TY  - JOUR
AU  - Franke, Maximilian
AU  - Geier, Benedikt
AU  - Hammel, Jörg U.
AU  - Dubilier, Nicole
AU  - Leisch, Nikolaus
TI  - Coming together—symbiont acquisition and early development in deep-sea bathymodioline mussels
JO  - Proceedings of the Royal Society of London / B
VL  - 288
IS  - 1957
SN  - 0962-8452
CY  - London
PB  - Royal Soc. of London
M1  - PUBDB-2021-03658
SP  - 20211044
PY  - 2021
AB  - How and when symbionts are acquired by their animal hosts has a profound impact on the ecology and evolution of the symbiosis. Understanding symbiont acquisition is particularly challenging in deep-sea organisms because early life stages are so rarely found. Here, we collected early developmental stages of three deep-sea bathymodioline species from different habitats to identify when these acquire their symbionts and how their body plan adapts to a symbiotic lifestyle. These mussels gain their nutrition from chemosynthetic bacteria, allowing them to thrive at deep-sea vents and seeps worldwide. Correlative imaging analyses using synchrotron-radiation based microtomography together with light, fluorescence and electron microscopy revealed that the pediveliger larvae were aposymbiotic. Symbiont colonization began during metamorphosis from a planktonic to a benthic lifestyle, with the symbionts rapidly colonizing first the gills, the symbiotic organ of adults, followed by all other epithelia of their hosts. Once symbiont densities in plantigrades reached those of adults, the host's intestine changed from the looped anatomy typical for bivalves to a straightened form. Within the Mytilidae, this morphological change appears to be specific to Bathymodiolus and Gigantidas, and is probably linked to the decrease in the importance of filter feeding when these mussels switch to gaining their nutrition largely from their symbionts. 
LB  - PUB:(DE-HGF)16
C6  - pmid:34403628
UR  - <Go to ISI:>//WOS:000687673400008
DO  - DOI:10.1098/rspb.2021.1044
UR  - https://bib-pubdb1.desy.de/record/463157
ER  -