• 한국동물학회:학술대회논문집
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• 한국동물학회 1997년도 한국생물과학협회 학술발표대회
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• pp.110.1-110
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• 1997

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.37-42
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• 2002

In ascidians, a primitive chordate, maternal cytoplasmic factors and inductive interactions are involved in the specification of cell fate in early embryos. The larval structure of ascidians is relatively simple, and the major mesodermal tissues of the tadpole larva are notochord, muscle and mesemchyme. Formation of muscle cells is a cell-autonomous process, and localized maternal macho-1 mRNA specify muscle fate in the posterior marginal zone of the early embryo. In contrast, inductive influence from endoderm precursors plays important roles in the specification of notochord and mesenchyme fates. FGF-Ras-MAPK signaling is involved in the induction of both tissues. The difference in responsiveness of the posterior mesenchyme and anterior notochord precursors is caused by the presence or absence of the posterior-vegetal egg cytoplasm, respectively. In these cases, directed signal may polarizes the responding cells and cause asymmetric cell divisions that operate in both the anterior and posterior regions.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1996년도 한국생물과학협회 국제학술대회
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• pp.80.1-80
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• 1996

No Abstract, See Full Text

• Animal Systematics, Evolution and Diversity
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• 제16권1호
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• pp.39-53
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• 2000

1994년 7월부터 1999년 6월까지 대한해협의 당사 및 인근수역에서 본인과 연구팀에 의해 조간대와 잠수 및 SCUBA 잠수등으로 수행되었다. 채집된 재료는 8과 17속 30종으로 동정 분류 되었고, 이 중 한 종, 주머니가죽멍게(Molgula hozawai)은 한국미기록 종이었으며, 그 외 29종은 당사 및 인근 수역에서는 처음으로 밝혀지는 종들이다. 이 지역 해초류의 생물지리학적 분포를 보면 30종 모두가 우리나라 천해종이며 난수역 종이다. 이들 중 23종은 거제도에서 이미 보고된 종이고, 12종은 춘도에서 보고되었으며, 6종 일로툼멍게(Eudistoma illotum), 새공멍게(Symplegma connec-tans), 가로줄멍게(Boltenia transversaria), 우주멍게(Microcosmus multitentacluatus), 네모가죽멍게(Pyura squamata)와 주머니가죽빛멍게(Molgula hozawai)는 이들 3개 난수역 지역에서는 처음으로 보고된 종이다. 그리고 11종(37%)은 3개 지역에 공통으로 나타났고 12종(40%)은 당사와 거제도에 공통이며, 한종(3%), 두줄미더덕(Styela canopus)은 당사와 춘도에서 공통종으로 나타났다. 따라서 당사 및 인근 수역의 해초류는 거제도와 춘도의 해초류상과 아주 유사하며 이는 이들 지역이 거의 같은 위도(북위 34$^{\circ}$ 40'- 35$^{\circ}$ 22', 동위 128$^{\circ}$ 45' - 129$^{\circ}$ 27')에 위치하고 있어 북상하는 따뜻한 쿠로시오 난류의 영향을 받기 때문으로 사료된다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1997년도 한국생물과학협회 학술발표대회
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• pp.89.1-89
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• 1997

No Abstract, See Full Text

• 한국어병학회지
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• 제7권2호
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• pp.83-94
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• 1994

한국 양식산 우렁쉥이의 외투강에서 채집된 기생성 요각류 1 종이 Bonnierilla 속의 신종임이 확인되어 B. namhaesius 으로 명명하였다. 본 종은 제 1 안테나 8 개 마디의 강모식 3, 17+1 hook, 9+1 aesthete 5, 3, 2, 2+1 aesthete, 7+1 aesthete 를 갖는 점과 제 2 외지에서 제 4 외지 마지막 마디의 II, 5 및 caudal ramu 의 끝 부분에 2, 3, I의 형태를 갖으므로서 다른 종과 구별된다. 또한 Bonnierilla 속 중에서 수컷은 두번째로, 유생은 처음으로 기재한다.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.665-671
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• 2005

Initiation and activation of sperm motility are prerequisite processes for the contact and fusion of male and female gametes at fertilization. The phenomena are under the regulation of cAMP and $Ca^{2+}$ in vertebrates and invertebrates. Mammalian sperm requires $Ca^{2+}$ and cAMP for the activation of sperm motility. Cell signaling for the initiation and activation of sperm motility in the ascidians and salmonid fishes has drawn much attention. In the ascidians, the sperm-activating and attracting factors from unfertilized egg require extracellular $Ca^{2+}$ for activating sperm motility and eliciting chemotactic behavior toward the egg. On the other hand, the cAMP-dependent phosphorylation of protein is essential for the initiation of sperm motility in salmonid fishes. A decrease of the environmental $K^+$ concentration surrounding the spawned sperm causes $K^+$ efflux and $Ca^{2+}$ influx through the specific $K^+$ channel and dihydropyridine-sensitive L-/T-type $Ca^{2+}$ channel, respectively, thereby leading to the membrane hyperpolarization. The membrane hyperpolarization induces synthesis of cAMP, which triggers further cell signaling processes, such as cAMP-dependent protein phosphorylation, to initiate sperm motility in salmonid fishes. This article reviews the studies on the physiological mechanisms of sperm motility and its cell signaling in aquatic species.

• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.167-198
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• 2022

Ten species of copepods, including nine new species, associated with compound ascidians are recorded from Korean waters. Nine new species can be characterized by their major diagnostic features, as follows: Botryllophilus pentamerus n. sp. by having a five-annulated abdomen; B. paucisetatus n. sp. by the presence of four and three setae on the exopods of right and left leg 1, respectively; Haplostoma quadridens n. sp. by the presence of four lobes on the labrum and one seta plus four spines on the exopods of legs 1-4; H. paucidens n. sp. by the presence of only two spines on the distal segment of the antenna; Enterocola horridus n. sp. by having five setae on the antenna, no seta on the caudal ramus, and two setae on leg 5; E. longicaudatus n. sp. by having long caudal rami which are more than three times as long as wide; Thoracodelphys bisetata n. sp. by the presence of only two setae on the basis of the maxillule; T. cerasta n. sp. by the presence of a large, horn-like process on the distal margin of the basis of leg 2; and Unimeria hirsuta n. sp. by having three setae on the terminal segment of the maxilla. Zygomolgus didemni (Gotto, 1956) previously known only from European waters is reported from Korean waters, with a redescription and illustrations.

• Fisheries and Aquatic Sciences
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• 제20권7호
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• pp.12.1-12.7
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• 2017

Soft tunic syndrome (STS) is a protozoal disease caused by Azumiobodo hoyamushi in the edible ascidian Halocynthia roretzi. Previous studies have proven that combined formalin-hydrogen peroxide ($H_2O_2$) bath is effective in reducing STS progress and mortality. To secure target animal safety for field applications, toxicity of the treatment needs to be evaluated. Healthy ascidians were bathed for 1 week, 1 h a day at various bathing concentrations. Bathing with 5- and 10-fold optimum concentration caused 100% mortality of ascidians, whereas mortality by 0.5- to 2.0-fold solutions was not different from that of control. Of the oxidative damage parameters, MDA levels did not change after 0.5- and 1.0-fold bathing. However, free radical scavenging ability and reducing power were significantly decreased even with the lower-than-optimal 0.5-fold concentration. Glycogen content tended to increase with 1-fold bathing without statistical significance. All changes induced by the 2-fold bathing were completely or partially restored to control levels 48 h post-bathing. Free amino acid analysis revealed a concentration-dependent decline in aspartic acid and cysteine levels. In contrast, alanine and valine levels increased after the 2-fold bath treatment. These data indicate that the currently established effective disinfectant regimen against the parasitic pathogen is generally safe, and the biochemical changes observed are transient, lasting approximately 48 h at most. Low levels of formalin and $H_2O_2$ were detectable 1 h post-bathing; however, the compounds were completely undetectable after 48 h of bathing. Formalin-$H_2O_2$ bathing is effective against STS; however, reasonable care is required in the treatment to avoid unwanted toxicity. Drug residues do not present a concern for consumer safety.

• KSBB Journal
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• 제21권3호
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• pp.194-198
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• 2006

본 연구는 초임계 이산화탄소와 에탄올 보조용매를 사용하여 천연물질에 존재하는 기능성 물질을 효율적으로 분리하여 식품 및 의약산업에 이용할 수 있는 천연 기능성 소재를 제공할 수 있는 가능성을 보여 주었다. 초임계 이산화탄소와 보조용매 에탄올 3 mL/min를 사용하여 멍게로부터 ${\beta}$-carotene을 추출하기 위한 최적의 조건은 $35^{\circ}C$, 350 bar이었으며, 추출물질을 흡착하는 흡착칼럼으로부터 ${\beta}$-carotene을 회수하기 위한 rinse 용매는 methanol이 우수한 결과를 나타내었다. 따라서 초임계 이산화탄소를 사용한 멍게 껍질로부터 ${\beta}$-carotene 추출 공정이 상업화될 경우 기존의 재래식 유기용매 추출법에서 회수한 것에 비해 잔존 유기용매가 없고 환경 친화적 공정으로 식품, 의악품 산업 등의 고품질 원료 소재로 이용될 수 있을 것으로 사료된다.