• 한국작물학회지
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• 제43권2호
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• pp.120-123
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• 1998

Based on the co-linearity in the Triticeae, comparative RFLP analysis of 2M chromosome of Ae. comosa Sibth et Sm. was performed with 2MS and 2M additional lines of Triticum aestivum L. cv. Chinese Spring. Among the wheat RFLP probes conserved in the short arms of wheat chromosome 2, those above psr912 were located on the long arms of 2M in Aegilops comosa. The rest probes on the short arm and all the probe sequences on the long arm of group 2 chromosome in wheat were conserved on the equivalent chromosomal position in Aegilops comosa. So, it is apparent that some chromosomal segment from the short arm had been transferred to long arm while reconstructing 2M chromosome relative to wheat chromosomes. The break-point was located between psr912 and psr131 of the short arm. This rearrangement of chromosome 2M might be a molecular evidence of the M genome speciation from an ancestral type.

• Journal of Radiation Protection and Research
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• 제33권4호
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• pp.161-166
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• 2008

극저주파 전자기장의 노출과 여러 암 발생과의 연관성을 구명하기 위해 많은 연구가 이루어지고 있으나 아직도 결론을 내리기에는 논란이 있다. 본 연구에서는 극저주파 전자가장이 소핵, 이수성 및 염색제 재배열과 같은 염색체 손상을 유도하는지 여부와 bleomycin (BLM) 에 악해 유발된 염색체 손상 빈도를 증진시키는지 확인하기 위해 사람 섬유아세포에 BLM과 0.8mT 세기의 극저주파 전자가장을 노출시킨 후 micronucleus - centromere 분석을 수행하였다. BLM의 농도에 따라 소핵, 이수성 및 염색체 재배열의 빈도가 유의하게 증가하 였으며(p<0.05), 0.8 mT 세기의 극저주파 전자기장은 단독으로 사람 섬유아세포에 염색체 손상을 유도하지 않았으나, BLM에 의해 유발된 소핵과 이수성의 빈도를 유의하게 증가시켰다(p<0.05). 따라서 극저주파 전자기장은 단독으로 사람 섬유아세포에 유전독성을 일으키지 않으나 BLM에 의한 소핵과 이수성 빈도를 증폭하는 효과를 나타낸다.

• Molecules and Cells
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• 제43권5호
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• pp.448-458
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• 2020

T-DNA insertional mutations in Arabidopsis genes have conferred huge benefits to the research community, greatly facilitating gene function analyses. However, the insertion process can cause chromosomal rearrangements. Here, we show an example of a likely rearrangement following T-DNA insertion in the Anti-Silencing Function 1B (ASF1B) gene locus on Arabidopsis chromosome 5, so that the phenotype was not relevant to the gene of interest, ASF1B. ASF1 is a histone H3/H4 chaperone involved in chromatin remodeling in the sporophyte and during reproduction. Plants that were homozygous for mutant alleles asf1a or asf1b were developmentally normal. However, following self-fertilization of double heterozygotes (ASF1A/asf1a ASF1B/asf1b, hereafter AaBb), defects were visible in both male and female gametes. Half of the AaBb and aaBb ovules displayed arrested embryo sacs with functional megaspore identity. Similarly, half of the AaBb and aaBb pollen grains showed centromere defects, resulting in pollen abortion at the bi-cellular stage of the male gametophyte. However, inheritance of the mutant allele in a given gamete did not solely determine the abortion phenotype. Introducing functional ASF1B failed to rescue the AaBb- and aaBb-mediated abortion, suggesting that heterozygosity in the ASF1B gene causes gametophytic defects, rather than the loss of ASF1. The presence of reproductive defects in heterozygous mutants but not in homozygotes, and the characteristic all-or-nothing pollen viability within tetrads, were both indicative of commonly-observed T-DNA-mediated translocation activity for this allele. Our observations reinforce the importance of complementation tests in assigning gene function using reverse genetics.

• Radiation Oncology Journal
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• 제11권1호
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• pp.43-50
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• 1993

