• Parasites, Hosts and Diseases
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• 제37권1호
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• pp.5-11
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• 1999

Three species of the families Viviparidae and Pleuroceridae, the first intermediate host of paragonimiasis, metagonimiasis and echinostomiasis were studied cytologically. The observed diploid chromosome number was as follows: Semisulcospira libertina 36, S. dolichostoma 34, and Viviparus rivularis 64. The mitotic chromosome complement of S. libertina has nine metacentric pairs and nine submetacentric pairs, and S. dolichostoma has three metacentric pairs and 14 submetacentric pairs of chromosomes. Viviparus rivularis showed two metacentric pairs and 30 submetacentric pairs of chromosomes.

• 한국균학회지
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• 제14권4호
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• pp.253-256
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• 1986

fusarium속(屬)에 속하는 3 종(種)인 F. solani, F. moniliforme, F.cocophilum을 실험재료로 하여 그들의 균사내(菌絲內)에서 일어나는 핵분열(核分裂)을 관찰하고, 그들의 염색체수(染色體數)를 확인하였다. Fusarium속(屬)의 핵분열(核分裂)은 생장(生長)하고 있는 끝부분(hyp-hal tip)에서 좀 더 관찰이 잘 되었고 염색체(染色體)의 형태(形態)는 대체로 점(點)(dot)모양이었으며, 확인한 염색체(染色體)의 수(數)는 F. solani는 n=8, F. moniforme는 8, F. cocophilum은 n=6개였다.

• 한국동물학회지
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• 제39권1호
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• pp.75-88
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• 1996

OTF9-63 (OTF9)와 P19S1O1A1 (P19) 배종양 세포들의 체세포에 존재하는 불화성 X 염색체의 재활성과 유발 능력을 조사하였다. 배종야 세포와 체세포들의 융합에 의해 얻어진 HATr 클론들의 형태, 염색체 복제 양상을 비롯하여 X 염색체에 존재하나 그 위치는 상당히 먼 유전자들인 Hprt와 Pgk-1의 발현 양상을 분석한 결과, OTF9 세포는 불활성 X 염색체를 재활성화 시킬 수 있는데 반해 P19 세포는 불가능한 것으로 나타났다. 또한, 모든 유합세포는 장기간 배양되었을 때 성염색체의 수가 감소하였으며, 결국 1:2의 성염색체:상염색체의 비율을 나타내었다. 배종양 세포-체세포 융합세포의 이용은 초기 배발생 과정에서 시작되어 난자형성 과정의 감수분열 전까지의 유지되는 X 념색체의 재활성화 기작을 연구하기 위한 실험 방법을 제공한다.

• 생명과학회지
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• 제11권4호
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• pp.354-361
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• 2001

Chromosomal characteristics of New Zealane White rabbit was studied at meiosis and mitosis. The meiotic chromosomal preparations were mad with the modified air-drying method and karyotype analysis was performed with the G-banding technique, using isolated mitotic metapase chromosomes of the New Zealand White rabbit. Chromosomes, sex vesicles and centromeres could be classified in the zygotene and the pachytene of the meiosis I. The hair-like processes projecting laterally from the axes of bivalent chromosomes at the mid-to-late pachytene were observed and made the appearance of the lampbrush chromosome structure. Chromosomes could be classified onthe basis of the numbers and locations of chiasma in the diakinesis. Twenty-one autosomal bivalents and a single unequal terminally associated X-Y bivalent were observe during the late prophase and the metaphase of the meiosis I. Most of the bivalent types observed in the New Zealand White rabbit spermatrocytes were 1CH, 1TAl, and 2TA bivalents. The mean chiasma frequency(CF) of the male New Zealand White rabbit was 30.2 and it was found that the CF value tended to decrease through diakinesis and the metaphase I. The karyotype of the New Zealand White rabbit was a male chromosome number of 44(2n=44) comprising 8 pairs of metacentric, 9 pairs of submetacentric, 4 pairs o acrocentric autosomes, metacentric X chromosome and acrocentric Y chromosome.

• Clinical and Experimental Reproductive Medicine
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• 제18권2호
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• pp.223-231
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• 1991

During the years 1984 to 1989, in order to determine of chromosome abnormalities are associated with recurrent spontaneous abortions, cytogenetic studies were performed 384 couples. Abnormal karyotypes were found in 51(13.3%) couples. There was no apparent relation with the number of abortions. The abnormalities were as follows: 17(4.4%) balanced translocation; 15(3.9%) mosaicisms; 17(4.4%) pericentric inversion; 2(0.5%) addition or isochromosome. Chromosome abnormalities were observed in 34(67%) of the wives and 17(33%) of the husbands. In addition, we detected polymorphic variants of chromosomes in 89(23.2%) subjects. Reciprocal translocations(13/17) were more common than the robertsonian type(4/17). All of the mosaicisms were associated with the sex chromosomes in 10 females and 5 males subjects. Pericentric inversions were most common in chromosome 9. Compared to previously studied general populations, significantly higher frequencies of translocations, mosaicisms and inversions were found in couples with repetitive spontaneous abortion. This suggests that couples should have chromosome studies after two or more abortions.

