• The Korean Journal of Ecology
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• 제23권4호
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• pp.323-329
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• 2000

The allelopathic effects of volatile substances from Chamaecyparis obtusa (S. et Z.) Endl. were examined on the germination and seedling growth of some plant species, and on the population growth of some microorganisms. The germination and seedling growth of the receptor plants were suppressed more severely by leaf and fruit essential oils than by those of other parts. Colonial growth of fungi was severely inhibited by essential oils extracted from leaves and fruits. The development of root hairs of the receptor plants was also severely inhibited by the essential oils. The cortical cells at the root tips of Lactuca sativa L. treated with essential oils showed contraction of the cytoplasm, resulting in plasma membranes becoming detached from the cell walls and the cells metamorphosing irregularly. Accumulation of lipid granules inside the contracted cytoplasm and degeneration of mitochondrial cristae were also observed.

• Journal of Species Research
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• 제11권4호
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• pp.287-295
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• 2022

Three oxytrichid ciliates, Oxytricha lithofera Foissner, 2016, Pleurotricha curdsi (Shi et al., 2002) Gupta et al., 2003 and Sterkiella tetracirrata Kumar et al., 2015, were isolated from soils and confirmed as new to South Korea. Oxytricha lithofera was identified based on lithosomes, cortical granules, 21-33 adoral zone membranelles, one left (14-21 cirri) and one right (15-18) marginal rows and 5 transverse cirri. Pleurotricha curdsi was identified based on the possession of 2 macronuclear nodules, 2-3 micronuclei, 46-53 adoral zone membranelles, 3 frontal cirri, 5 frontoventral cirri, 5-7 postoral ventral cirri, 2-3 right marginal rows and 5 transverse cirri. Sterkiella tetracirrata was identified with respect 4 macronuclear nodules, 3-6 micronuclei, 25-40 adoral zone membranelles, 3 frontal cirri, 3 postoral ventral cirri, 2 pretransverse cirri, one left (21-30 cirri) and one right (24-30) marginal row and 4 transverse cirri. On the basis of 18S rDNA sequence analyses, we describe the phylogenetic positions of the three species.

• Journal of Species Research
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• 제12권4호
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• pp.307-312
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• 2023

Oxytricha multilineata, Mixophrya pantanalensis pantanalensis, and Caudiurostyla sinensis were isolated from soil samples collected from Cheongju-si and Yeoju-si, confirmed as new to South Korea. Oxytricha multilineata was distinguished from other congeners by seven dorsal kineties and dorsal bristles about 15 ㎛ long. Mixophrya pantanalensis pantanalensis was characterized by five to seven lithosomes and six dorsal kineties. Caudiurostyla sinensis was characterized by colorless cortical granules present, 10-14 midventral pairs, 7-9 left and 6-9 right marginal rows and four or five dorsal kineties. We determined the ribosomal DNA sequences (including 18S rDNA, ITS1, 5.8S rDNA, ITS2, and partial 28S rDNA) from above three species. And the genetic distances were compared with their congeners.

• 한국동물학회지
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• 제20권2호
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• pp.77-92
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• 1977

棲管 갯지렁이 Schizobranchia insignis Bush의 卵子에서 일어나는 變化의 形態學的 및 生化學的 관계를 규명코자 卵子形成中 細胞學的인 變化와 卵子의 年中 分布에 대하여 연구하였다. 卵原細胞分裂 직후 난자는 卵巢에서 離脫하여 體腔囊에서 最大의 크기인 직경 6180$\\mu$ 까지 성장한다. 난자형성은 年中 계속 일어나고 있으며, 産卵期間은 1월에서 3월간이다. 난자가 最大의 크기에 달하면 그 후로는 크기에 변화가 없으며 體腔囊에 축적된다. 核仁은 직경 5-10$\\mu$의 난자에서 처음으로 나타나며 난자형성 초기단계에서 크기의 증가를 보여 직경 100-120$\\mu$의 난자에서 가장 크고, 직경 120-180$\\mu$의 기간동안 크기의 변화가 거의 없다. 仁은 최초에는 단일구획 이지만 난황물질형성 직전에 이중구획으로 나뉘어진다. 세 종류의 난황물질이 난자형성 기간중 서로 다른 시기에 형성된다. 脂質顆粒과 성분이 불확실한 타원형의 顆粒은 초기에 나타나지만, 대부분이 직경 80$\\mu$이상의 난자에서 형성된다. 단백질 난황과 皮質顆粒은 반드시 직경 80$\\mu$이상의 난자에서만 형성된다. 미세융털이 직경 80$\\mu$의 난자에서는 卵黃膜에 다량 존재하지만 직경 180$\\mu$의 난자에서는 거의 찾아 볼 수 없다.

