scholarly journals PCR detection of excision suggests mobility of the medaka fish Tol1 transposable element in the frog Xenopus laevis

2007 ◽  
Vol 89 (4) ◽  
pp. 201-206 ◽  
Author(s):  
AKIRA HIKOSAKA ◽  
AKIHIKO KOGA
Keyword(s):  
Xenopus Laevis ◽  
Transposable Element ◽  
Model Organism ◽  
Full Length ◽  
Medaka Fish ◽  
Helper Plasmid ◽  
Cell Stage ◽  
Wide Range ◽  
Tailbud Stage ◽  
Clawed Frog

SummaryTol1 is a DNA-based transposable element identified in the medaka fish Oryzias latipes and a member of the hAT (hobo/Activator/Tam3) transposable element family. Its mobility has already been demonstrated in the human and mouse, in addition to its original host species. This element is thus expected to be useful in a wide range of vertebrates as a genomic manipulation tool. Herein, we show that the Tol1 element can undergo excision in the African clawed frog Xenopus laevis, a major model organism for vertebrate genetics and developmental biology. An indicator plasmid carrying a Tol1 element was injected into 2- or 4-cell-stage embryos together with either a helper plasmid coding for the full-length Tol1 transposase or a modified helper plasmid yielding a truncated protein, and recovered from tailbud-stage embryos. Deletion of the Tol1 region of the indicator plasmid was observed in the experiment with the full-length transposase, and not in the other case. The deletion was associated with various footprint sequences at breakpoints, as frequently observed with many DNA-based transposable elements. These results indicate that the Tol1 element was excised from the indicator plasmid by catalysis of the transposase, and suggest that the Tol1 element is mobile in this frog species.

Detection of de Novo Insertion of the Medaka Fish Transposable Element Tol2

Genetics ◽  
2000 ◽  
Vol 156 (3) ◽  
pp. 1243-1247
Author(s):  
Akihiko Koga ◽  
Hiroshi Hori
Keyword(s):  
Transposable Element ◽  
Direct Evidence ◽  
De Novo ◽  
Tetracycline Resistance ◽  
Gene Tagging ◽  
Terminal Inverted Repeat ◽  
Medaka Fish ◽  
Wide Range ◽  
Fish Cells ◽  
Target Plasmid

Abstract Tol2 is a terminal-inverted-repeat transposable element of the medaka fish Oryzias latipes. It is a member of the hAT (hobo/Activator/Tam3) transposable element family that is distributed in a wide range of organisms. We here document direct evidence for de novo insertion of this element. A Tol2 clone marked with the bacterial tetracycline-resistance gene was microinjected into fertilized eggs together with a target plasmid, and the plasmid was recovered from embryos. The screening of plasmid molecules after transformation into Escherichia coli demonstrated transposition of tet into the plasmid and, by inference, precise insertion of Tol2 in medaka fish cells. De novo excision of Tol2 has previously been demonstrated. The present study provides direct evidence that the Tol2 element has the entire activity necessary for cut-and-paste transposition. Some elements of the mariner/Tc1 family, another widespread group, have already been applied to development of gene tagging systems in vertebrates. The Tol2 element of the hAT family, having different features from mariner/Tc1 family elements, also has potential as an alternative gene tagging tool in vertebrates.

Excision of the Tol2 transposable element of the medaka fish Oryzias latipes in Xenopus laevis and Xenopus tropicalis

Gene ◽  
2004 ◽  
Vol 338 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Koichi Kawakami ◽  
Kosuke Imanaka ◽  
Mari Itoh ◽  
Masanori Taira
Keyword(s):  
Xenopus Laevis ◽  
Transposable Element ◽  
Oryzias Latipes ◽  
Xenopus Tropicalis ◽  
Medaka Fish

Pattern regulation in isolated halves and blastomeres of early Xenopus laevis

Development ◽  
1983 ◽  
Vol 74 (1) ◽  
pp. 221-234
Author(s):  
H. Kageura ◽  
K. Yamana
Keyword(s):  
Xenopus Laevis ◽  
Calf Serum ◽  
The Other ◽  
Foetal Calf Serum ◽  
Cell Stage ◽  
Macroscopic Appearance ◽  
Xenopus Embryos ◽  
Early Embryos ◽  
Tailbud Stage ◽  
Pattern Regulation

