• Journal of Sericultural and Entomological Science
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• v.43 no.1
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• pp.53-54
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• 2001

The chromosome number of Morus bombycis Koidz. and Morus monogolica C.K.Schn. growing wild in the Korea Peninsula is diploid (2n=28) and that of Morus tiliaefolia Makino is hecxaploid (2n=84). The somatic cell division of each species is nomal.

• Journal of Sericultural and Entomological Science
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• v.3
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• pp.59-60
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• 1963

It was prved by the author that : 1. The Smear Method with the buds of mulberry just before sprouting, can be used as one of the best methods in observation of the chromosome number. 2. The chromosome number of the Korean native mulberry is 28 in all (2n=28). 3. Triploid in mulberry can never occur under natural weather condition.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.25-25
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• 2019

Chromosome numbers and karyotypes in flowering plants have been considered to be prominent features in taxonomic and evolutionary context. Despite the increasing numbers of cytological studies in Asteraceae, karyotype analysis of Cirsium Mill. and Carddus L. in Korean population have not been performed carefully. In this study, the chromosome numbers and karyotype analysis of all eight species of the genus Cirsium Mill. and one species of Carddus L. were analyzed. While the chromosome number in Carduus crispus L. was diploid (2n = 2x = 18 or 18+2Bs) with x = 9 as the base chromosome number, all seven species of Cirsium were diploid with x = 17 except for Cirsium lineare (Thunb.) Sch. Bip. (x = 14). The chromosome number in C. pendulum Fisch. ex DC. presented 2n = 2x = 34 from two populations and C. lineare exhibited 2n = 2x = 28 from one population. Aneuploidy was occasionally found in C. japonicum Fisch. ex DC. var. spinossinum Kitam. (2n = 2x = 34, 35, 36), C. rhinoceros (H. $L{\acute{e}}v.$ & Vaniot) Nakai (2n = 2x = 32, 34), C. setidens (Dunn) Nakai (2n = 2x = 30, 31, 32) and C. vlassovianum Fisch. ex DC. (2n = 2x = 31, 32). While Cirsium japonicum Fisch. ex DC. var. japonicum possessed several B-chromosomes (2n = 2x = 34, 35, 36), polyploidy was only encountered in Cirsium nipponicum (Maxim.) Makino. (2n = 4x = 68) from two populations in Ulleung Island. The present cytological data might be contributed to the taxonomic and evolutionary studies in the genus Cirsium.

• Korean Journal of Plant Taxonomy
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• v.52 no.2
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• pp.102-107
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• 2022

Rhododendron keiskei var. hypoglaucum (Ericaceae) was recently reported in Korea, with a disjunct distribution on the southern islands of the Korean Peninsula. Although chromosome numbers and ploidy variations are important traits in angiosperms, gaining a clear understanding the cytological features of Rhododendron has been hampered by the small size of its chromosomes. We herein report the chromosome number, karyotype structure, and genome size of R. keiskei var. hypoglaucum for the first time. The chromosome number of the investigated plants was 2n = 26 with x = 13 as the base chromosome number, which is the one of the frequently encountered base chromosome numbers in Rhododendron. The karyotype of R. keiskei var. hypoglaucum is composed of metacentric and submetacentric chromosomes similar in length, which ranged from 1.39 to 2.40 ㎛. The DNA 1C-value in all examined accessions was small, ranging from 0.63 to 0.65 pg, further supporting the stable genome size in Rhododendron. These comprehensive cytological results provide a framework for detailed molecular, cytogenetic, and phylogenomic analyses that can be used to interpret the slow species diversification rate in Rhododendron.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.172-176
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• 1999

Chromosome of cobitid fishes, Iksookimia yongdokensis collected from the 4 streams flowing to the eastsouthern coast of Korea was studied using chromosome of gill and kidney cells prepared by flame drying technique. The results obtained were as follows: the chromosome number was 100 composed of 44 meta-submetacentric and 56 subtelo-telocentric chromosomes, and the fundamental number (FN) was 144. It was remarked that Iksookimia yongdogensis was distinguishable from its congeners in the karyotype. The above evidences may suggest that Iksookimia yongdokensis was one of the tetraploid species of cobitid fishes.

• Journal of Life Science
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• v.20 no.5
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• pp.789-793
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• 2010

Artificial chromosome manipulation and amplification of single-copy yeast artificial chromosome (YAC) are usually required in order to use YACs for applications such as physical mapping and functional analysis in eukaryotes. We designed and implemented a Simultaneous YAC Manipulation-Amplification (SYMA) system that combines the copy number amplification system of YAC with a convenient YAC manipulation system. To achieve the desired split and to amplify a YAC clone-harboring plant chromosome, a pBGTK plasmid containing a conditional centromere and thymidine kinase (TK) gene was constructed as a template to amplify the splitting fragment via PCR. By splitting, new 490-kb and 100-kb split YACs containing the elements for copy number amplification were simultaneously generated from a 590-kb YAC clone. The 100-kb split YAC was then successfully amplified 14.4-fold by adding 3 mg/ml sulfanilamide and $50\;{\mu}g/ml$ methotrexate (S3/M50) as inducing substances.

