• 생명과학회지
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• 제19권4호
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• pp.436-441
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• 2009

B23/nucleophosmin은 핵인 단백질로서 외부 스트레스에 의해 핵인에서 핵으로 이동하게 된다. 이러한 세포 내 위치변화는 MDM2에 의한 p53단백질의 안정화에 영향을 미친다. 노화세포는 거대한 단일 핵인을 가지고 있으며, 외부 스트레스에 의해 p53 안정성이 감소한다. 그렇지만, 노화세포에서 어떠한 기전에 의해 p53의 불안정성이 증가하는 지는 아직 밝혀진 바가 없다. 따라서 본 연구에서는 노화세포에서 B23/nucleophosmin과 p53간의 상호 관련성을 조사하여 p53 안정성에 미치는 영향을 규명하고자 하였다. 본 연구에서는 IMR90세포주에 ras oncogene을 과발현시켜 노화세포를 유도하였다. 핵인 스트레스에 의해 노화세포 내 p53 단백질 발현은 감소하였으나, B23/nucleophosmin 단백질의 발현은 정상세포와 큰 차이가 없었다. 그렇지만, 두 단백질의 세포 내 위치는 노화세포에서 변화가 있었다. 즉, 정상세포와 달리, 노화세포에서는 스트레스에 의해 핵 내 p53발현이 증가하지 않았으며, B23/nucleophosmin은 핵 내로 이동하지 않고, 핵인에 그대로 머물러 있었다. 노화세포에서 MDM2와 p53간 상호결합이 안정적으로 유지된대 비하여, p53과 B23/nucleophosmin간의 상호결합은 감소하였다. 이러한 결과는 노화세포에서 핵인 스트레스에 의한 p53단백질의 안정성은 B23/nucleophosmin 결합이 감소하여 일어나는 것으로 해석된다.

• 한국양식학회지
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• 제18권3호
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• pp.167-172
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• 2005

능성어 정자의 안정적 확보를 위하여 MT $0.5{\sim}2.0mg/kg$ BW를 어체 근육내 삽입하여 성전환을 유도하였다 사용한 실험어는 전장 $41.0{\pm}1.3cm$, 체중 $1.4{\pm}0.1kg$이었다. 실험 시작시 능성어 생식소는 주로 gonia cells과 주변인기 단계 난모세포를 가지고 있었다. 실험 종료시 대조구의 생식소는 실험 시작시와 유사하였다. 0.5 mg MT/kg BW 처리구 생식소는 실험 종료 때 소엽내강에 정원세포와 정세포 그리고 정자무리들이 대부분 차지하고 기부에 수정관이 형성되었으나, 일부 어린 난모세포들이 산재하였다. 1.0과 2.0 mg MT/kg BW처리구는 소엽내강과 기부의 수정관에 정자무리들로 가득 차 있었다. 정자는 $1.0{\sim}2.0mg$ MT/kg BW 처리구에서 얻을 수 있었다. MT 처리구의 T혈중농도는 대조구보다 2주 후부터 6주 후까지 높았으나(P<0.05), 배정이 가능한 8주째 대조구와 유사하였다(P>0.05). 11-KT 혈중농도는 MT 1.0처리구는 2주 후부터 6주째까지, 2.0 mg MT/kg BW 처리구는 2주 후부터 실험 종료 때까지 대조구 보다 높았다(P<0.05). $E_2$는 모든 실험어 일부에서 검출되었다.

