• Animal cells and systems
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• v.4 no.2
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• pp.105-107
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• 2000

Cytogenetic features of three ascidian species were studied with specimens obtained from Korean coastal areas. The gonadal tissue was processed in order to obtain mitotic and meiotic chromosomes. The chromosome numbers of Amaroucium pliciferum turned out to be 2n=26 and n=l3 with 2sm, 3st, 8t and Halocynthia roretzi to be 2n=16 and n=8 with 6m, 2t. Diploid number of chromosomes in Dendrodoa aggregata was 64 with 32t. The karyotypes of these Korean ascidians were reported for the first time.

• Animal cells and systems
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• v.8 no.2
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• pp.105-109
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• 2004

Aminoalcoholphosphotransferase catalyzes the synthesis of phosphatidylcholine and phosphatidylethanolamine from diacylglycerol plus a CDP-aminoalcohol such as CDP-choline or CDP-ethanolamine. Previously we suggested the presence of possible isoforms of this enzyme from Chinese cabbage roots and now report the cDNA cloning and expression analysis of AAPT3 encoding a third isoform of aminoalcoholphosphotransferase (AAPT3). AAPT3 contains an open reading frame of 1,176 bp coding for a protein of 392 amino acids. It shares 96 and 95% identity with Chinese cabbage AAPT1 and AAPT2, respectively, at the deduced amino acid level. The results from reverse transcriptase-polymerase chain reaction analysis indicate that expression of AAPT3 is up-regulated by low temperature as well as AAPT1 and AAPT2.

• Animal cells and systems
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• v.2 no.3
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• pp.297-302
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• 1998

A taxonomic study was made on the genus Tremex (Hymenoptera: Siricidae) in Korea. The study was carried out with specimens collected throughout the country from 1996 to 1998 and preserved in museums and laboratories of Universities in Korea and in other countries. As a result of this study, the genus Tremex found in Korea now consists of 5 species including one newly recorded species, Tremex contractus Maa and one new species, Tremex nigrocephalus n. sp.

• Animal cells and systems
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• v.4 no.1
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• pp.45-50
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• 2000

We found a brown frog species, which is unrecorded from South Korea. Rana huanrenensis Fei, Ye, and Huang (1990), This species was originally described from northeastern China. In having 2n=24 chromosomes, this species is closely related to Rana dybowskii, R. chensinensis, R. ornativentris, R. pirica, and Chinese R. huanrenensis, but it is different from the first four species in the ecological, morphological, and genetic characteristics. By contrast, this species Is identical to Chinese R. huanrenensis In the habitat of montane stream-breeding, absence of the vocal sac, and genetic properties. This record is a significant range extention of R. huanrenensis.

• Animal cells and systems
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• v.9 no.4
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• pp.211-213
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• 2005

In bird species that suffer brood parasitism, the question about which sex is responsible for egg rejection has important implications for determining the coevolutionary relationship between brood parasites and their hosts. In order to determine which sex rejects a parasitic egg in vinous-throated parrotbills (Paradoxornis webbianus) which have egg color dimorphism, we conducted model egg experiments and video-recorded the behavior of the focal pair. Both sexes showed rejection behavior to the parasitic eggs. It indicates that the vinous-throated parrotbill may have a high rejection rate and faster spread of any rejection alleles through out populations. However, further studies are still needed to confirm the egg recognition mechanism in this species, which will expand our knowledge of the evolutionary relationship between host and parasite.

• Animal cells and systems
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• v.3 no.1
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• pp.69-72
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• 1999

A tandemly repeated DNA sequence was identified and characterized y the combined RAPD and FISH data from a total genomic DNA of Welsh onion (Allium fistulosum). A clone containing this repeating sequence was selected and sequenced. This repeating unit of 314 bp inserted into pAf 072 contained 54.1% adenine and thymine residues, and showed the primer sequence used, 5'-GAAACGGGTG-3', in both terminals of the sequence. Fluorescence in situ hybridization using this tandemly repeated sequence as a probe indicated that the detected sites were coincident with the major C-banded constitutive heterochromatin in the terminal regions of both arms of all 6 chromosomes.

• Animal cells and systems
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• v.5 no.2
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• pp.91-99
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• 2001

Vertebrates regenerate tissues in three ways: proliferation of cells that maintain some or all of their differentiated structure and function, redifferentiation of mature cells followed by proliferation and redifferentiation into the same cell type or transdetermination to another cell type, and activation of restricted lineage stem cells, which have the ability to transdetermine to different lineages under the appropriate conditions. The behavior of the cells during regeneration is regulated by growth factors and extracellular matrix molecules. Some non-regenerating tissues are now known to harbor stem cells which, though they form scar tissue in vivo, are capable of producing new tissue-specific cells in vitro, suggesting that the injury environment inhibits latent regenerative capacity. Regenerative medicine seeks to restore tissues via transplantation of stem cell derivatives, implantation of bioartificial tissues, or stimulation of regeneration in vivo. These approaches have been partly successful, but several research issues must be addressed before regenerative medicine becomes a clinical reality.

• The Korean Journal of Mycology
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• v.51 no.1
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• pp.57-62
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• 2023

In Korea, Cornus controversa and C. florida are known as hosts of Erysiphe pulchra from section Microspharea of the genus Erysiphe. However, recent molecular-phylogenetic analyses on the internal transcribed spacer regions and large subunit gene of the rDNA revealed that the Erysiphe powdery mildew on C. controversa in Japan is in fact E. cornicola. To assess the taxonomic status of Erysiphe-C. controversa association in Korea, isolates collected since 1987 were investigated and consequently identified as E. cornicola based on molecular-phylogenetic analyses and new morphological traits. To our knowledge, this is the first study to confirm the presence of this powdery mildew in Korea.

• Animal cells and systems
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• v.1 no.2
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• pp.247-257
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• 1997

Genetic and morphological variations of Korean Hynobius leechii were surveyed. Starch gel electrophoresis was used to study genetic variation at 23 loci. H. leechii is genetically divided into three groups, each of which is named as Form-A, Form-B, and Form-C. These forms are clearly separated with 4-5 fixed or nearly fixed allelic differences. At a sympatry near Jangseong, Jollanam-do, a significant deviation from random mating between Form-A and Form-B was observed. Therefore, they are considered as two distinct taxi of specific rank. Form-A is widely distributed in the inland of Korea, whereas Form-B is distributed in the islands or near the coastal regions of Western and Southern Korea. Form-B had, in addition, a significant morphological difference from Form-A. On the other hand, Form-C was restricted to an area near Kori atomic power plant, Kyongsangnam-do, and the genetic similarities between this form and Form-A and Form-B were 0.742 and 0.736, respectively. Moreover, Form-C had a unique color pattern, short body and small coccyx. Thus, it seems reasonable to assign this form as another new species.

• Animal cells and systems
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• v.3 no.2
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• pp.161-165
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• 1999

Nephila clavata, a golden orb-web spider, was studied at two different field sites with respect to web size, height, and orientation. A majority of spiders at Site 1 (a band of shrub bush) built their webs parallel or nearly parallel to the edge of the bush. Similarly, at Site 2 (near a pond), most webs were aligned with the shoreline of the pond. Among the possible determining factors for the observed patterns of web orientation, wind and light did not appear important. Instead, the movement direction of insect prey appeared largely responsible. Disproportionately more webs faced outside the bush and toward the pond than inside the bush and away from the pond at Site 1 and 2, respectively. Such trend was more apparent for larger spiders with larger webs.