• 한국과학교육학회지
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• 제13권2호
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• pp.219-229
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• 1993

The purpose of this study is to investigate college science students' and science teachers' understanding of chromosomal behavior in the context of cell division. The research problems were as follows: 1. What is the level of college science students' understandings of chromosomal behaviors? 2. What is the level of science teachers' understandings of chromosomal behaviors? 3. What is the level of understanding by grade and major area? The sample consisted of 28 sophomore, 17 junior and 23 senior biology students; and 23 middle school science teachers and 14 high school biology teachers. The instrument of the study was a short answer required paper and pencil test. The results of the study were as follows: 1) About 15 percent of the sample could not count the number of chromosome in a cell in appropriate. 2) Seventy percent of the students, and 80 percent of the teachers identified homologous chromosomes as ones with the similar shape and size, and 30 percent of the whole sample could not pair two homologous chromosomes. 3) About 70 percent of the students and 30 percent of the teachers could not mark corresponding allele on chromosome. 4) Biology major students showed higher understanding of overall chromosomal behaviors than non Biology students. Based upon the results, some implications were made. The major one was a development of a teaching model in which students can improve the ability to connect chromosome theory to mendelian genetics.

• Clinical and Experimental Reproductive Medicine
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• 제13권2호
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• pp.161-174
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• 1986

A chromosomal study was performed in a total of 162 urological patients during past 2$2{\frac{1}{2}}$ years (Feb. 1984 - Aug. 1986). Of these 78(48%) patients had abnormal chromosome complements. Among all patients with chromosome abnormalities, 88% (69/78) had aberrations of chromosome number, 8% (6/78) had aberrations of chromosome structure and 4% (3/78) had aberrations of both. 90% (65/72) of numerical abnormality was Klinefelter's syndrome and the structural abnormality rate (5.6%, 9/162) was less than that (6.99%) of general population. The chromosomal study was mandatory for the detection of intersex in small testes or hypospadias with cryptorchism or clitoromegaly or bilateral cryptorchism. But unilateral cryptochism or hypospadias with normal scrotal testes was not thought to be indication of the chromosomal study if the external genitalia are otherwise quite normal.

• 생태와환경
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• 제42권2호
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• pp.192-199
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• 2009

Freshwater green algae are one of the important sources of bioenergy in the future. Spirogyra is a conjugating filamentous zygnematacean green algal genus that is widely distributed worldwide with more than 400 species. Despite its widespread occurrence throughout the world, cytological studies of the genus have been limited. We investigated karyological features and chromosome numbers for seven Korean Spirogyra species. Most of the species examined in the present study showed significant karyological features, inner organization of nucleolus, heavily stainable nucleolar substance and the diffuse-centric nature of chromosomes, typical of the Conjugales. Chromosome number ranged from n=12 in S. varians to n=38 in S. africana. Aberrant cytokinesis resulted in binucleate and tetranucleate cells, which sometimes provide cytological explanation for different morphology and ploidal changes in clonal culture of Spirogyra or even different cells within the same filament. The present chromosome data also substantiates the earlier held assumption that aneuploidy must have been the chief driving force for speciation and evolution of the genus Spirogyra.

• Toxicological Research
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• 제13권3호
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• pp.297-301
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• 1997

In order to evaluate the mutagenic potential of CJ-50001 (recombinant human granulocytecolony stimulating factor), 3 sets of mutagenicity tests were performed. In the reverse mutation test using Salmonella typhimurium TA1535, TA1537, TA98 and TA100, CJ-50001 did not increase the number of revertant at any of the concentration tested in this study (500, 250, 125, 62.5 and 31.3 $\mu\textrm{g}$ plate). CJ-50001, at the doses of 200, 100 and 50 $\mu\textrm{g}$ /ml, did not increase the number of cells having structural or numerical chromosome aberration in cytogenetic test using Chinese Hamster Lung cells. In mouse micronucleus test, no significant increase in the occurrence of micronucleated polychromatic erythrocytes was observed in ICR male mice intraperitoneally administered with CJ-50001 at the doses of 5, 2.5 and 1.25 mg/kg. These results indicate that CJ-50001 has no mutagenic potential in these in vitro and in vivo systems.

• 한국가축번식학회지
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• 제10권1호
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• pp.36-41
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• 1986

These experiments were carried out to obtain basic information necessary for sexing embryos by chromosomal analysis. To observe metaphase chromosomes, all embryos developed to blastocysts were cultured in Ho, pp. & Pitts' medium containing 0.001% Colcemid under the gas phase of 5% CO2 in air at 37$^{\circ}C$ for 2 hours. The sex chromosome of mouse embryos shown normal development after culture in medium containing H-Y antiserum (10%, v/v) and complement (20%, v/v) also was confimed by chromosomal analysis. The results obtained in these experiments were summarized as follows: 1. Among 89 mouse blastocysts, the number of embryos identified to have XX and XY chromosome was 22(25%) and 25(28%), respectively and 42(47%) embryos were not identified. 2. Of total 40 mouse balstocysts cultured in medium containing H-Y antiserum and complement, 23(58%) embryos which were able to be discriminated their sex chromosomes were identified to be XX bearing embryos. 3. Sex chromosomes of a number of embryos subjected to chromosomal analysis were not identified. This result may be due to absence or poor quality of metaphase spreads.