• 식물조직배양학회지
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• 제25권6호
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• pp.453-475
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• 1998

During the 100 years since the initial discovery of meiotic phenomenon many brilliant aspects have been elucidated, but further researches based on light microscopy alone as an experimental tool have been found to have some limits and shortcomings. By the use of electron microscopy and armed with the advanced knowledges on modern genetics and biochemistry it has been possible to applu molecular technology in gaining information on the detailed aspects of meiosis. As synapsis takes place, a three-layered proteinous structure called the synatonemal complex starts to form in the space between the homologous chromosomes. To be more precise, it begins to form along the paired chromosomes early in the prophase I of meiotic division. The mechanism that leads to precise point-by-point pairing between homologous chromocomes division. The mechamism that leads to precise point-by-point pairing between homologous chromosomes remains to be ascertained. Several items of information, however, suggest that chromsome alignment leading to synapsis may be mediated somehow by the nuclear membrane. Pachytene bivalents in eukaryotes are firmly attached to the inner niclear membrane at both termini. This attached begins with unpaired leptotene chromosomes that already have developed a lateral element. Once attached, the loptotene chromosomes begin to synapse. A number of different models have been proposed to account for genetic recombination via exchange between DNA strands following their breakage and subsequent reunion in new arrangement. One of the models accounting for molecular recombination leading to chromatid exchange and chiasma formation was first proposed in 1964 by Holliday, and 30 years later still a modified version of his model is favored. Nicks are made by endomuclease at corresponding sites on one strant of each DNA duplex in nonsister chromatid of a bivalent during prophase 1 of meiosis. The nicked strands loop-out and two strands reassociate into an exchanged arrangement, which is sealed by ligase. The remaining intact strand of each duplex is nicked at a site opposite the cross-over, and the exposed ends are digested by exonuclease action. Considerable progress has been made in recent years in the effort to define the molecular and organization features of the centromere region in the yeast chromosome. Centromere core region of the DNA duplex is flanked by 15 densely packed nucleosomes on ons side and by 3 packed nucleosomes on the other side, that is, 2000 bp on one side and 400 400 bp in the other side. All the telomeres of a given species share a common DNA sequence. Two ends of each chromosome are virtually identical. At the end of each chromosome there exist two kinds of DNA sequence" simple telpmeric sequences and telpmere-associated sequencies. Various studies of telomere replication, function, and behabior are now in progress, all greatly aided by molecular methods. During nuclear division in mitosis as well as in meiosis, the nucleili disappear by the time of metaphase and reappear during nuclear reorganizations in telophase. When telophase begins, small nucleoli form at the NOR of each nucleolar-organizing chromosome, enlarge, and fuse to form one or more large nucleoli. Nucleolus is a special structure attached top a specific nucleolar-organizing region located at a specific site of a particular chromosome. The nucleolus is a vertical factory for the synthesis of rRNAs and the assenbly of ribosome subunit precursors.sors.

• 한국양식학회지
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• 제9권1호
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• pp.73-81
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• 1996

농어목 어류인 Caesio diagramma의 생식주기를 밝히기 위하여 난모세포의 발달과정을 조직학적 방법으로 관찰하였다. 난모세포의 발달과정은 염색인기, 주변인기, 유구기, 제1차 난황구기, 제2차 난황구기 및 제3차 난황구기의 6단계로 구분되었다. 염색인기와 주변인기의 난모세포는 연중 관찰되었으며, 난모세포 발달과정에서의 특징은 난소 내에서 유구가 초기에 형성되며, PAS 염색 결과 난황포는 타어류에 비하여 크기가 작았고 양도 적었다. 4월에 채집된 어류의 난소에서는 난황 형성기의 난모세포가 출현하기 시작하였다. $5\~6$월의 난소에서는 제3차 난황구기 난모세포가 관찰되었으며, 연중 가장 높은 비율을 나타냈다. 또한, 이 시기부터 난소의 일부에서는 배란을 마친 여포와 퇴화중인 난모세포도 다수 관찰되었으며, 7월까지 이어졌다. 9월 이후의 난소에서는 난황 형성기의 난모세포가 관찰되지 않았으며, 12월까지 염색인기 및 주변인기의 난모세포가 주류를 이루었다. 생식소중량지수(GSI)와 간중량지수(HSI)는 4월부터 증가하기 시작하여, $5\~6$월에 최고치에 도달하였으며 GSI와 HSI의 변화는 난모세포의 발달과정과 일치하였다. 따라서 C. diagramma의 주산란기는 $5\~6$월이며, 난소의 발달과정과 여러 형태의 여포가 존재하는 점으로 미루어, 본 종은 비동기발달형의 난소를 가지며 다회산란 어류에 속한다.

