The Seaver Lab published a February 2026 paper entitled “Regrowing the growth zone: metamorphosis kickstarts regeneration in the annelid Capitella teleta” in the journal Development. Their paper was also featured by the journal as a research highlight and interview with authors Alicia Boyd and Elaine Seaver.
PAPER ABSTRACT
The ability to regenerate can vary across the life history of an animal. We previously showed that Capitella teleta, an annelid worm, gains regenerative ability with age. Although larvae do not replace lost structures, juveniles and adults regenerate posteriorly following metamorphosis. To determine whether metamorphosis enables juveniles to regrow structures lost as larvae, we amputated C. teleta larvae, removing posterior segments, hindgut, posterior growth zone, anus and pygidium. Metamorphosis was then induced in these amputated larvae and they were reared as juveniles for 3, 7 or 14 days. New growth in juveniles was assessed by confocal microscopy, 5-ethynyl-2′-deoxyuridine incorporation, immunohistochemistry and nuclear staining. A posterior growth zone and new segments were observed by 7 days post-metamorphosis. Remodeling of the digestive system in pre-existing tissue was also observed. Additionally, re-amputation of juveniles resulted in regeneration of the posterior growth zone, segments and hindgut. Our results demonstrate that amputated C. teleta larvae can metamorphose into functional juveniles capable of growing new segments, suggesting that metamorphosis acts as a switch to enable regeneration of structures essential for growth. This study highlights the impact of metamorphosis on changes in developmental plasticity.
The full paper can be found at the following link.
RESEARCH HIGHLIGHT
Regeneration and metamorphosis represent two post-embryonic developmental processes. In mammals, regeneration abilities appear to decrease after development and with the onset of maturation and ageing. Similarly, in some amphibians, regeneration competency is significantly reduced or entirely lost following metamorphosis. Interestingly, previous work showed that Capitella teleta, an annelid worm, gains regenerative ability with age. Here, Elaine Seaver and Alicia Boyd investigate the onset of regenerative capacity following metamorphosis in C. teleta. Together, this study reveals that regeneration can be temporally separated from wound-related triggers as amputated C. teleta larvae regain their lost structures only after metamorphosing into functional juveniles, indicating that metamorphosis might serve as a switch in the annelid regenerative potential.
The full article can be found at the following link.
THE PEOPLE BEHIND THE PAPERS
While in most animals, regeneration abilities decrease after development and with the onset of maturation and ageing, Capitella teleta, an annelid worm, gains regenerative ability with age. In their work, Elaine Seaver and Alicia Boyd show that metamorphosis might serve as a switch in annelid regenerative potential. To learn about their work, we spoke to the first author, Alicia Boyd, and the corresponding author, Elaine Seaver, Professor of Biology, Whitney Laboratory for Marine Bioscience, University of Florida, USA.
The interview can be found at the following link.