• Applied Microscopy
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• 제2권1호
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• pp.7-15
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• 1972

난소상피에서 발생한 난원세포는 성장발육하여 제 1차 난모세포를 형성하며, 배란되어 난형성강 개구부에서 제2차 난모세포는 정자의 침입을 받은 후 2회의 감수분열을 하여 두개의 극체를 형성하고 난전핵과 정전핵이 적합하여 난할을 시작한다. 세포질의 변화 : 난원세포에서는 크기가 서로 비슷하던 미토콘드리아가 난모세포로 성장되어 감에 따라 자기증식을하여 제1차 난모세포에서는 크기가 서로 다르고 훨씬 많은 미토콘드리아가 나타난다. 편평낭상이던 소포체는 난모세포로 성장하여 세포질대사가 활발하여 짐에 따라 포상낭의 소포체로 변하며 배란후 난모세포에서는 세포질내 일부위에 층판상을 이룬다. 골지 장치는 성숙된 난모세포에서 더욱 뚜렷이 나타나며 망상의 사구체형성을 하고 그 내에 몇 개의 골지소포를 만들고 있다. 표층과립은 수정전 제1차 난모세포에서 매우 증가되어 있으나 수정후는 점차파괴되어 소실된다. 염색질은 난원세포에서 밀도가 높고 강공을 이루고 있는 이질염색질과 밀도가 낮은 소량의 진정염색질로 되어 있으며 배란전 난모세포에서는 이질염색질이 감퇴하고 진정염색질이 많아진다. 배란후 난모세포에서는 풍부한 진정염색질을 다시 가진다. 인은 난원세포에서 전자밀도가 높은 타원형이며 배란전 난모세포에서는 소실되었다가 배란후 난모세포에서는 다시 타원형의 인이 관찰된다.

• Applied Microscopy
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• 제30권1호
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• pp.61-72
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• 2000

U. unicinctus 난자를 대상으로 인공수정 후 수정막 형성에 따른 물질적 기원과 첨체반응 등에 관련된 구조변화에 대하여 광학현미경과 전자현미경을 이용하여 관찰하였다. 관찰결과에 의하면 1차 수정막의 물질은 과잉의 정자에 대한 효과적 방어 기능을 보유한 난외막 표층 기원의 물질이었으며, 2차 수정막은 피질과립의 분비에 의하여 형성되었다. 3차 수정막은 광학현미경하에서 특이한 구조의 관찰은 없었으나 전자현미경에 의한 관찰시 많은 입자상 물질들로 구성되었으며, 수정 후 60분에는 이들 입자물질의 응집에 의해서 수정막은 경과되는 것으로 관찰되었다. 1차 수정막과 난외막 표층의 유사성 그리고 1차 수정막의 형성과 미세융모의 퇴화가 동시적인 사건이라는 것은 미세융모가 U. unicinctus에서 정자의 수용체로 작용할 수 있는 것으로 추정할 수 있었다. 첨체소관에 의한 난세포막 침투시 침체 단부에서 과립상의 물질이 표층(surface coat)에 확산되었다. 첨체소관은 첨체의 기부에서 시작되고, 첨체간격을 통하여 신장되었다.

