• BMB Reports
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• v.33 no.2
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• pp.138-146
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• 2000

In eukaryotes, chromosomes undergo a series of complex and coordinated movements during cell division. The kinesin motor proteins, such as the chicken Chromokinesin, are known to bind DNA and transport chromosomes on spindle microtubles. We previously cloned a family of retrograde C-terminus kinesins in Caenorhabditis elegans that mediate chromosomal movement during embryonic development. Here we report the cloning of a C. elegans klp-12 cDNA, encoding an ortholog of chicken Chromokinesin and mouse KIF4. The KLP-12 protein contains 1609 amino acid and harbors two leucine zipper motifs. The insitu RNA hybridization in embryonic stages shows that the klp-12 gene is expressed during the entire embryonic development. The RNA interference assay reveals that, similar to the role of Chromokinesin, klp-12 functions in chromosome segregation. These results support the notion that during mitosis both types, the anterograde N-terminus kinesins such as KLP-12 and the retrograde C-terminus kinesins, such as KLP-3, KLP-15, KLP-16, and KLP-17, may coordinate chromosome assembly at the metaphase plate and chromosomal segregation towards the spindle poles in C. elegans.

• Molecules and Cells
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• v.45 no.11
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• pp.792-805
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• 2022

Repairing damaged DNA and removing all physical connections between sister chromosomes is important to ensure proper chromosomal segregation by contributing to chromosomal stability. Here, we show that the depletion of non-SMC condensin I complex subunit H (NCAPH) exacerbates chromosome segregation errors and cytokinesis failure owing to sister-chromatid intertwinement, which is distinct from the ultra-fine DNA bridges induced by DNA inter-strand crosslinks (DNA-ICLs). Importantly, we identified an interaction between NCAPH and GEN1 in the chromatin involving binding at the N-terminus of NCAPH. DNA-ICL activation, using ICL-inducing agents, increased the expression and interaction between NCAPH and GEN1 in the soluble nuclear and chromatin, indicating that the NCAPH-GEN1 interaction participates in repairing DNA damage. Moreover, NCAPH stabilizes GEN1 within chromatin at the G2/M-phase and is associated with DNA-ICL-induced damage repair. Therefore, NCAPH resolves DNA-ICL-induced ultra-fine DNA bridges by stabilizing GEN1 and ensures proper chromosome separation and chromosome structural stability.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.213-217
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• 2022

Haploidization in somatic cells is the process of reducing the diploid somatic chromosomes to haploid. Several studies have attempted somatic haploidization using oocytes in mice and humans. Some researchers showed partial somatic haploidization, but none observed embryo development. Our study attempted somatic haploidization using the modified somatic nuclear transfer (SCNT) protocol with various combinations of chemicals or proteins in mice. This study induced the proper segregation of somatic homologous chromosomes and full embryo development in vitro. Furthermore, somatic haploid embryos established embryonic stem cells and produced live births. The current review summarizes this recent study on the success of somatic haploidization and provides an overview of other related studies on somatic haploidization.

• BMB Reports
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• v.47 no.6
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• pp.299-310
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• 2014

Cohesin is a multi-protein complex composed of four core subunits (SMC1A, SMC3, RAD21, and either STAG1 or STAG2) that is responsible for the cohesion of sister chromatids following DNA replication until its cleavage during mitosis thereby enabling faithful segregation of sister chromatids into two daughter cells. Recent cancer genomics analyses have discovered a high frequency of somatic mutations in the genes encoding the core cohesin subunits as well as cohesin regulatory factors (e.g. NIPBL, PDS5B, ESPL1) in a select subset of human tumors including glioblastoma, Ewing sarcoma, urothelial carcinoma, acute myeloid leukemia, and acute megakaryoblastic leukemia. Herein we review these studies including discussion of the functional significance of cohesin inactivation in tumorigenesis and potential therapeutic mechanisms to selectively target cancers harboring cohesin mutations.

• Journal of Microbiology and Biotechnology
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• v.2 no.1
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• pp.46-49
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• 1992

The availability of Phaffia rhodozyma as an astaxanthin sources in the aquaculture industry is limited because of the low carotenoid content of natural isolate. In this study, we have used the protoplast fusion technique to construct cell hybrids with an increased content of astaxanthin from P. rhodozyma. Cell hybrids (F307 and F406) obtained were very stable and produced considerably more astaxanthin (> 1 mg/g yeast) than the wild parent. Karyogamy was confirmed by the isolation of recombinants after mitotic segregation of parental auxotrophic genetic markers, the increased amount of chromosomal DNA/cell and the presence of single nucleus/cell.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.70-73
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• 1999

This study was conducted to ascertain the chromosomal locations and effect of quantitative trait loci (QTL) associated with the physical traits of rice (Oryza sativa L.) eating quality. One hundred sixty four recombinant inbred lines (MGRILs) of F$_{11}$ were derived from the cross between Milyang 23 (Tongil type) and Gihobyeo (japonica type). They were evaluated for six physical traits of cooked rice. Transgressive segregation was observed for all examined traits. Significant QTL were detected (LOD$\geq$2.0) in three traits, including single QTL for adhesiveness, gumminess, and chewiness of cooked rice, respectively. Phenotypic variation explained by each QTL ranged from 6.3% to 14.6%. However, no significant QTL was detected for hardness, cohesiveness, and elasticity of cooked rice. Pleiotropic effects of single QTL on different traits are observed.d.

