Eugene Bell Center for Regenerative Biology and Tissue Engineering
Permanent URI for this community
The ability of many animals to spontaneously regenerate their body parts has intrigued scientific observers for centuries. Although humans share the same basic genes and pathways, we have somehow lost these regenerative capacities, which leads to significant health costs. An understanding of tissue and organ regeneration in lower animals holds great promise for translating to medical treatments for serious human conditions, including spinal cord injury, diabetes, organ failure, and degenerative neural diseases such as Alzheimer’s.
Browse
Browsing Eugene Bell Center for Regenerative Biology and Tissue Engineering by Subject "Xenopus laevis"
Results Per Page
Sort Options
-
ArticleExpanding the genetic toolkit in Xenopus : approaches and opportunities for human disease modeling(Elsevier, 2016-04-22) Tandon, Panna ; Conlon, Frank ; Furlow, J. David ; Horb, Marko E.The amphibian model Xenopus, has been used extensively over the past century to study multiple aspects of cell and developmental biology. Xenopus offers advantages of a non-mammalian system, including high fecundity, external development, and simple housing requirements, with additional advantages of large embryos, highly conserved developmental processes, and close evolutionary relationship to higher vertebrates. There are two main species of Xenopus used in biomedical research, Xenopus laevis and Xenopus tropicalis; the common perception is that both species are excellent models for embryological and cell biological studies, but only Xenopus tropicalis is useful as a genetic model. The recent completion of the Xenopus laevis genome sequence combined with implementation of genome editing tools, such as TALENs (transcription activator-like effector nucleases) and CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated nucleases), greatly facilitates the use of both Xenopus laevis and Xenopus tropicalis for understanding gene function in development and disease. In this paper, we review recent advances made in Xenopus laevis and Xenopus tropicalis with TALENs and CRISPR-Cas and discuss the various approaches that have been used to generate knockout and knock-in animals in both species. These advances show that both Xenopus species are useful for genetic approaches and in particular counters the notion that Xenopus laevis is not amenable to genetic manipulations.
-
ArticleGeneration of a Xenopus laevis F1 albino J strain by genome editing and oocyte host-transfer(Elsevier, 2016-03-15) Ratzan, Wil ; Falco, Rosalia ; Salanga, Cristy ; Salanga, Matthew C. ; Horb, Marko E.Completion of the Xenopus laevis genome sequence from inbred J strain animals has facilitated the generation of germline mutant X. laevis using targeted genome editing. In the last few years, numerous reports have demonstrated that TALENs are able to induce mutations in F0 Xenopus embryos, but none has demonstrated germline transmission of such mutations in X. laevis. In this report we used the oocyte host-transfer method to generate mutations in both tyrosinase homeologs and found highly-penetrant germline mutations; in contrast, embryonic injections yielded few germline mutations. We also compared the distribution of mutations in several F0 somatic tissues and germ cells and found that the majority of mutations in each tissue were different. These results establish that X. laevis J strain animals are very useful for generating germline mutations and that the oocyte host-transfer method is an efficient technique for generating mutations in both homeologs.
-
ArticleLuteinizing Hormone is an effective replacement for hCG to induce ovulation in Xenopus(Elsevier, 2016-06-02) Wlizla, Marcin ; Falco, Rosalia ; Peshkin, Leonid ; Parlow, Albert F. ; Horb, Marko E.Injection of human Chorionic Gonadotropin (hCG) directly into the dorsal lymph sac of Xenopus is a commonly used protocol for induction of ovulation, but recent shortages in the stocks of commercially available hCG as well as lack of a well tested alternative have resulted in frustrating experimental delays in laboratories that predominantly use Xenopus in their research. Mammalian Luteinizing Hormones (LH) share structural similarity, functional equivalency, and bind the same receptor as hCG; this suggests that LH may serve as a good alternative to hCG for promoting ovulation in Xenopus. LH has been found to induce maturation of Xenopus oocytes in vitro, but whether it can be used to induce ovulation in vivo has not been examined. Here we compared the ability of four mammalian LH proteins, bovine (bLH), human (hLH), ovine (oLH), porcine (pLH), to induce ovulation in Xenopus when injected into the dorsal lymph sac of sexually mature females. We find that both ovine and human LH, but not bovine or porcine, are good substitutes for hCG for induction of ovulation in WT and J strain Xenopus laevis and Xenopus tropicalis.
-
ArticleNormal table of Xenopus development: a new graphical resource(The Company of Biologists, 2022-07-14) Zahn, Natalya ; James-Zorn, Christina ; Ponferrada, Virgilio G. ; Adams, Dany S. ; Grzymkowski, Julia ; Buchholz, Daniel R. ; Nascone-Yoder, Nanette M. ; Horb, Marko E. ; Moody, Sally A. ; Vize, Peter D. ; Zorn, Aaron M.Normal tables of development are essential for studies of embryogenesis, serving as an important resource for model organisms, including the frog Xenopus laevis. Xenopus has long been used to study developmental and cell biology, and is an increasingly important model for human birth defects and disease, genomics, proteomics and toxicology. Scientists utilize Nieuwkoop and Faber's classic ‘Normal Table of Xenopus laevis (Daudin)’ and accompanying illustrations to enable experimental reproducibility and reuse the illustrations in new publications and teaching. However, it is no longer possible to obtain permission for these copyrighted illustrations. We present 133 new, high-quality illustrations of X. laevis development from fertilization to metamorphosis, with additional views that were not available in the original collection. All the images are available on Xenbase, the Xenopus knowledgebase (http://www.xenbase.org/entry/zahn.do), for download and reuse under an attributable, non-commercial creative commons license. Additionally, we have compiled a ‘Landmarks Table’ of key morphological features and marker gene expression that can be used to distinguish stages quickly and reliably (https://www.xenbase.org/entry/landmarks-table.do). This new open-access resource will facilitate Xenopus research and teaching in the decades to come.
-
ArticleXenopus resources: Transgenic, inbred and mutant animals, training opportunities, and web-based support.(Frontiers Media, 2019-04-25) Horb, Marko E. ; Wlizla, Marcin ; Abu-Daya, Anita ; McNamara, Sean ; Gajdasik, Dominika ; Igawa, Takeshi ; Suzuki, Atsushi ; Ogino, Hajime ; Noble, Anna ; Robert, Jacques ; James-Zorn, Christina ; Guille, Matthew ; Nicolas, Morgane ; Lafond, Thomas ; Boujard, Daniel ; Audic, Yann ; Guillet, Brigitte ; Centre de Ressource Biologique Xenope team in FranceTwo species of the clawed frog family, Xenopus laevis and X. tropicalis, are widely used as tools to investigate both normal and disease-state biochemistry, genetics, cell biology, and developmental biology. To support both frog specialist and non-specialist scientists needing access to these models for their research, a number of centralized resources exist around the world. These include centers that hold live and frozen stocks of transgenic, inbred and mutant animals and centers that hold molecular resources. This infrastructure is supported by a model organism database. Here, we describe much of this infrastructure and encourage the community to make the best use of it and to guide the resource centers in developing new lines and libraries.