방사선에의 노출은 염색체 이상을 유발하는 원인으로 널리 인식되고 있으나 in vivo상태에서 방사선 조사 후 발생되는 염색체 이상의 종류와 빈도 규명은 드물었다. 이에 본 연구에서는 암 환자에서 방사선 치료 전 및 후에 말초혈액 임파구의 염색체 변이를 비교 관찰하고 방사선 조사에 의해 암 환자세포에서 나타나는 염색체 이상에서 절단점의 분포가 암 발생과 밀접한 연관이 된 유전자 및 염색체의 재조합이 자주 일어나는 부위와 연관관계 가 있음을 규명하고자 하였다. 25예의 암 환자에서 방사선 치료가 시작되기 전과 $4000\~7000cGy$의 근치적 방사선치료가 끝난 직후 말초 혈액을 채취하여 임파구를 배양후 G-분염법을 이용하여 염색한 후 환자마다 방사선치료 전후로 각각 30개씩의 증기상을 관찰하였다. 치료전에 염색체 이상을 나타낸 세포 분열 중기상의 빈도는 $4.93\%$로 정상 대조군 집단의 빈도 $2\%$보다 높았다(p<0.05). 방사선 치료후 염색체 이상 세포의 빈도는 $22.13\%$로 치료전에 비해 매우 중가되었다(p<0.01). 또한 세포 중기상당 이상 염색체의 수도 치료전과 후가 각각 1.49및 2.14로 치료후 증가 되었다(p<0.05). 염색체 이상의 종류는 major chromosomal aberration 특히 구조적 이상의 빈도가 치료전보다 후에 $65.45\%$에서 $88.45\%$로 증가되었고 minor structural abnormality와 수적 변이의 빈도는 감소되었다. 방사선 치료후 염색체 절단점의 수가 2개 이상인 경우가 단일 절단점을 가진 이상에 비해 증가되었다. 절단점의 분포에 있어서는 암세포에서 가장 흔한 이상을 나타내는 1번 및 3번 염색체와 절단점의 증가가 암 발생관 연관된다고 보고된 8번 및 11번 염색체에서 본 연구결과 기대치 이상의 절단점의 분포를 보이고, 암 세포에서 드물게 이상을 나타내는 13, 15및 21번 염색체에서는 기대치 보다 감소된 절단점의 분포를 보였다. 따라서 방사선 치료 후 염색체 이상의 빈도는 증가되었으며 방사선 조사에 의해 나타나는 염색체의 절단점의 분포는 암 발생과 밀접한 연관이 된 유전자 및 염색체의 재조합이 자주 일어나는 부위와 밀접한 연관 관계가 있음을 보여 주었다.

• 한국어류학회지
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• 제29권2호
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• pp.89-93
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• 2017

최근 신종으로 발표된 동방자가사리 Liobagrus hyeongsanensis의 핵형 분석을 위해 경상북도 경주시 양북면 일대에서 암컷 10마리와 수컷 5마리를 채집하였다. 동방자가사리의 염색체 수는 2n=42이었으며, 핵형은 30개의 중부염색체와 12개의 차중부염색체로 구성되어 있었다. FN 값은 84였으며, 암수 간 성적이형과 배수체는 관찰되지 않았다. 동방자가사리는 퉁가리속의 자가사리, 섬진자가사리와 염색체 수는 같았으나 핵형에서 차이를 보였다. 이러한 핵형의 차이는 지리적 격리로 인한 로버트슨 전좌(Robertsonian rearrangement)와 관련 있는 것으로 생각된다.

• International Journal of Stem Cells
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• 제17권1호
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• pp.1-14
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• 2024

The clustered regularly interspaced short palindromic repeats (CRISPR) system, a rapidly advancing genome editing technology, allows DNA alterations into the genome of organisms. Gene editing using the CRISPR system enables more precise and diverse editing, such as single nucleotide conversion, precise knock-in of target sequences or genes, chromosomal rearrangement, or gene disruption by simple cutting. Moreover, CRISPR systems comprising transcriptional activators/repressors can be used for epigenetic regulation without DNA damage. Stem cell DNA engineering based on gene editing tools has enormous potential to provide clues regarding the pathogenesis of diseases and to study the mechanisms and treatments of incurable diseases. Here, we review the latest trends in stem cell research using various CRISPR/Cas technologies and discuss their future prospects in treating various diseases.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5391-5397
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• 2012

Background: Neuroblastoma (NB), like most human cancers, is characterized by genomic instability, manifested at the chromosomal level as allelic gain, loss or rearrangement. Genetics methods, as well as conventional and molecular cytogenetics may provide valuable clues for the identification of target loci and successful search for major genes in neuroblastoma. We aimed to investigate AURKA and MYCN gene rearrangements and the chromosomal aberrations (CAs) to determine the prognosis of neuroblastoma. Methods: We performed cytogenetic analysis by G-banding in 25 cases [11 girls (44%) and 14 boys (66%)] and in 25 controls. Fluorescence in situ hybridization (FISH) with AURKA and MYCN gene probes was also used on interphase nuclei to screen for alterations. Results: Some 18.4% of patient cells exhibited CAs., with a significant difference between patient and control groups in the frequencies (P<0.0001). Some 72% of the cells had structural aberrations, and only 28% had numerical chnages in patients. Structural aberrations consisted of deletions, translocations, breaks and fragility in various chromosomes, 84% and 52% of the patients having deletions and translocations, respectively. Among these expressed CAs, there was a higher frequency at 1q21, 1q32, 2q21, 2q31, 2p24, 4q31, 9q11, 9q22, 13q14, 14q11.2, 14q24, and 15q22 in patients. 32% of the patients had chromosome breaks, most frequently in chromosomes 1, 2, 3, 4, 5, 8, 9, 11, 12, 19 and X. The number of cells with breaks and the genomic damage frequencies were higher in patients (p<0.001). Aneuploidies in chromosomes X, 22, 3, 17 and 18 were most frequently observed. Numerical chromosome abnormalities were distinctive in 10.7% of sex chromosomes. Fragile sites were observed in 16% of our patients. Conclusion: Our data confirmed that there is a close correlation between amplification of the two genes, amplification of MYCN possibly contributing significantly to the oncogenic properties of AURKA. The high frequencies of chromosomal aberrations and amplifications of AURKA and MYCN genes indicate prognostic value in children with neuroblastomas and may point to contributing factors in their development.