• 한국수산과학회지
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• 제39권3호
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• pp.297-302
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• 2006

황점볼락, Sebastes oblangus의 인공종묘의 성분화 과정 및 성결정을 조사하기 위해 출산 직후부터 370일령까지 조사하였다. 출산 직후 난황기 자어(7.10-7.77 mm)에서 시원생식세 포와 생식융기는 분리된 채 중신관과 장간막 사이에 나타났고, 출산 후 5일령 전기자어(7.12-9.68 mm)에서는 서로 융합하였으며, 출산 후 45일령 후기자어(18.6-20.4 mm)까지는 미분화 생식소 상태였다. 출산 50일 치어(20.0-24.5 mm)에서 생식소 전단부에서 양쪽 끝의 체세포 조직이 분열 신장되어 난소의 분화가 시작되어 60일 치어(25.5-32.0 mm)에서 완전 한 난소강이 형성되었다. 출산 80일령 치어(37.3-47.2 mm)의 난소에서 난원세포가 감수분열을 개시하여 염색인기 난모세포(chromatin nucleolus oocyte) 로 발달하기 시작하였다. 이 후 일령이 증가하여 130일령(68.0-86.0 mm)에서 주변인기(perinucleolus stage)의 난모세포가 나타났으며, 출산 후 370일령(101.0-116.0 mm)에서 전난황형성기의 난모세포들이 출현하였다. 황점볼락 인공종묘의 성비 조사결과 난소분화 완료 후에 암컷만 나타나 출산후 100일까지 자연수온보다 높은 수온에 의해 전암컷화 된 것으로 추정된다.

• 한국수산과학회지
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• 제39권5호
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• pp.404-409
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• 2006

This study investigated the reproductive cycle of the female hairychin goby, Sagamia geneionema, histologically. The fecundity of female hairychin goby ranged from 1,002 to 1,240 eggs when they reached a total length of 9.1-10.0 cm. Fecundity is related to total length. The gonadosomatic index (GSI) increased from December (1.87$\pm$0.46) and reached a maximum in April (11.57$\pm$1.92). The histological changes in the ovary were correlated with the GSI. Oocytes at the chromatin-nucleolus and peri-nucleolus stages were observed in the ovary year-round. In December, oocytes containing yolk appeared in the ovaries of a few fish. Most oocytes appearing in January were at the yolk globule stage. The frequency of oocytes appearing at the yolk globule stage from January to March was higher than in other months. Subsequently, empty follicles and atretic oocytes were observed in the ovaries in May. Based on the histological observations of gonad development and the monthly change in the GSI, the reproductive cycle was classified into the following successive stages: growing (October to November), mature (December to January), ripe and spawning (February to April), and degenerative and resting (May to September) stages. The histological observations of ovaries during the spawning period indicate that this species is a multiple spawner with abbreviated iteroparity based on the developmental pattern of oocytes.

• 한국어류학회지
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• 제20권4호
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• pp.255-262
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• 2008

