Telomere dynamics in maturing frogs vary among organs.

Area of Science:

• Gerontology
• Developmental Biology
• Comparative Physiology

Background:

• Understanding organ-specific aging is crucial for insights into aging causes.
• Data on organ-specific telomere dynamics, particularly across an organism's lifespan, are limited.
• Previous research in *Xenopus laevis* showed early life telomere changes in gut cells but not liver, heart, or muscle.

Purpose of the Study:

• To investigate organ-specific telomere dynamics from juvenile to adult stages in *Xenopus laevis*.
• To determine the influence of early life temperature on telomere length throughout development.
• To examine sex-specific effects on organ telomere lengths in mature adults.

Main Methods:

• Longitudinal study of *Xenopus laevis* from 70-day post-metamorphic juveniles to 2-year-old adults.
• Analysis of telomere length dynamics in gut, liver, heart, and hindlimb muscle tissues.
• Assessment of effects from different larval rearing temperatures and sex.

Main Results:

• Telomere shortening occurred between juvenile and adult stages in gut, heart, and hindlimb muscle.
• Liver telomere length remained stable with age but was shorter in individuals reared at warmer temperatures.
• Warmer larval temperatures correlated with longer juvenile gut telomeres, and sex influenced organ telomere lengths in adults.

Conclusions:

• Organ-specific aging rates exist, with distinct patterns of telomere dynamics across the lifespan.
• Early developmental conditions (temperature) can influence later life telomere dynamics and organ aging.
• Telomere loss occurs in different organs during post-metamorphic development compared to early life stages.