Xenopus embryos at the 2-cell stage were cut into right and left halves, those at the 4-cell stage into dorsal and ventral halves or individual blastomeres, and those at the 8-cell stage into lateral, animal and vegetal halves. Defect embryos, that is, 8-cell embryos from which a particular pair of blastomeres had been removed, were also prepared. These halves, blastomeres and defect embryos were cultured in 50% Leibovitz (L-15) medium supplemented with 10% foetal calf serum and then in 10% Steinberg solution. Their development was determined from their macroscopic appearance when controls reached stage 26 (early tailbud stage) or later. The only halves that could develop into normal larvae or frogs were lateral ones of 2- and 8-cell embryos. An interesting finding was that these halves of 2-cell embryos developed into only half-embryos when cultured in the above Leibovitz medium beyond the beginning of gastrulation. On the other hand, most or all the dorsal and ventral halves at the 4-cell stage and the animal and vegetal quartets at the 8-cell stage did not form normally proportioned embryos. Defect embryos lacking any two blastomeres of the animal half gave rise to nearly normal embryos, whereas those lacking two dorsal or two ventral blastomeres of the vegetal half did not. From the present results and those of studies now in progress, it is concluded that development of blastomeres and halves from these early embryos, except lateral halves from 2- and 8-cell embryos, is not regulative as expected earlier, and that a certain combination of blastomeres is essential for complete pattern regulation.

scholarly journals The hAT-family transposable element, hopper, from Bactrocera dorsalis is a functional vector for insect germline transformation

BMC Genetics ◽  
2020 ◽  
Vol 21 (S2) ◽  
Author(s):  
Alfred M. Handler ◽  
Marc F. Schetelig
Keyword(s):  
Transposable Element ◽  
Fluorescent Protein ◽  
Fruit Fly ◽  
Bactrocera Dorsalis ◽  
Helper Plasmid ◽  
Reading Frame ◽  
Germline Transformation ◽  
Functional Genomic Analysis ◽  
Wide Range ◽  
Dipteran Species

Abstract Background The hopper hAT-family transposable element isolated from the Oriental fruit fly, Bactrocera dorsalis, is distantly related to both the Drosophila hobo element and the Activator element from maize. The original 3120 bp hopperBd-Kah element isolated from the Kahuku wild-type strain was highly degenerate and appeared to have a mutated transposase and terminal sequences, while a second 3131 bp element, hopperBd-we, isolated from a white eye mutant strain had an intact transposase reading frame and terminal sequences consistent with function. Results The hopperBd-we element was tested for function by its ability to mediate germline transformation in two dipteran species other than B. dorsalis. This was achieved by creating a binary vector/helper transformation system by linking the hopperBd-we transposase reading frame to a D. melanogaster hsp70 promoter for a heat-inducible transposase helper plasmid, and creating vectors marked with the D. melanogaster mini-white+ or polyubiquitin-regulated DsRed fluorescent protein markers. Conclusions Both vectors were successfully used to transform D. melanogaster, and the DsRed vector was also used to transform the Caribbean fruit fly, Anastrepha suspensa, indicating a wide range of hopper function in dipteran species and, potentially, non-dipteran species. This vector provides a new tool for insect genetic modification for both functional genomic analysis and the control of insect populations.

scholarly journals Conservation and structural analysis of the Xenopus laevis phospho-proteome

2014 ◽  
Author(s):  
Jeffrey R Johnson ◽  
Silvia D Santos ◽  
Tasha Johnson ◽  
Ursula Pieper ◽  
Andrej Sali ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Protein Conformation ◽  
Cell Biology ◽  
Model Organism ◽  
Molecular Function ◽  
Post Translational Modifications ◽  
Regulatory Interactions ◽  
African Clawed Frog ◽  
Regulate Protein ◽  
Clawed Frog

The African clawed frog Xenopus laevis is an important model organism for studies in developmental and cell biology, including cell-signaling. However, our knowledge of X. laevis protein post-translational modifications remains scarce. Here, we used a mass spectrometry-based approach to survey the phosphoproteome of this species, compiling a list of 3225 phosphosites. We used this resource to study the conservation between the phosphoproteomes of X. laevis and 13 other species. We found that the degree of conservation of phosphorylation across species is predictive of sites with known molecular function, kinase interactions and functionally relevant phospho-regulatory interactions. In addition, using comparative protein structure models, we find that phosphosites within structured domains tend to be located at positions with high conformational flexibility. A fraction of sites appear to occur in inaccessible positions and have the potential to regulate protein conformation.