• Journal of the Korea Society for Simulation
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• v.26 no.4
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• pp.1-9
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• 2017

The Genetic Algorithm(GA) is a global search algorithm based on biological genetics. It is widely used in various fields such as industrial applications, artificial neural networks, web applications and defense industry. However, conventional Genetic Algorithm has difficulty maintaining feasibility in complicated situations due to its fixed number of chromosomes. This study proposes the Genetic Algorithm using variable chromosome with chromosome attachment. And in order to verify the implication of changing number of chromosomes in the simulation, it applies the Genetic Algorithm using variable chromosome with chromosome attachment to antisubmarine High Value Unit(HVU) escort mission simulation. As a result, the Genetic Algorithm using variable chromosome has produced complex strategies faster than the conventional method, indicating the increase of the number of chromosome during the process.

• Parasites, Hosts and Diseases
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• v.41 no.1
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• pp.41-45
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• 2003

Effects of gamma irradiation on the worm survival and chromosomal aberration of Clonorchis sinensis were studied. The metacercariae irradiated with various amounts of gamma radiation (ranging from 5 Gy to 50 Gy) were fed to rats, and the effects were compared with those of non-irradiated controls. Recovery rates of adult worms in irradiated groups were reduced gradually as increasing of the irradiation doses. No worm was recovered from rats which were fed with 50 Gy irradiated metacercariae. The chromosome number was 2n = 56 in all worms from all experimental groups. However, the groups irradiated with 20 Gy, 25 Gy or 30 Gy showed variations in the chromosome number, depending on different cells in the same individual. Radiation doses used in this study did not appear to induce chromosome aberrations, however, irradiation with 30 Gy showed slightly reduced chromosome size.

• Korean Journal of Poultry Science
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• v.13 no.2
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• pp.167-172
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• 1986

Chromosome size, number and shape were studied by the centromeric index, the arm ratio and the relative length of chromosome. The chromosomes of 50 early chick embryos which were derived from a pure line of Single Comb White Leghorns were examined. Using a colchicine, hypotonic treatment, fixation and air-drying technique, the clear prometaphase figures were obtained from the whole embryo. The results of the present investigation of chromosome pairs were as follows, 1. Pair 1 and 2; metacentric and submetacentric chromosomes which could be clearly distinguished from each other by size. 2. Pair 3 and 4: acrocentric chromosomes of similar length but the 4th pair had a distinct short arm which was not present in the 3rd. 3, Pair 5; metacentric sex chromosomes, 2 chromosome had relative 5th length but the W chromosome had slightly shorter length than 7th pair of chromosomes. 4. Pair 6; acrocentric chromosomes similar in shape to pair 3 but of little more than half the size. 5, Pair 7 and 8; acrocentric chrocentric but the 7th pairs had a definite short arm. 6. Pair 9; similar length to the 7, 8 pairs but had a medially placed centromere. 7. microchromosomes of 30 pairs ; nearly all acrocentric chromosomes which appeared as paired dots. The total number of diploid was appeared to 72-78. But a number of observations presented the total diploid number in 78 (58%). The inconstancy in number observed in this study was presumably due to the minute size of the microchromosomes. Thus, the modal numbers for the diploid chromosome was at least 78.

• The Korean Journal of Zoology
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• v.33 no.2
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• pp.222-230
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• 1990

The karyotypes of Korean Sciunis vulgaris coreas and Tamias sibiricus asiaticus were analyzed by conventional Giemsa staining and C-banding method. The diploid chromosome number (2n) of Sciunis vulgaris coreae 40 consisting of 6 metacentric, 8 submetacentric, 3 subtelocentric and 2 telocentric autosome pairs, submetacentric X and acrocentric or subtelocentric Y chromosome. The arm number (NF) of this species was obtained as 72, excluding the gonosomal arms. Tamias sibiricus asiaticus has a 2n of 38. The karyotype was represented by 3 metacentric, 4 submetacentric, 5 subtelocentric and 6 telocentric autosome paits and 2 sex chromosome. The X chromosome was submetacentric chromosome and the Y was the smallest chromosome with a median. The NF was 60. In S. vulgaris coreae constitutive heterochromatins were observed at the centromeres and telomeres. Constitutive heterochnomatins of T sibiricus asiaticus were primarily observed at the centromeres. These results suggested that non-Robensonian reanagenents and distribution of constitutive heterochromatin played an imporiant role in karyological differentiation of these species.