Telomere DNA length is a complex trait controlled both by multiple loci
and environmental factors. Even though the use of telomere DNA length
measurement, as a method of assessing stress accumulation and predicting
how this will influence survival, is currently being studied in numerous
human cohort studies, the importance of telomere length for stress
response in ecological studies remains at its infancy. Here, we
investigated the telomere changes occurring in the symbiotic coral
Stylophora pistillata that has experienced a continuous darkness over
six months. This stress condition led to the loss of its symbionts, as
what is also observed when bleaching occurs in the field at a
large-scale due to climate changes and anthropogenic activities,
threatening the worldwide reef ecosystem. We found that the continuous
darkness condition was associated with telomere DNA length shortening
and a downregulation of the expression of the telomere-associated
protein Pot2. These results pave the way for future studies on the role
of telomere in coral stress response and the importance of telomere
dysregulation in endangered coral species.