Pan-African phylogeography of a model organism, the African clawed frog ‘Xenopus laevis’

2015 ◽  
Vol 24 (4) ◽  
pp. 909-925 ◽  
Author(s):  
Benjamin L. S. Furman ◽  
Adam J. Bewick ◽  
Tia L. Harrison ◽  
Eli Greenbaum ◽  
Václav Gvoždík ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Model Organism ◽  
African Clawed Frog ◽  
Pan African ◽  
Clawed Frog

Androgen-induced plasticity at a “vocal” neuromuscular synapse

1994 ◽  
Vol 52 ◽  
pp. 32-33
Author(s):  
Darcy B. Kelley ◽  
Martha L. Tobias ◽  
Mark Ellisman
Keyword(s):  
Xenopus Laevis ◽  
Motor Neurons ◽  
Sexual Differentiation ◽  
Molecular Basis ◽  
Neuromuscular Synapse ◽  
Sexually Dimorphic ◽  
Intracellular Protein ◽  
Developmental Program ◽  
Androgen Action ◽  
Clawed Frog

Brain and muscle are sexually differentiated tissues in which masculinization is controlled by the secretion of androgens from the testes. Sensitivity to androgen is conferred by the expression of an intracellular protein, the androgen receptor. A central problem of sexual differentiation is thus to understand the cellular and molecular basis of androgen action. We do not understand how hormone occupancy of a receptor translates into an alteration in the developmental program of the target cell. Our studies on sexual differentiation of brain and muscle in Xenopus laevis are designed to explore the molecular basis of androgen induced sexual differentiation by examining how this hormone controls the masculinization of brain and muscle targets.Our approach to this problem has focused on a highly androgen sensitive, sexually dimorphic neuromuscular system: laryngeal muscles and motor neurons of the clawed frog, Xenopus laevis. We have been studying sex differences at a synapse, the laryngeal neuromuscular junction, which mediates sexually dimorphic vocal behavior in Xenopus laevis frogs.

scholarly journals Applicability of Honey on Silkworms (Bombyx mori) and Quality Improvement of Its Biomaterials

2021 ◽  
Vol 11 (10) ◽  
pp. 4613
Author(s):  
Gabriela-Maria Baci ◽  
Alexandra-Antonia Cucu ◽  
Adela Ramona Moise ◽  
Daniel Severus Dezmirean
Keyword(s):  
Quality Improvement ◽  
Bombyx Mori ◽  
Human Health ◽  
Recombinant Proteins ◽  
Therapeutic Agent ◽  
Life Sciences ◽  
Model Organism ◽  
Medical Field ◽  
Wide Range ◽  
Ancient Times

Since ancient times, honey has been considered one of the most illustrious and esteemed natural products. Honey plays two key roles; specifically, it is an appreciated nutritional product, and also exhibits a wide range of beneficial properties for human health as a therapeutic agent. Furthermore, it has been shown that honey has valuable effects on the biological and physiological features of mulberry silkworms (Bombyx mori). Bombyx mori exhibits importance not only for the economy, but it also serves as an important biotechnological bioreactor for the production of recombinant proteins that have a great impact in the medical field and beyond. It also represents an important model organism for life sciences. In view of the fact that silk fibroin serves as a natural biopolymer that displays high biocompatibility with human organisms and due to honey’s various and remarkable properties for human health, the two elements are currently used together in order to develop ideal biomaterials for a wide range of purposes. In this review, by discussing the applicability of honey on Bombyx mori and beyond, the importance of honey for life sciences and related fields is spotlighted.

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