• Korean Journal of Medicinal Crop Science
• /
• v.11 no.5
• /
• pp.402-407
• /
• 2003

Karyotype analysis and chromosomal localization of 5S and 45S rDNAs using multi-color fluorescence in situ hybridization (McFISH) technique were carried out in Bupleurum longeradiatum. Somatic metaphase chromosome number was 2n=12. Karyotype was composed of three pairs of metacentrics (No.3, 4 and 6) and three pairs of submetacentrics (No. 1, 2 and 5). The length of somatic prometaphase chromosomes ranges from 2.55 to $5.05{\mu}m$ with total length of $18.15\;{\mu}m$. In FISH experiment, one pair of 5S rDNA signals was detected on the pericentromeric region of chromosome 4 and one pair of 45S rDNA signals was detected on the telomeric region of chromosome 2.

• Journal of Life Science
• /
• v.17 no.6 s.86
• /
• pp.762-765
• /
• 2007

A Giemsa C-banding method was used for the identification of somatic chromosomes and heterochromatic knob position in Korean indigenous waxy com (Zea mays L.). 5 inbred stocks were examined and their heterochromatic knob numbers ranged from 6 to 12. In comparison of homologous chromosomes of two stocks of YS-1 and MY-1, knob numbers, knob positions, arm ratios and relative length of chromosomes were different between the genotypes. The length of homologous chromosomes in YS-1 were generally larger than those of MY-1. The Giemsa method was proved to be useful for the identification of somatic chromosome and a C-banded diagram showing knob positions, arm ratios and relative length of chromosome could be used as a good tool to compare the characteristics of chromosomes of Korean indigenous waxy corn stocks.

• Korean Journal of Plant Taxonomy
• /
• v.43 no.2
• /
• pp.139-145
• /
• 2013

This study was carried out to determine the karyotype and chromosomal localizations of 45S and 5S rDNAs using FISH in Astragalus koraiensis. The somatic metaphase chromosome number of this species was 2n = 16 with basic chromosome number of x = 8. The karyotype of A. koraiensis was consisted of six pairs of median region chromosomes(chromosome 1, 3, 4, 5, 6, 8) and two pairs of submedian chromosomes(chromosome 2, 7). Based on the FISH, one pair of 45S rDNA site was detected on the centromeric region of chromosome 5. Whereas, two pair of 5S sites were detected on the short arm of chromosome 4 and centromeric region of chromosome 7, respectively. These are quite different patterns from A. membranaceus, A. membranaceus var. alpinus, and A. mongholicus. Although A. koraiensis is considered as Korean endemic species, therefore, it should be conducted out comparative FISH study with A. sikokianus and A. bhotanensis which are very similar to A. koraiensis morphologically.

• Korean Journal of Plant Taxonomy
• /
• v.35 no.2
• /
• pp.129-142
• /
• 2005

Somatic chromosome numbers of 19 taxa of Korean Rubus was investigated. Subg. Anoplobatus (2 species), subg. Cylactis (1 species), subg. Idaeobatus (15 taxa) and subg. Malachobatus (1 species) are found in Korea. All taxa belonging to subg. Idaeobatus except for R. parvifolius which shows tetrapolid and hexaploid are diploid. The basic chromosome number of the genus was x=7. New chromosome numbers for 5 taxa were reported here: R. hongnoensis of Jeju-island endemic species, 2n=14; R. longisepalus, 2n=14; R. longisepalus var. tozawai, 2n=14; R. parvifolius, 2n=28; R. parvifolius var. taquetii, 2n=28. The rest 12 taxa except for R. coreanus Miq was well counted as 2n=14 and well consistent with previous reports from China and Japan. Our new chromosome level for R. parvifolius as 6x may indicate that speciation by polyploidization has occurred within Korean population. Unlikely to Japanese population (2n=42), Korean population of R. buergeri has same ploidy level with Taiwanese population as 2n=56.

• Korean Journal of Plant Taxonomy
• /
• v.43 no.1
• /
• pp.22-26
• /
• 2013

We report somatic chromosome numbers 2n = 12 for three Carex sect. Siderostictae Franch. ex Ohwi (Cyperaceae) from Korean populations: Carex ciliatomarginata Nakai, C. okamotoi Ohwi, and C. siderosticta Hance. This study is the first chromosome number report for the species C. ciliatomarginata from Korean populations. As found in other Carex species, all the chromosomes examined in the section exhibit nonlocalized centromere (polycentric or holocentric) and large (more than ca. $1{\mu}m$ long) chromosomes. Considering the basal phylogenetic position of the section in tribe Cariceae Pax, small numbers of large chromosomes have been hypothesized as primitive characters in Cariceae, and our observation supports the hypothesis. Further investigations of chromosomes in Carex are needed for a better understanding of species richness in the genus.

