Regeneration in the metazoans: why does it happen?

Area of Science:

• Developmental Biology
• Evolutionary Biology
• Zoology

Background:

• Animal regeneration, the ability of an organism to regrow tissues or organs, is a widespread yet incompletely understood phenomenon.
• Despite over 250 years of research, the mechanistic basis and evolutionary drivers of regeneration remain elusive.
• Key questions concern the differential distribution of regeneration capabilities across metazoan phyla and the factors influencing its occurrence.

Purpose of the Study:

• To review the distribution and modes of regeneration across metazoan phyla.
• To re-examine the evolutionary origins of regeneration.
• To propose a comparative experimental approach for understanding the molecular basis of regeneration.

Main Methods:

• Literature review of regeneration studies across diverse metazoan groups.
• Analysis of evolutionary developmental biology (evo-devo) principles related to regeneration.
• Conceptual framework for a comparative experimental strategy.

Main Results:

• Regeneration varies significantly across metazoan phyla, suggesting diverse underlying mechanisms and evolutionary paths.
• Potential links between regeneration, asexual reproduction, and embryogenesis are explored.
• An integrated interpretation of regeneration considering both evolutionary and developmental aspects is presented.

Conclusions:

• Understanding animal regeneration requires integrating evolutionary and developmental perspectives.
• A comparative experimental approach is crucial for deciphering the molecular underpinnings of regeneration.
• Further research is needed to answer fundamental questions about why and how regeneration occurs.