• Journal of Photoscience
• /
• 제9권2호
• /
• pp.63-65
• /
• 2002

This report concerns a putative role of mycosporine-like amino acids (MAA) as natural scavengers of singlet oxygen ($^1$O$_2$) in marine organisms. MAA prepared from the ascidian Lissoclinum patella were found to protect biological systems against detrimental effects of the type II photosensitization in vitro. L. patella MAA were resolved into five components, and the relative $^1$0$_2$ quenching efficiencies were measured for three major components in aqueous media. It turned out that they were all effective in scavenging $^1$0$_2$, to different degrees albeit. The results suggest that physiological relevance of MAA in marine organisms may be found in a 'built-in' defense against photooxidative effects of sunlight.

• Journal of Photoscience
• /
• 제9권2호
• /
• pp.261-263
• /
• 2002

The presence of retinals (retinal and 3,4-didehydroretinal) has been known in the eggs of wide range of oviparous vertebrates, but the biological significance of the egg retinals has yet to be clarified. We here show that retinals are the major components of retinoids in the eggs of all species of chordate animals we examined. The egg retinals were commonly bound to egg yolk proteins, the storage proteins, via a Schiff base linkage. The Schiff base linkage, which protects the reactive aldehyde group, would negate the toxicity of aldehyde, and enable to accumulate much amount of retinals. The retinals in chordate eggs are considered to be the precursor of functional retinoids, such as photoreceptive pigment chromophores and retinoic acid, during development. The results of the present research strongly suggest that retinals in the eggs of oviparous chordates are the common and essential mode of retinoid storage.

• 한국수산과학회지
• /
• 제40권2호
• /
• pp.68-72
• /
• 2007

The flow properties of sulfated polysaccharides purified from the ascidian Halocynthia roretzi tunic were investigated. The sulfated polysaccfarides produced aqueous solutions of low apparent viscosity with pseudoplastic flow behavior. The respective activation energies of TCA-treated and TCA-nontreated solutions were $2.2248{\times}10^4\;and\;1.442{\times}10^4J/kg{\cdot}mol$ at a 150L/s shear rate. The viscosity of the sulfated polysaccharides solution was increased by the addition of sugar, while it was not changed by the addition of NaCl.

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

• Animal Systematics, Evolution and Diversity
• /
• 제31권1호
• /
• pp.1-7
• /
• 2015

Colonial ascidians, Clavelina elegans (Oka, 1927) and Clavelina miniata Watanabe & Tokioka, 1973 are reported for the first time in Korean waters. As a result of this study, three species of the genus Clavelina are now recorded in Korean fauna. Clavelina elegans and C. miniata have been reported only from Japan. We expanded the distribution range of these species to Korea. The specimens of C. elegans and C. miniata were collected from the subtidal zone of Beomseom and Chagwido in Jeju-do by SCUBA diving. Detailed descriptions, illustrations and photographs of these species are provided in this paper.

• Animal cells and systems
• /
• 제4권2호
• /
• pp.105-107
• /
• 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 Systematics, Evolution and Diversity
• /
• 제14권2호
• /
• pp.105-116
• /
• 1998

이화여자대학교 생물과학과에 보관중인 해초류(피낭류)로부터 요각류 2 미기록종이 발견되어 재기재하였다. 이 중에서 Doroixys uncinata Kerschner, 1879는 만두멍게과에 속하는 군체멍게인 미끈만두멍게[Aplidium glabrum(verrill,1871)]의 test로부터 발견되었고, Doropygus rigidus Ooishi, 1962는 미더덕과에 속하는 단체멍에인 유두멍게[Cnemidocarpa irene(Hartmeyer, 1906)]와 세줄미더덕(Styela tokiokai Nishikawa, 1991)의 새낭에서 발견되었다.