멸종위기야생동식물 1급으로 지정된 꼬치동자개, Pseudobagrus brevicorpus의 종복원을 위해 인위적인 교배를 통하여 획득한 자치어를 대상으로 성분화 과정을 조사하여 성적임성 여부를 확인하였다. 부화 후 4~5일째 자어에서 생식융기 1쌍이 장과 중신관 사이에서 관찰되었고, 그 후 유사분열이 활발히 진행되었다. 부화 후 20일째 치어에서 난원세포의 출현으로 난소 분화가 시작되었으며, 부화 후 30~40일째를 거치면서 염색인기와 주변인기의 난모세포로 성장하였다. 난황은 부화 후 80일째의 자어에서 생성되기 시작하였고, 부화 후 100일째가 되어 eosin에 염색되는 난황구가 생성되었다. 이후 난모세포는 난황이 지속적으로 축적되면서 세포의 크기와 수가 증가하기 시작하였고, 부화 후 약 10개월째에는 난막과 여포세포층에 의해 둘러싸여진 난모세포로 분화하였다. 한편 정소는 부화 후 25일경 치어에서 분화되기 시작하였고, 40일경 유사분열을 통해 정원세포를 둘러싸는 포낭을 형성하였다. 부화 후 100일째가 되면 정소는 정소엽 구조를 형성하였고 hematoxylin에 매우 진하게 염색되는 정모세포로 분화하였다. 부화 후 7개월째 치어의 정소엽 내부에 정세포가 출현한 이후, 부화 후 만 1년을 경과한 치어에서 최초로 성숙한 정자가 출현하였다. 위 결과를 바탕으로 인공적으로 부화된 꼬치동자개 자치어의 성분화는 다른 종에서 보이는 것과 같이 정상적인 발달을 보인다고 판단되었다.

• Parasites, Hosts and Diseases
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• 제25권2호
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• pp.99-109
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• 1987

The present study was carried out to examine the effect of a calcinogen, aflatoxin B1 on the ultrastructural changes of ciliary epithelial cells in mice infected with Clonerchis sinensis. A total of 93 male albino mice(BALB/c strain) was divided into 3 groups; group I, treated with 1.0 ppm aflatoxin Bl for 12 weeks; group II, given 50 C. sinensis n;etacercariae, and group III, given 50 metacercariae and treated with 1.0 ppm aflatoxin Bl for 12 weeks. Three mice served for untreated-uninfected controls. From 4 weeks after the treatsment and/or in(ection, three mice from each group were sacrificed at 4 week intervals up to the 40th week, and their hepatobiliary tissues were prepared for transmission electron microscopy. The most prominent ultrastructural changes in group I were remarkable enlargement of nuclear size, separation of nucleolus, dispersed chromatin granules in nuclei and increased dense granules along the inner membrane of nuclei. In the cytoplasm there was slight proliferation of mitochondria and endoplasmic reticulum (ER) at earlier stage. At the 12th week separation of fibrillar and granular components of the nucleolus was a characteristic finding. As the time elapsed, epithelial cells showed fiattened-cuboidal form and a tendency of atrophy. Most of the nuclei were elongated and polygonal in shape. In group II the appearance of elaborate interwoven folds of lateral cytoplasm forming a labyrinth of interconnected intercellular space and variety in nuclear shape were the prominent fadings at earlier stage. The cytoplasm showed slight proliferation and dilatation of mitochondria and ER, and a small number of mucin droplets. In the basement membrane scanty fibrous cells were seen. With time, variety in nuclear shape, marked proliferation and dilatation of rough ER and some collagen fibrils were demonstrated. Other features of intracellular organelles and mucin droplets persisted. In group III cuboidal epithelial cells showed their remarkably enlarged and irregular nuclei, increased chromatin granules in the nuclei, separated nucleoli, proliferated and dilated rough ER. With time, sequestered mitochondria showed blob-like evaginations which lacked cristae and dense matrix, and were limited by a single membrane. Since the 20th week, microvilli were relatively scanty and poorly developed. Organelles and inclusions in the cytoplasm of metaplastic cells were poor. Nuclei were variable in shape. The nlost prominent changes at later stage were separation of nuclei from the cytoplasm, and appearance of numerous and irregularly angled electron dense granules in the nuclei.