• Clinical and Experimental Reproductive Medicine
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• 제21권1호
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• pp.99-110
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• 1994

One consequence of fertilization in mammals is an increased resistance of the zona pellucida (ZP) to proteases and various chemical reagents. This phenomenon has been called 'zona pellucida hardening' (ZPH), and it is generally accepted that it is caused by the secretory products of cortical granules released by the egg at fertilization. ZP of mouse oocytes maturing in vitro in a chemically defined medium becomes progressively more resistant to solubilization by chymotrypsin ("Spontaneous" ZP hardening). In the present study, it was aimed to find the specificity of spontaneous ZPH in relation to its possible relevance to the cortical reaction and the physiological block to polyspermy. When a maturation inhibitors, cAMP analog(dbcAMP) and phosphodiesterase inhibitor (IBMX) was added to culture medium, it prevent spontaneous ZPH of mouse oocyte during in vitro culture. Thus spontaneous ZPH requires GVBD, since it is prevented by those agents, which inhibit GVBD in vitro. However, culture for 3 hours in the presence of PMA(lOng/ml), a protein kinase C activator, resulted in ZPH without GVBD, thus suggesting that ZPH may be regulated independently apart from the event of GVBD. Pretreatment of mouse oocyte with FBS result in partially inhibitory effect on subsequent spontaneous ZPH. Induction of GVBD in vivo had a inhibitory effect on the spontaneous ZPH, but subsequent spontaneous ZPH. Induction of GVBD in vivo had a inhinbitory effect on the spontaneous ZPII, but had no inhibitory effect on PMA-induced ZPH. Treatment with a microfilament formation blocker(cytochalasin-B) at 1${\mu}g$/ml concentration, resulted in the excellent inhibitory effect on spontaneous ZPH. However cytochalasin-B did not inhibit PMA-induced ZPH. Thus this suggesting that spontaneuse ZPH had a different mechanism from PMA-induced ZPH.

• 한국가축번식학회지
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• 제17권3호
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• pp.183-191
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• 1993

These experiments were carried out to investigate whether the enzyme is involved in zona hardening during normal activatin of the oocytes by sperm, and demonstrate peroxidase activity during in vitro fertilization of oocytes treated with peroxidase inhibitors(250 $\mu$M phenylhydrazine, 28mM sodium sulfite, 350mM glycine ethyl ester and 50mM sodium azide) and tyrosine analogue(12.5mM tyramine). Also, zona soluble properties of the ovarian oocytes incubated for 0, 5, 10 and 15 hr in the presence of pheylhydrazine or tyramine were studied by using $\alpha$-chymotrypsin. The results obtained from these experiments were summarized as follows ; 1. The rates of fertilizatin in control oocytes and oocytes treated with phenylhydrazine or tyramine were 69.8%, 62.3% and 88.2%, respectively. However in vitro fertilization in oocytes treated with three different peroxidase inhibitors, sodium sulfite, glycine ethyl ester and sodium azide, were not induced. The oocytes treated with phenylhydrazine had no significant effect on in vitro fertilization rate as compared to control. However there was a significantly different in fertilization between tyramine treated group and control group(P<0.01). 2. The zona solubility(t50) of control and fertilized oocytes in culture treated with phenylhydrazine or tyramine were 30.7, 26.0 and 16.3 min., respectively. Phenylhydrazine treated group and tyramine treated group had effect on inhibition of zona hardening as compared to control group. These results suggest that ovoperoxidase is involved in zona hardening during normal activation of the oocytes by sperm. 3. t50 of control oocytes and ovarian oocytes treated with phenylhydrazine or tyramine for 5, 10 and 15 hr in vitro were 14.0, 26.2 and 32.0 min., 14.5, 26.9 and 30.2 min., and 14.0, 24.3 and 31.2 min., respectively. These results suggest that zona hardening in ovarian oocytes matured for various times in vitro cannot be inhibited by peroxidase inhibitors and tyrosine analogue, that the spontaneous zona hardening incultured ovarian oocytes is not caused by the secretory products of cortical granules released during the cortical reaction, ovoperoxidase.

