• Title/Summary/Keyword: dimorphism

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Copepodid Stages of Ergasilus hypomesi Yamaguti(Copepoda, Poecilostomatoida, Ergasilidae) from a Brackish Lake in Korea

  • Kim, Il-Hoi
    • Animal cells and systems
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    • v.8 no.1
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    • pp.1-12
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    • 2004
  • All copepodid stages and free-swimming adults of Ergasilus hypomesi Yamaguti collected from plankton samples from a brackish lake in Korea are described. The antennule remains a four-segmented appendage until copepodid V. The antenna of copepodid I carries a vestigial exopod. Sexual dimorphism first appears at copepodid IVwhose males bear primodial maxillipeds. Leg 5 also is sexually dimorphic from copepodid IV onwards, with its free segment bearing three setae in the female and two setae in the male. Morphological features of some appendages appearing during copepodid development are discussed. It is noticed that the early copepodids of the Ergasilidae show the characteristic setation on the biramous legs and proximal segments of the antennule.

The Distributions of Three Genetic Polymorphisms in the Estrogen $Receptor-\alpha$ Gene in Korean Essential Hypertensives (한국인 본태성 고혈압군에서 에스트로젠 수용체-$\alpha$(유전자에 존재하는 다형성의 분포에 관한 연구)

  • Kim Ji Young;Kang Byung Yong;Lee Kang Oh
    • Environmental Analysis Health and Toxicology
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    • v.20 no.3 s.50
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    • pp.249-258
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    • 2005
  • Blood pressure, obesity and bone mineral density are multifactorial traits influenced by genetic factor. The purpose of this study was to clarify the association between three genetic polymorphisms in the estrogen receptor-$\alpha$ (ER -$\alpha$) gene and essential hypertension in korean population. One hundred and seventy-one people including 90 normotensives and 81 essential hypertentives were recruited. Among genetic polymorphisms studied, the Xba I RFLP in the intron 1 of this gene polymorphism was significantly associated with essential hypertension in women, suggesting the sexual dimorphism in genetic effect (P (<) 0.05). Further studied suggest that a larger sample size of this study are needed.

Resveratrol Impaired the Morphological Transition of Candida albicans Under Various Hyphae-Inducing Conditions

  • Okamoto-Shibayama, Kazuko;Sato, Yutaka;Azuma, Toshifumi
    • Journal of Microbiology and Biotechnology
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    • v.20 no.5
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    • pp.942-945
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    • 2010
  • The ability of the human fungal pathogen Candida albicans to undergo the morphological transition from a single yeast form to pseudohyphal and hyphal forms in response to various conditions is known to be important for its virulence. Many studies have shown the pharmacological effects of resveratrol, a phytoalexin polyphenolic compound. In this study, we investigated the antifungal activity of resveratrol against C. albicans. Both yeast-form and mycelial growth of C. albicans were inhibited by resveratrol. In addition, normal filamentation of C. albicans was affected and yeast-to-hypha transition under serum-, pH-, and nutrient-induced hyphal growth conditions was impaired by resveratrol.

Morphological Differences of Immature Stages between Males and Females in a Korean Wood-Feeding Cockroach (Cryptocercus kyebangensis)

  • Park, Yung-Chul;Choe, Jae-Chun
    • Animal cells and systems
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    • v.7 no.2
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    • pp.105-109
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    • 2003
  • Morphological characteristics of nymphal instars are described for a Korean wood-feeding cockroach, Cryptocercus kyebangensis. Eleven instars, including adults, were tentatively identified. Female adults had apicolateral emargination and a truncated apical median prominence in the seventh sternite, and female nymphs of the other instars except for the last had a narrowly rounded apical median prominence in the seventh sternite. In the last instar, the seventh sternite was partially desclerotized and somewhat shriveled at the start of the emarginated area. In contrast, males showed no emargination in adults, and had a rounded broad apical median in this area of all instars. In the ninth sternite, female nymphs had a medium notch on the caudal margin and styli were separated before reaching adulthood, whereas no such notch was observed in male nymphs. The styli remained prominent in the ninth sternite of male adults.

Plant Regeneration from Rice Microspore Cultures (벼의 소포자 배양을 통한 식물체 재분화)

  • 김영수
    • Journal of Plant Biology
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    • v.36 no.2
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    • pp.183-192
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    • 1993
  • Efficient plant regeneration system was established through the culture of rice (Oryza sativa L.) microspores. Microspores released by anther shedding culture developed into proembryos and calluses in B5 medium within two weeks of culture. The optimal hormone and carbon sources were dependent on the genotypes used. Microspore's viability decreased rapidly in culture time, therefore less than 3% of the total microspores were viable at the 9th day when the first microspore division was observed. Of two types of microspores (pollen dimorphism) observed in culture, only the P-grain, larger microspores than normal one was able to divide. Using 4',6-diamidino-2-phenylindole (DAPI) fluorescence staining, it was confirmed that the symmetrical division of uninucleate microspore was the first step leading to continuous microspore development. Microspore-derived proembryos and calluses were regenerated to plants in N6 medium containing 1 mg/L NAA and 5 mg/L kinetin, and 78.3% of the regenerated plants were haploids.