• 대한미생물학회지
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• 제34권6호
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• pp.519-532
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• 1999

Helicobacter pylori is a causative agent of type B gastritis and plays a central role in the pathogenesis of gastroduodenal ulcer and gastric cancer. To elucidate the host-parasite relationship of the H. pylori infection on the basis of molecular biology, we tried to evaluate the genomic diversity of H. pylori. An ordered overlapping bacterial artificial chromosome (BAC) library of a Korean isolate, H. pylori 51 was constructed to set up a genomic map. A circular physical map was constructed by aligning ApaI, NotI and SfiI-digested chromosomal DNA. When the physical map of H. pylori 51 was compared to that of unrelated strain, H. pylori 26695, completely different restriction patterns were shown. Fifteen known genes were mapped on the chromosome of H. pylori 51 and the genetic map was compared with those of strain 26695 and J99, of which the entire genomic sequences were reported. There were some variability in the gene location as well as gene order among three strains. For further analysis on the genomic diversity of H. pylori, when comparing the genomic structure of 150 H. pylori Korean isolates with one another, genomic macrodiversity of H. pylori was characterized by several features: whether or not susceptible to restriction digestion of the chromsome, variation in chromosomal restriction fingerprint and/or high frequency of gene rearrangement. We also examined the extent of allelic variation in nucleotide or deduced amino acid sequences at the individual gene level. fucT, cagA and vacA were confirmed to carry regions of high variation in nucleotide sequence among strains. The plasticity zone and strain-specific genes of H. pylori 51 were analyzed and compared with the former two genomic sequences. It should be noted that the H. pylori 51-specific sequences were dispersed on the chromosome, not congregated in the plasticity zone unlike J99- or 26695-specific genes, suggesting the high frequency of gene rearrangement in H. pylori genome. The genome of H. pylori 51 shows differences in the overall genomic organization, gene order, and even in the nucleotide sequences among the H. pylori strains, which are far greater than the differences reported on the genomic diversity of H. pylori.

• Journal of Genetic Medicine
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• 제7권2호
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• pp.156-159
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• 2010

염색체의 역위는 균형재배열을 나타내는 구조적 이상 중 하나로 대부분 정상표현형을 나타낸다. 그러나 생식 세포의 감수 분열 단계에서 역위 고리를 만들어 염색체의 결실 또는 중복을 보이는 재조합 염색체가 형성되면 자녀에게 비정상 표현형이 나타나게 된다. 본 증례는 균형전좌를 가진 산모와 그 태아에 대한 정확한 핵형분석을 위해 세포유전학적인 방법과 분자유전학적인 방법을 함께 이용한 증례 보고이다. Trypsin과 Giemsa를 이용한 GTG 분염법의 결과에서 태아는 산모와는 다른 형태의 구조적 이상이 나타났으며, 정확한 분석을 위해 MLPA와 FISH를 시행하였다. 그 결과역위를 보인 9번 염색체 단완 말단 부위의 부분 소실과 13번 염색체에서는 장완 말단 부위의 부분 증폭이 확인되었다. 이는 생식세포의 감수분열시 상동염색체 사이의 교차에 의한 결과로써 드문 재조합 염색체로 판단된다. 따라서 이 태아의 최종 염색체 분석 결과는 46,XY,rec(9)t(9;13)(p22;q32)inv(9)(p12q13)mat로 보고 하였다. 세포유전학적인 방법을 기초로 한 FISH 또는 MLPA 등과 같은 분자유전학적 방법의 적극적인 이용은 복잡한 염색체 이상을 보이는 핵형 분석에 있어서 유용하고 효과적인 방법이라 하겠다.

• Journal of Genetic Medicine
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• 제19권1호
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• pp.14-21
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• 2022

Complex chromosome rearrangements (CCRs) are structural chromosomal rearrangements involving at least three chromosomes and more than two breakpoints. CCR carriers are generally phenotypically normal but related to higher risk of recurrent miscarriage and having abnormal offspring with congenital anomalies. However, most of CCR carriers are not aware of their condition until genetic analysis of either abortus or affected baby or parental karyotyping is performed. Herein, we present the case that CCR carrier patients can be identified by preimplantation genetic testing of preimplantation embryos. An infertile male patient with severe oligoasthenoteratozoospermia was diagnosed balanced reciprocal translocation, 46,XY,t(3;11) (p26;p14) at first. After attempting the first preimplantation genetic testing for structural rearrangement (PGT-SR) cycle, we found the recurrent segmental gain or loss on 21q21.3-q22.3 of five out of nine embryos. As a result of karyotype re-analysis, the patient's karyotype showed a balanced CCR involving chromosomes 3, 11, and 21 with three breakpoints 3p26, 11p14, and 21q21. The patient underwent two PGT-SR cycles, and a pregnancy was established after the transfer of an euploid embryo in the second cycle. Amniocentesis confirmed that the baby carried normal karyotype without mosaicism. At 37 weeks gestation, a healthy girl weighting 3,050 g was born.