• Clinical and Experimental Reproductive Medicine
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• 제32권3호
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• pp.269-277
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• 2005

Objectives: Previously, we sought to compile a list of genes expressed during early folliculogenesis by using cDNA microarray to investigate follicular gene expression and changes during primordialprimary follicle transition and development of secondary follicles (Yoon et al., 2005). Among those genes, a group of genes related to the cell size growth was characterized during the ovarian development in the present study. Methods: We determined ovarian expression pattern of six genes related to the cell size growth (cyr61, emp1, fhl1, socs2, wig1 and wisp1) and extended into CCN family (${\underline{c}}onnective$ tissue growth factor/${\underline{c}}ysteine$-rich 61/${\underline{n}}ephroblastoma$-overexpressed), ctgf, nov, wisp2, wisp3, including cyr61 and wisp1 genes. Expression of mRNA and protein according to the ovarian developmental stage was evaluated by in situ hybridization, and/or semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and immunohistochemistry, respectively. Results: Among 6 genes related to the cell size growth, cyr61 and wisp1 mRNA was detected only in oocytes in the postnatal day5 mouse ovaries. cyr61 mRNA expression was limited to the nucleolus of oocytes, while wisp1 was expressed in the cytoplasm and nucleolus of oocytes, except nucleus. cyr61 mRNA expression, however, was found in granulosa cells from secondary follicles. The rest 4 genes in the cell size growth group were detected in oocytes, granulosa and theca cells. Cyr61 and Wisp1 proteins were expressed in the oocyte cytoplasm from primordial follicle stage. Especially, Cyr61 protein was detected in pre-granulosa cells, Wisp1 protein was not. By using RT-PCR, we evaluated and decided that Cyr61 protein is produced by their own mRNA in pre-granulosa cells that was not detected by in situ hybridization. cyr61 and wisp1 genes are happen to be the CCN family members. The other members of CCN family were also studied, but their expression was detected in oocytes, granulose and theca cells. Conclusions: We firstly characterized the ovarian expression of genes related to the cell size growth and CCN family according to the early folliculogenesis. Cyr61 protein expression in the pre-granulosa cells is profound in meaning. Further functional analysis for cyr61 in early folliculogenesis is under investigation.

• Asian-Australasian Journal of Animal Sciences
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• 제32권7호
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• pp.956-965
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• 2019

Objective: The main goal of this study was to provide a morphological indicator that could be used to select high-quality oocytes of appropriate meiotic and developmental capabilities in pig. The higher quality of immature oocytes, the higher success rates of in vitro maturation (IVM) and in vitro fertilization (IVF). Thus, prior to the IVM culture, it is important to characterize oocytes morphologically and biochemically in order to assess their quality. Two of the largest indicators of oocyte quality are the presence of cumulus cells and status of chromatin. To investigate the effects of porcine oocyte chromatin configurations on the developmental capacity of blastocysts, we assessed oocyte chromatin status according to follicle size and measured the developmental potency of blastocysts. Methods: To sort by follicle size, we divided the oocytes into three groups (less than 1 mm, 1 to 3 mm, and more than 3 mm in diameter). To assess chromatin configuration, the oocytes were assessed for their stages (surrounded nucleolus [SN] germinal vesicle [GV], non-surrounded nucleolus [NSN] GV, GV breakdown, metaphase I [MI], pro-metaphase II [proMII], and metaphase II [MII]) at different maturation times (22, 44, and 66 h). To assess the development rate, oocytes of each follicle size were subjected to parthenogenetic activation for further development. Finally, GV oocytes were grouped by their chromatin configuration (SN, SN/NSN, and NSN) and their global transcriptional levels were measured. Results: SN GV oocytes were more suitable for IVF than NSN GV oocytes. Moreover, oocytes collected from the larger follicles had a greater distribution of SN GV oocytes and a higher developmental capacity during IVM, reaching MII more quickly and developing more often to blastocysts. Conclusion: Porcine oocytes with high-level meiotic and developmental capacity were identified by analyzing the relationship between follicle size and chromatin configuration. The porcine oocytes from large follicles had a significantly higher SN status in which the transcription level was low and could be better in the degree of meiotic progression and developmental capacity.