• 제목/요약/키워드: vertebrate

검색결과 220건 처리시간 0.02초

Insight into Rhodopsin Diversity from Viewpoint of Counterion

  • Terakita, Akihisa
    • Journal of Photoscience
    • /
    • 제9권2호
    • /
    • pp.33-36
    • /
    • 2002
  • In vertebrate rhodopsins the glutamic acid at position 113 serves as a counterion to stabilize the protonated retinylidene Schiff base linkage and to shift the spectrum to the visible region. Invertebrate rhodopsins and retinochrome have the amino acid residue different from glutamic acid or asparatic acid at this position and therefore, these pigments may have a counterion at different position. We first investigated the counterion in retinochrome by site specific mutagenesis. The results showed that the counterion is the glutamic acid at position 181, where almost of all the pigments including vertebrate and invertebrate rhodopsins in the rhodopsin family have a glutamic acid or an aspartic acid. In vertebrate rhodopsins, however, Glu 181 does not act as a counterion, and the red-sensitive cone pigments have a histidine at this position, which serves as a chloride-binding site for red-shift of the absorption spectrum. These findings suggested that the role of Glu181 as a counterion may be weakened by the newly acquired counterion at position 113. Taken together with our recent studies on an invertebrate-type rhodopsin, the rhodopsin diversity was discussed from viewpoint of counterion.

  • PDF

Molecular Co-evolution of Gonadotropin-releasing Hormones and Their Receptors

  • Seong, Jae-Young;Kwon, Hyuk-Bang
    • Animal cells and systems
    • /
    • 제11권2호
    • /
    • pp.93-98
    • /
    • 2007
  • Gonadotropin-releasing hormone (GnRH), synthesized in the hypothalamus, plays a pivotal role in the regulation of vertebrate reproduction. Since molecular isoforms of GnRH and their receptors (GnRHR) have been isolated in a broad range of vertebrate species, GnRH and GnRHR provide an excellent model for understanding the molecular co-evolution of a peptide ligand-receptor pair. Vertebrate species possess multiple forms of GnRH, which have been created through evolutionary mechanisms such as gene/chromosome duplication, gene deletion and modification. Similar to GnRHs, GnRH receptors (GnRHR) have also been diversified evolutionarily. Comparative ligand-receptor interaction studies for non-mammalian and mammalian GnRHRs combined with mutational mapping studies of GnRHRs have aided the identification of domains or motifs responsible for ligand binding and receptor activation. Here we discuss the molecular basis of GnRH-GnRHR co-evolution, particularly the structure-function relationship regarding ligand selectivity and signal transduction of mammalian and non-mammalian GnRHRs.

The vertebrate fauna along the Hantangang (river) of Korea

  • Jo, Yeong-Seok;Kim, Byung-Jik;Hur, Wee-Haeng;Won, Chang-Man
    • Journal of Species Research
    • /
    • 제1권1호
    • /
    • pp.87-99
    • /
    • 2012
  • Before the construction of Hantangang dam, we surveyed vertebrate fauna along the Hantangang River and collected samples. We collected 248 specimens (1,394 individuals) of 41 fish species from 10 families in four orders, including 17 endemic species and 5 endangered species. In our herpetofauna survey, we collected 47 amphibian samples of 10 species from 5 families in 2 orders, and 19 reptile samples of 5 species from 2 families in 1 order. We observed 25 species of bird (6 orders, 14 families) inclulding collection of 51 bird specimens (10 species from 5 families in 1 order). We collected 91 mammals of 6 species, and identified 7 species from field sign and direct observation from a total of 10 families in 5 orders. This collection and list comprise the final vertebrate faunal survey of the Hantangang region, and will provide basic scientific information for future research on conservation and restoration of the region.

수종척추동물의 LDH isozyme에 대한 비교생화학적 연구 (Comparison of LDH isozymes in several vertebrates)

  • 임중기
    • 약학회지
    • /
    • 제16권1호
    • /
    • pp.34-46
    • /
    • 1972
  • Lactate dehydrogenase isozymes in heart, kidney, liver and skeletal muscle of 15 species of vertebrate animals belonging to 5 classes were separated by cellulose acetate electrophoresis and the levels of them were measured and compared with each other. Lactate dehydrogenase isozyme patterns were different from each other among animal species and among tissues. The activity of LDH$_{5}$ was superior in anaerobic tissues such as liver and skeletal muscle, and the activity of LDH$_{1}$ was superior in aerobic tissues such as heart and kidney. The level of LDH of vertebrate animals of the 5 classes has found approximatry increasing in the following order: Pisces>Amphibia>Reptelia

