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

• BMB Reports
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• 제39권5호
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• pp.511-515
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• 2006

Alanine aminotransferase (AAT) is mainly synthesized in the liver, and its level in mammalian serum is elevated after acute phase induction. Here we demonstrated that sheep anti-human AAT antibody cross-reacted with amphioxus humoral fluids as well as human serum; and the concentration of AAT in the humoral fluids in amphioxus increased after the acute challenge with lipopolysaccharide, while the level of total proteins remains unchanged. These suggest the presence of the same acute phase response pattern in amphioxus, as observed in some mammalian species. Immunohistochemically, AAT was localized in the hepatic diverticulum, ovary and testis. It appears that the hepatic diverticulum in amphioxus is functionally homologous to the vertebrate liver in respect of AAT synthesis, supporting the hypothesis that the vertebrate liver evolved from the hepatic diverticulum of an amphioxus-like ancestor during early chordate evolution.

• 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.

• 수산해양교육연구
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• 제28권4호
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• pp.903-912
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• 2016

Hagfish which belongs to the chordate contact cyclostomata, is important phylogenetic relationship between vertebrate and invertebrate. Cathepsins of the cysteine protease family have traditionally been thought to play a major role in intracellular protein degradation and turnover in lysosomes. In this study, Catepsin L was cloned from Inshore hagfish (Eptatretus burgeri), the cDNA encoding ORF of the Eptatretus burgeri Cathepsin L (EbCtL) is 978 bp. The cDNA encoding proEbCtL was expressed in Escherichia coli strain BL21(DE3) using the pGEX-4T-1 expression vector system. The recombinant proEbCtL protein was overexpressed as a approximately 55 kDa fusion protein. The overproduced soluble GST-fusion protein was then applied to glutathione-Sepharose 4B column chromatography; the sample harboring the fusion protein evidenced a high degree of purity when analyzed via SDS-PAGE and Western blot analysis. Its activity was quantied by cleaving the synthetic peptide Z-FR-AMC, Z-LLE-AMC, and Suc-AAF-AMC, and the optimal pH for the protease activity was 8, 9.5, and 9, respectively.

• 한국발생생물학회지:발생과생식
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• 제6권2호
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• pp.77-82
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• 2002

원시적인 척삭동물인 멍게에서 초기 배 세포운명은 모성 세포질인자와 유도적 상호작용에 의하여 결정된다. 매우 단순한 구조를 하고 있는 멍게 올챙이형 유생의 주요한 중배엽 조직으로 척삭, 근육 및 간충직이 존재한다. 근육 세포의 형성은 세포의 자율적인 과정으로, 초기 배의 후부 가장자리에 국재하는 모성 macho-1 mRNA에 의하여 근육 세포의 운명이 결정된다. 이에 반하여, 내배엽 전구세포의 유도작용은 척삭과 간충직 세포의 운명결정에 있어서 중요한 역할을 한다. FGF-Ras-MAPK 신호전달 과정은 이들 조직의 유도에 관여한다. 간충직과 척삭 전구세포에서 FGF신호에 대한 반응성의 차이는 난자의 후방 식물극 세포질에서 유래하는 인자의 존재 또는 부재에 의하여 야기된다. 간충직과 척삭 세포의 유도에 있어서, 지시적 인 신호는 유도신호를 받은 세포를 극성 화하고, 서로 다른 세포운명을 가진 두 개의 딸세포가 형성 되도록 비대칭 세포분열을 촉진한다.

• 한국수산과학회지
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• 제48권6호
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• pp.913-919
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• 2015

In vertebrates, the vitamin D receptor (VDR), a member of the nuclear receptor superfamily, binds the biologically active ligand $1{\alpha},25-(OH)_2$-vitamin $D_3$ (1,25 $D_3$). Nearly all vertebrates, including Agnatha, possess a VDR with high ligand selectivity for 1,25 $D_3$ and related metabolites. Although a putative ancestral VDR gene is present in the genome of the chordate invertebrate Ciona intestinalis, the functional characteristics of marine invertebrate VDR are still obscure. To elucidate the ascidian Halocynthia roretzi VDR (HrVDR), we cloned full-length HrVDR cDNA and investigated the transcriptional activity of HrVDR in HEK293 cells. HrVDR consists of 1,680 nucleotides (559 amino acids [aa]), including a short N-terminal region (A/B domain; 26 aa), DNA-binding domain (C domain; 72 aa), hinge region (D domain; 272 aa), and C-terminal ligand-binding domain (E domain; 161 aa). The amino acid sequence identity of HrVDR was greatest to that of C. intestinalis VDR (56%). In the luciferase reporter assays, the transcriptional activity of HrVDR was not significantly increased by 1,25 $D_3$, whereas the farnesoid X receptor agonist GW4064 increased the transactivation of HrVDR. These results suggest the presence of a novel ligand for and a distinct ligand-binding domain in ascidian VDR.