• Animal Systematics, Evolution and Diversity
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• v.4 no.2
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• pp.91-102
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• 1988

Both Cobitis lutheri Rendahl and C.striata Ikeda previously regarded as the subspecies of C.taenia are revised here and raised to the species rank based on the distinct color pattern on their body sides in relation to the shpae of lamina circularis and suborbital spine, and distinct distributional patter. C. lutheri was similar to C. striata in chromosome number and karyotype, but chromosomal polymorphism as Robert sonian event was confirmed only in the population of C.lutheri studies. Both, C. kutheri and C..striata have disjunct ranges : the former in western Korea and east-northern China Mainland, the latter in the Smjin River of korea and west-southern Japan. hybridization between C. lutheri and C. striata by secondary contact appeared in the limited zone of the Dongjin River, Chllabuk-do province, korea, but the evidence for habitat segregation between them suggests the possibility that natural hybridization occurs between the two species and introgression results. We consider that the two species were produced as ecological equivalent species in the different branch stream of the Paleo-Hwangho River , The time of recession of sea level during the gracial period.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3669-3676
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• 2013

Faithful transmission of genetic information depends on accurate chromosome segregation as cells exit from mitosis, and errors in chromosomal segregation are catastrophic and may lead to aneuploidy which is the hallmark of cancer. In eukaryotes, an elaborate molecular control system ensures proper orchestration of events at mitotic exit. Phosphorylation of specific tyrosyl residues is a major control mechanism for cellular proliferation and the activities of protein tyrosine kinases and phosphatases must be integrated. Although mitotic kinases are well characterized, phosphatases involved in mitosis remain largely elusive. Here we identify a novel variant of mouse protein tyrosine phosphatase containing domain 1 (Ptpcd1), that we named Ptpcd2. Ptpcd1 is a Cdc14 related centrosomal phosphatase. Our newly identified Ptpcd2 shared a significant homology to yeast Cdc14p (34.1%) and other Cdc14 family of phosphatases. By subcellular fractionation Ptpcd2 was found to be enriched in the cytoplasm and nuclear pellets with catalytic phosphatase activity. By means of immunofluorescence, Ptpcd2 was spatiotemporally regulated in a cell cycle dependent manner with cytoplasmic abundance during mitosis, followed by nuclear localization during interphase. Overexpression of Ptpcd2 induced mitotic exit with decreased levels of some mitotic markers. Moreover, Ptpcd2 failed to colocalize with the centrosomal marker ${\gamma}$-tubulin, suggesting it as a non-centrosomal protein. Taken together, Ptpcd2 phosphatase appears a non-centrosomal variant of Ptpcd1 with probable mitotic functions. The identification of this new phosphatase suggests the existence of an interacting phosphatase network that controls mammalian mitosis and provides new drug targets for anticancer modalities.

• Molecules and Cells
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• v.21 no.3
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• pp.360-366
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• 2006

Up to 35% of the rice genome consists of various kinds of transposons, and CACTA and MITE are two of the major class 2 DNA transposons in the genome. We have employed the consensus sequences of Rim2/Hipa CACTA, Stowaway MITE Pangrangja, and Tourist MITE Ditto for transposon display (TD) analysis to locate them on a genetic map, with 58 SSR markers used to anchor them. The TD analysis produced a high profile of the polymorphisms between the parental lines, Oryza sativa var. Gihobyeo/O. sativa var. Milyang, in intraspecific $F_{15}$ RIL lines, locating 368 markers of Rim2/Hipa CACTA, 78 markers of Tourist MITE Ditto, and 22 markers of Stowaway MITE Pangrangja. In the segregation analysis, non-parental segregating bands and segregation distortion bands were observed. The recombinant genetic map spans 3023.9 cM, with 5.7 cM the average distance between markers. The TD markers were distributed unequally on the chromosomes because many TD markers were located in pericentric chromosomal regions except in the cases of chromosomes 2, 3, 6 and 9. Although the number of transposon markers was not sufficient to include all rice class 2 transposons, the current map of CACTA and MITE transposons should provide new insight into the genome organization of rice since no previous DNA transposon map is available.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.199-204
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• 1998

This study was conducted to investigate the chromosomal locations and effects of quantitative trait loci (QTL) associated with chemical properties of rice (Oryza sativa L.). One hundred sixty four recombinant inbred lines (MGRILs) of $F_{11}$ were derived from the cross between Milyang 23, Tongil type, and Gihobyeo, japonica type. They were evaluated for 7 traits of chemical property in rice. Transgressive segregation was observed for all traits examined. Eight significant QTLs were detected (LOD$\geq$2.0) for five traits, including two QTLs for amylose content, two QTLs for potassium content, one QTL for ratio of magnesium to potassium, one QTL for fat content and two QTLs for ash content. Phenotypic variation explained by each QTL ranged from 7.2% to 14.4%. However, no significant QTL was detected for magnesium and protein contents. In amylose content and ash content M alleles originated from Milyang 23 were responsible for increasing these traits and J alleles originated from Gihobyeo also responsible for increasing these traits. Pleiotropic effects of single QTLs on different traits are observed.