  • PDF

망막 외망층의 국부회로에 대한 신경망 모델 및 컴퓨터 모의실험 (Neural Network Modelling and Computer Simulation of the Local Circuits of the Outer Plexiform Layer in a Vertebrate Retina)

  • 이일병
    • 대한의용생체공학회:의공학회지
    • /
    • 제9권1호
    • /
    • pp.17-24
    • /
    • 1988
  • This paper describes a neural network modelling of a vertebrate retina using a discrete-time and discrete-space approach based on neuro-anatomical data, and the computer simulations of the model which approximate the frog/amphibian negro-physiological data. It then compares them and describes how such a model can be beneficially used for confirming the hypothesis of a given neural system and further predict yet unknown experimental data.

  • PDF

NMR-based Metabolomic Responses of Zebrafish (Danio Rerio) by Fipronil Exposure

  • Lee, Sujin;Oh, Sangah;Kim, Seonghye;Lee, Wonho;Choi, Juyoung;Lee, Hani;Lee, Yujin;Kim, Suhkmann
    • 한국자기공명학회논문지
    • /
    • 제24권4호
    • /
    • pp.104-116
    • /
    • 2020
  • Fipronil, the phenylpyrazole insecticide, is effective and used in various fields. Especially, fipronil was reliable because it was known to be specific on invertebrate animals than vertebrate animals including mammals. However, fipronil had potential risks that affect vertebrate animals as it blocks the gamma-aminobutyric acid (GABA) receptors that also exists in vertebrates as well as invertebrates. Therefore, it was necessary that harmful effects of fipronil on vertebrates are clarified. For this purpose, the zebrafish (Danio rerio) were used on behalf of vertebrate animals in present study. The zebrafish were exposed to 5 ㎍/L, 25 ㎍/L, and 50 ㎍/L of fipronil during 12, 24 and 72 hours. To closely observe toxic process, 12 hours and 24 hours of additional time point were set in the exposure test. Nuclear magnetic resonance (NMR)-based metabolomics is an approach to detect metabolic changes in organism resulted from external stimuli. In this study, NMR-based metabolomics showed the metabolic changes in zebrafish caused by fipronil exposure. Metabolic analysis revealed that fipronil interfered with energy metabolism and decreased the antioxidant ability in zebrafish. Antioxidant ability decline was remarkable at high exposure concentration. In addition, metabolic analysis results over time suggested that reactions for alleviating the excessive nerve excitation occurred in zebrafish after fipronil exposure. Through this study, it was elucidated that the adverse effects of fipronil on vertebrate animals are evident. The risk of fipronil on vertebrates can be no longer ignored. Moreover, this study has a meaning of practically necessary research for organism by examining the effects of fipronil at low concentrations existed in real environment.

Composite Dependency-reflecting Model for Core Promoter Recognition in Vertebrate Genomic DNA Sequences

  • Kim, Ki-Bong;Park, Seon-Hee
    • BMB Reports
    • /
    • 제37권6호
    • /
    • pp.648-656
    • /
    • 2004
  • This paper deals with the development of a predictive probabilistic model, a composite dependency-reflecting model (CDRM), which was designed to detect core promoter regions and transcription start sites (TSS) in vertebrate genomic DNA sequences, an issue of some importance for genome annotation. The model actually represents a combination of first-, second-, third- and much higher order or long-range dependencies obtained using the expanded maximal dependency decomposition (EMDD) procedure, which iteratively decomposes data sets into subsets on the basis of dependency degree and patterns inherent in the target promoter region to be modeled. In addition, decomposed subsets are modeled by using a first-order Markov model, allowing the predictive model to reflect dependency between adjacent positions explicitly. In this way, the CDRM allows for potentially complex dependencies between positions in the core promoter region. Such complex dependencies may be closely related to the biological and structural contexts since promoter elements are present in various combinations separated by various distances in the sequence. Thus, CDRM may be appropriate for recognizing core promoter regions and TSSs in vertebrate genomic contig. To demonstrate the effectiveness of our algorithm, we tested it using standardized data and real core promoters, and compared it with some current representative promoter-finding algorithms. The developed algorithm showed better accuracy in terms of specificity and sensitivity than the promoter-finding ones used in performance comparison.