Several repeated DNA sequences were isolated from a partial genomic DNA library of the newt Pleurodeles waltl. These repeated DNA elements are dispersed over the 12 P. waltl bivalents, and some of them are transcribed in the oocyte. We describe the localization of label following in situ hybridization to nascent RNA attached to the lateral loops of lampbrush chromosomes. Variations in the number and the location of labelled loops were constantly found for several of the probes. The results are discussed in view of the "cotranscription model" of RNA synthesis on lampbrush chromosomes. We speculate on the possible origins of variation in transcription on lampbrush loops.
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http://dx.doi.org/10.1111/j.1768-322x.1989.tb03005.x | DOI Listing |
Cell Genom
January 2025
Department of Cell and Molecular Biology, Karolinska Institute, 171 65 Stockholm, Sweden. Electronic address:
Newts have large genomes harboring many repeat elements. How these elements shape the genome and relate to newts' unique regeneration ability remains unknown. We present here the chromosome-scale assembly of the 20.
View Article and Find Full Text PDFCurr Biol
January 2025
Department of Biological Sciences, Columbia University, New York, NY 10027, USA. Electronic address:
Matheson et al. introduce the Iberian ribbed newt (Pleurodeles waltl), a species of salamander that lives some of its adult life on land and some in water, requiring remarkable physiological and behavioral plasticity to adapt to these very different environments.
View Article and Find Full Text PDFDev Dyn
January 2025
Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan.
Background: The pancreas exhibits diverse structures and roles across vertebrates. The pancreas has evolved to include both endocrine and exocrine cells, a change that occurred during the transition from fish to amphibian. This event emphasizes the evolutionary significance of amphibians.
View Article and Find Full Text PDFDev Cell
November 2024
Institute of Science and Technology Austria, Klosterneuburg, Austria. Electronic address:
Amphibians, by virtue of their phylogenetic position, provide invaluable insights on nervous system evolution, development, and remodeling. The genetic toolkit for amphibians, however, remains limited. Recombinant adeno-associated viral vectors (AAVs) are a powerful alternative to transgenesis for labeling and manipulating neurons.
View Article and Find Full Text PDFYonago Acta Med
August 2024
Advanced Medicine & Translational Research Center, Organization for Research Initiative and Promotion, Tottori University, Yonago 683-8503, Japan.
Background: The 3Rs (Reduction, Refinement, Replacement) principle is driving the need for alternative methods in animal testing. Despite advancements in in vitro testing, complex systemic toxicity tests still necessitate in vivo approaches. The aim of this study was to develop a developmental toxicity test protocol using the Iberian ribbed newt () as a model organism, integrating AI image analysis for embryo selection to improve test accuracy and reproducibility.
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