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Serum Thyroid Hormone Levels in Wild and Captive Sea Turtles

  • Moon, Dae-Yeon;Mackenzie, Duncan-S.;Owens, David-W.
    • Animal cells and systems
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    • v.2 no.2
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    • pp.177-181
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    • 1998
  • Blood samples collected from green (chelonia mydas), loggerhead (caretta caretta), and Kemp's ridley (Lepidochelys kempii) sea turtles were analyzed by radioimmunoassay to detect seasonal variations in thyroid hormones and compare levels in wild and captive individuals. Sexual dimorphism in the annual cycle of thyroxine was observed in adult Kemp's ridley. No differences were observed between immature male and female green and loggerhead sea turtles. The level of triiodothyronine was consistently low relative to thyroxine in all species investigated, and captive sea turtles exhibit higher plasms thyroid levels than do wild ones.

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Aspergillus candidusF1484 균주가 생산하는 항진균 화합물의 분리 및 특성

  • Kim, Sung-Uk;Lee, So-Young;Kim, Sung-Kyu;Son, Kwang-Hee;Kim, Young-Kook;Moon, Surk-Sik;Bok, Song-Hae
    • Microbiology and Biotechnology Letters
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    • v.24 no.5
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    • pp.574-578
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    • 1996
  • In the course of screening for the antifungal compounds against Candida albicans, an antifungal compound (F1480) was isolated from the culture broth of Aspergillus candidus F1484. Isolation and purification of compound F1484 were performed using ethyl acetate extraction, silica gel column chromatography, ODS column chromatography, and preparative HPLC. The structure of compound F1484 was determined by the spectroscopic analyses of EI-MS, $^{13}$C, $^{1}$H-NMR, DEPT, HMQC, and HMBC. This compound appeared to have a structure of antifungal agent, chloroflavonin. In addition to antifungal activities against the yeast phase of Candida species, compound F1484 showed cytotoxic effect against various human tumor cell lines.

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Copepods of the Genus Leptocaris (Harpacticoida: Darcythompsoniidae) from Salt Marshes in South Korea

  • Lee, Ji-Min;Chang, Cheon-Young
    • Animal Systematics, Evolution and Diversity
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    • v.24 no.1
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    • pp.89-98
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    • 2008
  • Two copepod species of Leptocaris belonging to the family Darcythompsoniidae are recorded from sandy mud sediments of salt marshes in South Korea: L. brevicornis (van Douwe, 1905) and L. trisetosus pacificus n. ssp. The genus Leptocaris is newly known from Korea. Leptocaris trisetosus pacificus differs from the nominate subspecies in exhibiting a sexual dimorphism in setal armature of leg 3, that is, bearing an additional seta on the second endopodal segment of leg 3 in male and an allopatric geographical distribution. This paper deals with the description and systematic accounts of them with detailed illustrations.

Ten species of the subfamily Tephritinae (Insecta: Diptera: Tephritidae) newly recorded in Korea

  • Han, Ho-Yeon
    • Journal of Species Research
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    • v.8 no.3
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    • pp.294-312
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    • 2019
  • A total of 56 genera and 101 species of the fly family Tephritidae have been previously recorded in Korea. As a result of an ongoing study of this family, I report the following ten additional species new to Korea: Actinoptera montana (Meijere, 1924), Actinoptera reticulata Ito, 1984, Campiglossa luxorientis(Hering, 1940), C. melanochroa (Hering, 1941), C. quadriguttata (Hendel, 1927), C. shensiana (Chen, 1938), Oxyna gansuica Wang, 1998, Tephritis jocaste Hering, 1953, Tephritis okera (Shinji, 1940), and Trupanea guttistella (Hering, 1951). Among the five genera involved here, the genus Actinoptera Rondani, 1871 is recognized for the first time in Korea. Therefore, 57 genera and 111 species are now officially recognized for the Korean tephritid fauna. For each newly recognized Korean species, I provide new Korean name, synonymy, taxonomic diagnosis and color photographs. When possible, I list the host records and discuss their intraspecific variability and sexual dimorphism.

Morphology and distribution of antennal, maxillary palp and labial palp sensilla of the adult bruchid beetles, Callosobruchus chinensis (L.) (Coleoptera: Bruchidae)

  • WANG, Hongmin;ZHENG, Haixia;ZHANG, Yaowen;ZHANG, Xianhong
    • Entomological Research
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    • v.48 no.6
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    • pp.466-479
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    • 2018
  • Callosobruchus chinensis (Coleoptera: Bruchidae) is the main pest of mungbean (Vigna radiata) especially during seed storage. To provide background information for chemical ecology studies, we examined the externalmorphology of the antennal, maxillary palp and labial palp sensilla of this insect with scanning electron microscopy. The antennae of adult C. chinensis exhibited sexual dimorphism. The female have serrated antenna and the male have pectinate morphology. Eight sensillum types have been observed on the antennae of both sexes: $B\ddot{o}hm$ bristles, sensilla chaetica, sensilla trichodea, sensilla basiconica, sensilla styloconicum, sensilla coeloconica, sensillum campaniformia, sensilla cavity. There are no differences on the morphology of maxillary palp and labial palp between female and male. Four different types of sensilla are present on the labial and maxillary palps of both sexes of C. chinensis: sensilla chaetica, sensilla twig basiconica, sensilla basiconica, sensilla digitiformia.