Project description:The presence of nerves is an important factor in successful organ regeneration in amphibians. The Mexican salamander, Ambystoma mexicanum, is able to regenerate limbs, tail, and gills when nerves are present. However, the nerve-dependency of tooth regeneration has not been evaluated. Here, we reevaluated tooth regeneration processes in axolotls using a three-dimensional reconstitution method called CoMBI and found that tooth regeneration is nerve-dependent although the dentary bone is independent of nerve presence. The induction and invagination of the dental lamina were delayed by denervation. Exogenous Fgf2, Fgf8, and Bmp7 expression could induce tooth placodes even in the denervated mandible. Our results suggest that the role of nerves is conserved and that Fgf+Bmp signals play key roles in axolotl organ-level regeneration. The presence of nerves is an important factor in successful organ regeneration in amphibians. The Mexican salamander, Ambystoma mexicanum, is able to regenerate limbs, tail, and gills when nerves are present. However, the nervedependency of tooth regeneration has not been evaluated. Here, we reevaluated tooth regeneration processes in axolotls using a three-dimensional reconstitution method called CoMBI and found that tooth regeneration is nerve-dependent although the dentary bone is independent of nerve presence. The induction and invagination of the dental lamina were delayed by denervation. Exogenous Fgf2, Fgf8, and Bmp7 expression could induce tooth placodes even in the denervated mandible. Our results suggest that the role of nerves is conserved and that Fgf+Bmp signals play key roles in axolotl organ-level regeneration.

| S-EPMC7283310 | biostudies-literature

Regeneration of limb joints in the axolotl (Ambystoma mexicanum).

Project description:In spite of numerous investigations of regenerating salamander limbs, little attention has been paid to the details of how joints are reformed. An understanding of the process and mechanisms of joint regeneration in this model system for tetrapod limb regeneration would provide insights into developing novel therapies for inducing joint regeneration in humans. To this end, we have used the axolotl (Mexican Salamander) model of limb regeneration to describe the morphology and the expression patterns of marker genes during joint regeneration in response to limb amputation. These data are consistent with the hypothesis that the mechanisms of joint formation whether it be development or regeneration are conserved. We also have determined that defects in the epiphyseal region of both forelimbs and hind limbs in the axolotl are regenerated only when the defect is small. As is the case with defects in the diaphysis, there is a critical size above which the endogenous regenerative response is not sufficient to regenerate the joint. This non-regenerative response in an animal that has the ability to regenerate perfectly provides the opportunity to screen for the signaling pathways to induce regeneration of articular cartilage and joints.

| S-EPMC3503958 | biostudies-literature

MRI- and histologically derived neuroanatomical atlas of the Ambystoma mexicanum (axolotl).

Project description:Amphibians are an important vertebrate model system to understand anatomy, genetics and physiology. Importantly, the brain and spinal cord of adult urodels (salamanders) have an incredible regeneration capacity, contrary to anurans (frogs) and the rest of adult vertebrates. Among these amphibians, the axolotl (Ambystoma mexicanum) has gained most attention because of the surge in the understanding of central nervous system (CNS) regeneration and the recent sequencing of its whole genome. However, a complete comprehension of the brain anatomy is not available. In the present study we created a magnetic resonance imaging (MRI) atlas of the in vivo neuroanatomy of the juvenile axolotl brain. This is the first MRI atlas for this species and includes three levels: (1) 82 regions of interest (ROIs) and a version with 64 ROIs; (2) a division of the brain according to the embryological origin of the neural tube, and (3) left and right hemispheres. Additionally, we localized the myelin rich regions of the juvenile brain. The atlas, the template that the atlas was derived from, and a masking file, can be found on Zenodo at https://doi.org/10.5281/zenodo.4595016 . This MRI brain atlas aims to be an important tool for future research of the axolotl brain and that of other amphibians.

| S-EPMC8110773 | biostudies-literature

Ambystoma mexicanum

Project description:Ambystoma mexicanum Transcriptome or Gene expression

| PRJNA291645 | ENA

Ambystoma mexicanum

Project description:Expression data from aquatic and terrestrial axolotl full thickness epithelial flank wounds collected over seven days

| PRJNA152821 | ENA

Ambystoma mexicanum

Project description:Dynamic membrane depolarization is an early regulator of ependymoglial cell response to spinal cord injury in axolotl

| PRJNA292499 | ENA

Ambystoma mexicanum

Project description:Identification of regenerative roadblocks via repeat deployment of limb regeneration in axolotls