• Korean Journal of Animal Reproduction
• /
• v.26 no.4
• /
• pp.385-394
• /
• 2002

This study was constructed the correlations of the embryonic developmental rates and the frequency of chromosome aberration using ear-skin-fibroblast cell in nuclear transfer (NT) derived embryos. Karyoplast-oocyte complexes were fused and activated simultaneously, then cultured for seven days to assess development. The developmental rates of NT and in vitro fertilization (IVF) embryos were 55.4% vs 63.5%, 31.7% vs 33% and 13.4% vs 16.8% in 2 cell, 8 cell and blastocyst, respectively. Firstly, the frequency of chromosome aberrations were evaluated using fluorescent in situ hybridization (FISH) technique with porcine chromosome 1 submetacentric specific probe. Chromosome aberration was detected at day 3 on the embryo culture, the percentages of chromosomal aneuploidy in NT and IVF embryos at 4-cell stage were 40%, 31.3%, respectively. Secondly, embryonic fragmentation was evaluated at 4-cell stage embryo. Frequency of embryonic fragmentations was in 51.3% of NT, 61.3% of IVF, 28.9% of parthenogenetic activation at 4-cell stage. The proportion of fragmentation in NT embryos was higher than activation embryos. This result indicates that chromosomal abnormalities and embryonic fragments are associated with low developmental rate in porcine NT embryo. It is also suggest that abnormal porcine embryos produced by NT related with lower implantation rate, increased abortion rate and production of abnormal fetuses.

• Korean Journal of Plant Resources
• /
• v.21 no.3
• /
• pp.226-229
• /
• 2008

We described and illustrated a rare species in Korea, Hypoxis aurea Lour. (Hypoxidaceae) which was rediscovered about 70 years after its first collection from Jeju island in Korea. The members of the family Hypoxidaceae R. Br. are distinguished from the plants of Amaryllidaceae J. St-Hill. by having grass-like leaves, an invisible stem which is modified into a corm or a rhizome, trimerous, and radially symmetric flowers with an inferior ovary developing into a capsule on scapes. Hypoxis aurea Lour. is readily distinguishable from Curculigo orchinoides Gsertn. in Japan by beakless ovary and capsular fruit. The number of somatic chromosome is 2n=54.

• BMB Reports
• /
• v.52 no.8
• /
• pp.482-489
• /
• 2019

Reproductive biotechnology has developed rapidly and is now able to overcome many birth difficulties due to infertility or the transmission of genetic diseases. Here we introduce the next generation of assisted reproductive technologies (ART), such as mitochondrial replacement technique (MRT) or genetic correction in eggs with micromanipulation. Further, we suggest that the transmission of genetic information from somatic cells to subsequent generations without gametes should be useful for people who suffer from infertility or genetic diseases. Pluripotent stem cells (PSCs) can be converted into germ cells such as sperm or oocytes in the laboratory. Notably, germ cells derived from nuclear transfer embryonic stem cells (NT-ESCs) or induced pluripotent stem cells (iPSCs) inherit the full parental genome. The most important issue in this technique is the generation of a haploid chromosome from diploid somatic cells. We hereby examine current science and limitations underpinning these important developments and provide recommendations for moving forward.

• BMB Reports
• /
• v.51 no.9
• /
• pp.437-443
• /
• 2018

Non-homologous end joining (NHEJ), and to a lesser extent, the error-free pathway known as homology-directed repair (HDR) are cellular mechanisms for recovery from double-strand DNA breaks (DSB) induced by RNA-guided programmable nuclease CRISPR/Cas. Since NHEJ is equivalent to using a duck tape to stick two pieces of metals together, the outcome of this repair mechanism is prone to error. Any out-of-frame mutations or premature stop codons resulting from NHEJ repair mechanism are extremely handy for loss-of-function studies. Substitution of a mutation on the genome with the correct exogenous repair DNA requires coordination via an error-free HDR, for targeted transgenesis. However, several practical limitations exist in harnessing the potential of HDR to replace a faulty mutation for therapeutic purposes in all cell types and more so in somatic cells. In germ cells after the DSB, copying occurs from the homologous chromosome, which increases the chances of incorporation of exogenous DNA with some degree of homology into the genome compared with somatic cells where copying from the identical sister chromatid is always preferred. This review summarizes several strategies that have been implemented to increase the frequency of HDR with a focus on somatic cells. It also highlights the limitations of this technology in gene therapy and suggests specific solutions to circumvent those barriers.

• Molecules and Cells
• /
• v.27 no.2
• /
• pp.205-209
• /
• 2009

The loci of the 5S and 45S rRNA genes were localized on chromosomes in five species of Capsicum, namely, annuum, chacoense, frutescens, baccatum, and chinense by FISH. The 5S rDNA was localized to the distal region of one chromosome in all species observed. The number of 45S rDNA loci varied among species; one in annuum, two in chacoense and frutescens, and chinense, and four in baccatum, with the exceptions that 'CM334' of annuum had three loci and 'tabasco' of frutescens gad one locus. 'CM334'-derived BAC clones, 384B09 and 365P05, were screened with 5S rDNA as a probe, and BACs 278M03 and 262A23 were screened with 25S rDNA as a probe. Both ends of these BAC clones were sequenced. FISH with these BAC probes on pachytenes from 'CM334' plant showed one 5S rDNA locus and three 45S rDNA loci, consistent with the patterns on the somatic chromosomes. The 5S rDNA probe was also applied on extended DNA fibers to reveal that its coverage measured as long as 0.439 Mb in the pepper genome. FISH techniques applied on somatic and meiotic chromosomes and fibers have been established for chili to provide valuable information about the copy number variation of 45S rDNA and the actual physical size of the 5S rDNA in chili.