• 한국발생생물학회지:발생과생식
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• 제9권2호
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• pp.123-134
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• 2005

암컷 바지락, Ruditapes philippinarum의 난 형성과정 중 생식세포 발달과 난소 성숙 및 군 성숙도를 세포 및 조직학적 관찰에 의해 조사하였다. 바지락은 자웅이체이다. 난황 형성 과정 중 골지복합체, 글리코겐 입자들과 미토콘드리아들은 초기 난황 형성 단계의 난모 세포질 내에서 지방적 및 지방 과립 형성에 관여한다. 후기 난황 형성 단계 난모 세포질 내의 피질 과립, 조면 소포체 및 미토콘드리아들은 세포질 내에서 단백질성 난황 과립의 형성에 관여하였다. 이 시기에 생식상피 내의 외인성 지질 과립상 물질들과 글리코겐 입자들이 난황막의 미세 융모를 통해서 난모 세포질 내로 통과해 들어간다. 산란기는 6월 초에서 10월 초 사이로 연중 한 번이었으며, 주 산란은 해수 수온이 대략 $20^{\circ}C$인 7월과 8월 사이에 일어났다. 본 종의 생식주기는 초기 활성기($1{\sim}3$월), 후기 활성기($2{\sim}5$월), 완숙기($4{\sim}8$월), 부분 산란기($5{\sim}10$월), 퇴화 및 비활성기($8{\sim}2$월)의 연속적인 5단계로 구분되었다. 각장 $15.1{\sim}20.0\;mm$인 암컷 조개의 군 성숙도 비율(%)은 52.6%(군 성숙도 50%는 각장 17.83mm)이었고, 각장 25.1mm 이상인 조개는 100%의 군 성숙도를 보였다.

• 대한치과보철학회지
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• 제29권2호
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• pp.225-243
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• 1991

In recent years immediate implantation has been tried by a few clinicians. This study placed IMZ implants in the rabbit femur with and without bony defects around the implant for simulating fresh extraction site. And one group with bony defects used porous hydroxyapatite ganules(HA) to fill if and the other group left the bony defects around the implant. The purpose of this study was to compare the shear bond strength and the bony contact and formation around the implant. Fifteen rabbits were divided into three groups and placed 10 IMZ implants to each group. Implant sites were surgically prepared with IMZ drills kit and implants were placed(Control), artificial bony defect was created with Apaceram drills kit around the implant sites and implants were placed(Experimental I), bony defect was filled with porous hydroxyapatite granules(Experimental II). Thereafter, rabbits were sacrificed at 8th week and specimens were prepared and pushout tested for shear bond strength of bone-implant interface immediately. Undecalcified and decalcified specimens were prepared with Vilanueva and hematoxylin-eosin stain for light microscopic finding. The results of this study were as follows. 1. In the control group, mean shear strength of bone-implant interface was $2.614{\pm}0.680$ MPa, experimental I was $0.664{\pm}0.322$ MPa, and experimental II was $2.281{\pm}0.606$ MPa. There was significant difference between control and experimental I, between experimental I and experimental II, but did not show significant difference between control and experimental II statistically. 2. In the bony formation surrounding IMZ implant of the three groups, that of cortical bone is more advanced than cancellous bone area. 3. In the histological findings of undecalcified specimens, control and experimental II showed more than 50% of bony or osteoid formation at the bony-implant interface. 4. In the histological findings of undecalcified specimens, experimental I showed less than 50% of bony or osteoid formation at the interface, and observed partial bony defect in the coronal zone. 5. In the experimental II group, were observed direct bony contact to hydroxyapatite granules, and infiltration of a few giant cells. 6. No inflammatory responses were seen around the titanium implants and the hydroxyapatite granules.