Telomere elongation and telomerase expression in regenerating arms of the starfish Luidia clathrata (Asteroidea: Echinodermata)

摘要

Regeneration in echinoderms has been extensively characterized physiologically, but fewer studies have addressed the genetic mechanisms underlying the process. Telomeres, genetic sequences on the ends of chromosomes that shorten with cell division, are associated with cell senescence, and thus genetic age after cell growth. Relative telomere lengths in the starfish Luidia clathrata were measured in arms of juveniles, adults prior to injury, and adults after injury during initial regeneration. Additionally, relative telomerase expression was measured in arms of adults prior to injury, at wound closure, and during initial regeneration. Telomeres were longer in juveniles than uninjured adults, indicating genetic aging. Telomeres elongated in adults after injury. Telomerase was detected before and after injury. The combination of genetic aging and telomerase expression both before and after injury suggests possible post-transcriptional regulation of telomerase. Additionally, as previous studies did not detect elongated telomeres in regenerated arms, it is possible that telomere elongation occurs early in the regenerative process as a mechanism to permit cellular division for growth without aging the final regenerated arm.