• Animal Systematics, Evolution and Diversity
• /
• 제12권4호
• /
• pp.397-466
• /
• 1996

동해안에서 잡힌 Artotrogidae과의 요각류 17종을 기록하였다. 이들은 Artotrogus 속의 4신종, Bradypontius속의 3신종, Cryptopontius속의 4신종, Myzopontius 속의 1신종 1미기록종, Pteropontius속의 1신종 1미기록종, 1신속에 속하는 2신종이다. 두 미기록종은 Myzopontius pungens Giesbrecht와 Pteropontius decorus Ho이다. 이들 17종은 태형동물 2종, 멍게 1종, 해초, 그리고 항구에 가라낮아 있던 폐그물로부터 채집된 것들이다. Artotrogus속의 분류에 대해서도 재검토하였다.

• 약학회지
• /
• 제5권1호
• /
• pp.45-50
• /
• 1960

Some enzymatic properties of Cynthia roretzi v. (Drasche Korean : U-Rung-Shei) was studied by author and obtained the following results; 1. The optimum pH of the digestive gland amylase was 6.8-7.0 2. Activity of metallic ion on the amylase showed the following order; 10$^{-3}$ M M $n^{++}$>10$^{-3}$ M $Co^{++}$>10$^{-4}$ M $Mg^{++}$>10$^{-4}$ M $Ca^{++}$>10$^{-2}$ M Z $n^{++}$>10$^{-2}$ M P $b^{++}$ 3. The digestive gland enzyme inactivated at 70.deg. C. 4. When the enzyme concentration increase 2 times, the enzymatic activity also increase, but not propertionally. 5. The digestine gland amylase showed remarkably higher enzymatic activity than the intestinal amylase. 6. The digestive gland amylase from the ascidian showed remarkably higher enzymatic activity than the heptancreatic amylase from shell fish (Turbo (Batillus) Cornutus Solander).nder).nder).

• 한국식품과학회지
• /
• 제15권1호
• /
• pp.1-5
• /
• 1983

흰멍게, Styela plicata의 정미성분(呈味成分)의 함량(含量)을 밝히기 위하여 육(肉)과 피(皮)중의 핵산관련물질(核酸關聯物質), 유리(遊離)아미노산(酸), betaine, TMAO, TMA, total creatinine의 함량(含量)을 분석(分析) 검토(檢討)하였다. 핵산관련물질(核酸關聯物質)의 함량(含量)은 육(肉)에서 AMP가 $1.2{\mu}mole/g$으로 가장 많았다. 그리고 IMP도 $0.8{\mu}mole/g$으로 상당히 많이 함유(含有)되어 있었다. 피(皮)에서도 같은 경향(傾向)이었지만 그 함량(含量)이 육(肉)에 비(比)하여 아주 적었다. 육(肉)중에 다량(多量)으로 함유(含有)된 유리(遊離)아미노산(酸)은 proline, alanine, glutamic acid 및 serine으로서 이들 5종(種)의 유리(遊離)아미노산(酸)이 전체(全體) 유리(遊離)아미노산(酸)의 72%를 차지하였다. 피(皮)에서도 이들 유리(遊離)아미노산(酸)이 전체(全體) 유리(遊離)아미노산(酸)의 82%를 차지하였으나 그 함량(含量)은 육(肉)의 약(約) 1/10 정도에 불과(不過)하였다. 육(肉)중의 betaine 질소량(窒素量)은 16.4mg/100g으로서 육(肉)의 전체(全體)엑스분질소량(分窒素量)의 6.1%를 차지하였다. 피(皮)에서는 0.9mg/100g으로서 그 함량(含量)이 아주 낮았다. TMAO 및 TMA는 그 함량(含量)이 비교적(比較的) 미량(微量)이었다. total creatinine 질소량(窒素量)은 육(肉)과 피(皮)에서 각각(各各) 5.8mg/100g 및 1.1mg/100g으로서 전체(全體)엑스분질소량(分窒素量)의 2%정도였다.