Changing perspectives – from ecology to cellular biology in the bathymodioline symbiosis

Abstract

Symbiotic associations are found in all domains of life. However, how the aposymbiotic life stages survive, how the symbiosis is initiated, and how it is maintained over the lifecycle of the holobiont is only known for some model organisms.

In the context of this thesis, these questions were studied in the bathymodioline symbiosis. Bathymodioline mussels successfully live at hydrothermal vents, cold seeps, and organic falls worldwide. Although the system is relatively well known, their symbiont-host association on an ultrastructural level, their early development, their symbiont acquisition as well as their aposymbiotic life is still mostly unknown.

Despite being studied for more than 40 years, only now with the identification of aposymbiotic life stages and the technological advances over the last years we were able to answer fundamental questions regarding the ecology, early development, and cellular biology of this symbiotic system.