The Experts below are selected from a list of 459 Experts worldwide ranked by ideXlab platform
Jeanpol Frippiat - One of the best experts on this subject based on the ideXlab platform.
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The urodele amphibian Pleurodeles waltl has a diverse repertoire of immunoglobulin heavy chains with polyreactive and species-specific features
Developmental and Comparative Immunology, 2015Co-Authors: Coralie Fonte, Arnaud Gruez, Stephanie Ghislin, Jeanpol FrippiatAbstract:Urodele amphibians are an interesting model because although they possess the cardinal elements of the vertebrate immune system, their immune response is apparently subdued. This phenomenon, sometimes regarded as a state of immunodeficiency, has been attributed by some authors to limited antibody diversity. We reinvestigated this issue in Pleurodeles waltl, a metamorphosing urodele, and noted that upsilon transcripts of its IgY repertoire were as diverse as alpha transcripts of the mammalian IgA repertoire. Mu transcripts encoding the IgM repertoire were less diverse, but could confer more plasticity. Both isotypes present potential polyreactive features that may confer urodele antibodies with the ability to bind to a variety of antigens. Finally, we observed additional cysteines in CDR1 and 2 of the IGHV5 and IGHV6 domains, some of which specific to urodeles, that could allow the establishment of a disulfide bond between these CDRs. Together, these data suggest that urodele antibody diversity is not as low as previously thought.
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igx antibodies in the urodele amphibian ambystoma mexicanum
Developmental and Comparative Immunology, 2008Co-Authors: Berenice Schaerlinger, Jeanpol FrippiatAbstract:Until recently, it was believed that urodele amphibians are able to synthesize only two immunoglobulin isotypes, IgM and IgY. We reinvestigated this issue in the Iberian ribbed newt Pleurodeles waltl and reported recently that this urodele expresses at least three isotypes: IgM, IgP and IgY. In this study, we demonstrate that another urodele, Ambystoma mexicanum, has also a third isotype whose amino acid sequence presents the highest homology with the amino acid sequence of Xenopus IgX. This isotype has typical Ig H-chain characteristics, could form multimers and is mainly expressed in mucosal tissues thereby indicating that it is likely the physiological counterpart of Xenopus IgX and mammalian IgA. Interestingly, no IgP could be found in A. mexicanum, in contrast to P. waltl, in which IgX was not found in previous investigations. These data indicate, for the first time, that different families of urodeles can express different immunoglobulin isotypes.
Tomofumi Inokuchi - One of the best experts on this subject based on the ideXlab platform.
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purification and molecular cloning of aspartic proteinases from the stomach of adult japanese fire belly newts cynops pyrrhogaster
Journal of Biochemistry, 2016Co-Authors: Tatsuki Nagasawa, Kaori Sano, Mari Kawaguchi, Kenichiro Kobayashi, Shigeki Yasumasu, Tomofumi InokuchiAbstract:Six aspartic proteinase precursors, a pro-cathepsin E (ProCatE) and five pepsinogens (Pgs), were purified from the stomach of adult newts (Cynops pyrrhogaster). On sodium dodecylsulfate-polyacrylamide gel electrophoresis, the molecular weights of the Pgs and active enzymes were 37-38 kDa and 31-34 kDa, respectively. The purified ProCatE was a dimer whose subunits were connected by a disulphide bond. cDNA cloning by polymerase chain reaction and subsequent phylogenetic analysis revealed that three of the purified Pgs were classified as PgA and the remaining two were classified as PgBC belonging to C-type Pg. Our results suggest that PgBC is one of the major constituents of acid protease in the urodele stomach. We hypothesize that PgBC is an amphibian-specific Pg that diverged during its evolutional lineage. PgBC was purified and characterized for the first time. The purified urodele pepsin A was completely inhibited by equal molar units of pepstatin A. Conversely, the urodele pepsin BC had low sensitivity to pepstatin A. In acidic condition, the activation rates of newt pepsin A and BC were similar to those of mammalian pepsin A and C1, respectively. Our results suggest that the enzymological characters that distinguish A- and C-type pepsins appear to be conserved in mammals and amphibians.
Kevin P Mulder - One of the best experts on this subject based on the ideXlab platform.
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the complete mitochondrial genome of salamandra salamandra amphibia Urodela salamandridae
Mitochondrial DNA Part B, 2016Co-Authors: Kevin P Mulder, Andre Lourenco, Miguel Carneiro, Guillermo VeloantonAbstract:The complete mitochondrial genome of Salamandra salamandra was reconstructed using bycatch sequences from an RNAseq library generated from muscle tissue. This study shows the potential of using dat...
David M Gardiner - One of the best experts on this subject based on the ideXlab platform.
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analysis of the expression and function of wnt 5a and wnt 5b in developing and regenerating axolotl ambystoma mexicanum limbs
Development Growth & Differentiation, 2008Co-Authors: Sukla Ghosh, Stephane Roy, Carl Seguin, Susan V Bryant, David M GardinerAbstract:Urodele amphibians are unique adult vertebrates because they are able to regenerate body parts after amputation. Studies of urodele limb regeneration, the key model system for vertebrate regeneration, have led to an understanding of the origin of blastema cells and the importance of positional interactions between blastema cells in the control of growth and pattern formation. Progress is now being made in the identification of the signaling pathways that regulate dedifferentiation, blastema morphogenesis, growth and pattern formation. Members of the Wnt family of secreted proteins are expressed in developing and regenerating limbs, and have the potential to control growth, pattern formation and differentiation. We have studied the expression of two non-canonical Wnt genes, Wnt-5a and Wnt-5b. We report that they are expressed in equivalent patterns during limb development and limb regeneration in the axolotl (Ambystoma mexicanum), and during limb development in other tetrapods, implying conservation of function. Our analysis of the effects of ectopic Wnt-5a expression is consistent with the hypothesis that canonical Wnt signaling functions during the early stages of regeneration to control the dedifferentiation of stump cells giving rise to the regeneration-competent cells of the blastema.
Matsui Masafumi - One of the best experts on this subject based on the ideXlab platform.
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Two new species of Tylototriton from Thailand (Amphibia: Urodela: Salamandridae)
2013Co-Authors: Nishikawa Kanto, Khonsue Wichase, Pomchote Porrawee, Matsui MasafumiAbstract:Nishikawa, Kanto, Khonsue, Wichase, Pomchote, Porrawee, Matsui, Masafumi (2013): Two new species of Tylototriton from Thailand (Amphibia: Urodela: Salamandridae). Zootaxa 3737 (3): 261-279, DOI: http://dx.doi.org/10.11646/zootaxa.3737.3.
