among the morphometric indices of erythrocytes and their nucleus, especially in EL vs. NL and EW vs. NW. This study reveals that elevated water temperature (31℃ and 34℃) can influence the major and minor axis morphometry of erythrocytes and their nucleus in red spotted grouper. These indices may be used as stress indicators to monitor the health status of E. akaara and probably for other fish species.

• Development and Reproduction
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• v.18 no.4
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• pp.241-249
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• 2014

Hyphessobrycon eques is a famous fish for ornamental fish market and aquarium. They are inhabit in regions of Amazon and Paraguay River basin. Serpae fishs were investigated 2-3 males are chased to female, and then males attempted to simulate the females abdomen. After fertilization, eggs were kept in incubators at $28^{\circ}C$. The fertilized eggs had adhesive and demesal characteristics and had a mean diameter of $0.92{\pm}0.01mm$. Larvae hatched at 16 hrs post fertilization. The hatched larvae averaged $2.90{\pm}0.16mm$ in total length ($L_T$). Complete yolk sac resorption and mouth opening occurred on the third day post hatching. At 45 days post hatching, the larvae were $12.5{\pm}1.60mm$ $L_T$ and had reached the juvenile stage.

• The Korean Journal of Zoology
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• v.20 no.2
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• pp.109-122
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• 1977

Ultraviolet irradiation of the vegetal hemisphere of the fertilized frog egg prior to first cleavage resulted in alterations in neural morphogenesis. The sensitivity to UV irradiation dropped drastically at the point of 2/3 time lapse between fertilization and the appearance of the first cleavage furrow. Scannining electron micrographs revealed a decrease in size of the cells on the surface of the irradiated embryos. However, ectoderm exchange frafts indicated that the ectoderm of the irradiated embryo retains its capaciiy to form a completely normal neural morphology and epidermal surface. These facts were interpreted in terms of a decrease in the capacity for invagination during gastrulation, and subsequent primary embryonic induction.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.6
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• pp.467-477
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• 2001

We examined astrocyte regional heterogeneity in their morphological changes in response to various stimuli. Astrocytes were cultured from six different neonatal rat brain regions including cerebral cortex, hippocampus, cerebellum, mid brain, brain stem and hypothalamus. Astrocyte stellation was induced by serum deprivation and the maximum stellation in different regional astrocytes was achieved after 2 h. After 24 h, in all astrocyte cultures, the level of stellation returned to their original level. Cerebellar or hypothalamic astrocytes were the most or the least sensitive, respectively, to serum deprivation. The order of maximum sensitivity to serum deprivation among different regional astrocytes was: cerebellum＞mid $brain{\ge}hippocampus,\;brain\;stem{\ge}cerebral$ cortex＞hypothalamus. Isoproterenol-induced astrocyte stellation was also examined in different regional astrocytes, and similar order of maximum sensitivity as in serum deprivation was observed. Next a possible developmental effect on astrocyte morphological changes was examined in cerebral cortex and cerebellum astrocytes cultured from postnatal day 1 (P1), P4 and P7 rat brains. A much higher sensitivity of cerebellum astrocytes to serum deprivation as well as isoproterenol treatment was consistently observed in P1, P4 and P7-derived astrocytes compared to cerebral cortex astrocytes. The present study demonstrates different regional astrocytes maintain different levels of morphological plasticity in vitro.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.67-67
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• 1993

Mucosal surface of the trachea and larynx is protected by several complex defense mechanism, namely mucociliary clearance, immunoglobulin, antibacterial secretory enzyme, which have also been demonstrated in the middle ear mucosa and eustachian tube. The morphologgy of secretory glands and cells of the trachea and larynx is well-known, but knowledge concerning their development related to secretory activity is still sketchy. The secretory element of the murine trachea and larynx, aging from gestational day 16 to postnatal day 21, was studied using hematoxylin & eosin and alcian blue/periodic acid-Schiff staining including lysozyme immunohistochemistry to investigate the development of secretory element of the murine trachea and larynx and to provide with basis of the future study for developmental morphology of the trachea and larynx. The results of this study suggest that the secretory activity starts to be established immediately after birth with the aeration of the lung.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.335-341
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• 1997

The aims of this study are to establish a stable isolation method of blastomeres from bovine early embryos and examine their developmental potential in vitro Early embryos were produced by maturation and fertilizaion in vitro of bovine follicular oocytes. Blastomeres were isolated from 2~8-cell embryos in $Ca^2$+-, $Mg^2$+-free PBS+EDTA after removing the zonae pellucidae Isolated blastomeres were cultured in CZB containing BOEC for upto 240 hpi. Cleavage rates of them were 18.5%(10 /54) in 1 /2 blastomeres, 33.3%(16/48) in 1/4 blastomeres and 34.2%(14 /41) in 1/8 blastomeres, respectively. The rates of blastocystic vesicle formed were 8.7%(4 /46) in 1/2 blastomeres, 26.6% (17/64) in 1/4 blastomeres and 10.3%(8 /78) in 1/8 blastomeres, respectively. Blastomeres developed into various types of blastocystic vesicles and trophoblastic vesicles as evidenced by the Hoechst 33258 staining and morphology. This results suggest that the isolation method used and subsequent culture of isolated blastomeres from bovine early embryos should be useful to obtain extra embryonic cells for various analyses such as PCR and putative ES cell culture.

• Development and Reproduction
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• v.13 no.1
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• pp.13-23
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• 2009

Recent advances in cell biological and genetic researches have revealed that mitochondrial morphology is highly dynamic and regulated by multiple molecular factors including dynamin-related proteins (DRPs). Considering that the mitochondria play critical roles in the cellular metabolism via ATP synthesis, calcium homeostasis in cooperation with endoplasmic reticulum, and apoptosis, the failure of mitochondrial dynamics is infrequently related to the failure in the normal growth and cellular integrity. In this respect, alteration of mitochondrial dynamics may greatly affect the development of nervous system. In this short review, we discussed molecules involved in the control of mitochondrial dynamics, and provide some perspectives on their significance in the neuronal development.