Abstract
BackgroundIntercalary pattern formation is an important regulatory step in amphibian limb regeneration. Amphibian limb regeneration is composed of multiple steps, including wounding, blastema formation, and intercalary pattern formation. Attempts have been made to transfer insights from regeneration-competent animals to regeneration-incompetent animalsat each step in the regeneration process. In the present study, we focused on the intercalary mechanism in chick limb buds. In amphibian limb regeneration, a proximodistal axis is organized as soon as a regenerating blastema is induced. Intermediate structures are subsequently induced (intercalated) between the established proximal and distal identities. Intercalary tissues are derived from proximal tissues. Fgf signaling mediates the intercalary response in amphibian limb regeneration.ResultsWe attempted to transfer insights into intercalary regeneration from amphibian models to the chick limb bud. The zeugopodial part was dissected out, and the distal and proximal parts were conjunct at st. 24. Delivering ectopic Fgf2 + Fgf8 between the distal and proximal parts resulted in induction of zeugopodial elements. Examination of HoxA11 expression, apoptosis, and cell proliferation provides insights to compare with those in the intercalary mechanism of amphibian limb regeneration. Furthermore, the cellular contribution was investigated in both the chicken intercalary response and that of axolotl limb regeneration.ConclusionsWe developed new insights into cellular contribution in amphibian intercalary regeneration, and found consistency between axolotl and chicken intercalary responses. Our findings demonstrate that the same principal of limb regeneration functions between regeneration-competent and -incompetent animals. In this context, we propose the feasibility of the induction of the regeneration response in amniotes.
Highlights
Intercalary pattern formation is an important regulatory step in amphibian limb regeneration
We found that ectopic Fgf2 + 8 application resulted in induction of the zeugopodial elements
Green fluorescent protein (GFP) transgenic axolotls were obtained from the Ambystoma Genetic Stock Center (AGSC)
Summary
Intercalary pattern formation is an important regulatory step in amphibian limb regeneration. Amphibian limb regeneration is composed of multiple steps, including wounding, blastema formation, and intercalary pattern formation. Intermediate structures are subsequently induced (intercalated) between the established proximal and distal identities. Blastema formation is considered to be the primary issue, since regeneration-incompetent animals, such as amniotes, do not form a blastema after damage. Regeneration blastemas are thought to have a similar structure as developing limb buds. A regeneration blastema and an amputated plane initially re-establish a distal and a proximal positional identity, respectively [6,7,8]. Intermediate structures are induced between the distal and the proximal tissues This induction of an intermediate region by an established distal and an amputated stump is called “intercalation.” These intercalary pattern-
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
