Symbiosis

, Volume 63, Issue 1, pp 19–29

Comparative analysis of symbiont ratios and gene expression in natural populations of two Bathymodiolus mussel species

  • H. Guezi
  • I. Boutet
  • A. C. Andersen
  • F. H. Lallier
  • A. Tanguy
Article

DOI: 10.1007/s13199-014-0284-0

Cite this article as:
Guezi, H., Boutet, I., Andersen, A.C. et al. Symbiosis (2014) 63: 19. doi:10.1007/s13199-014-0284-0

Abstract

Bathymodiolus mussels associated with deep-sea hydrothermal vents and cold seeps harbor chemosynthetic endosymbiotic bacteria in bacteriocytes located in the gill epithelium. Two distinct morphotypes of γ-proteobacteria, sulfur- and methane-oxidizing, have been identified and form a dual symbiosis in B. azoricus mussels from the Mid-Atlantic Ridge and in B. aff. boomerang from cold seeps in the Gulf of Guinea. Thiotrophic bacteria (SOX) are capable of fixing CO2 in the presence of sulfide or thiosulfate and methanotrophic bacteria (MOX) use methane both as a carbon and an energy source. In this study we used quantitative real-time PCR to test whether symbiont abundance and gene expression varied between the two mussel species. Results showed that B. azoricus from two hydrothermal sites had similar ratios and gene expression pattern for both symbiont types. In B. aff. boomerang, SOX ratio and ATP sulfurylase gene expression show differences between specimens collected on the different sites. Analysis of symbiont ratios in both species indicated a clear dominance of MOX symbionts in B. aff. boomerang and SOX symbionts in B. azoricus. We also evidenced that the species from the deeper sites (B. aff. boomerang) and mussels collected from sulfur and methane rich habitats showed higher symbiont ratio suggesting that environmental parameters may have significant impacts on the symbiont ratios in Bathymodiolus mussels.

Keywords

Hydrothermal ventCold seepsBathymodiolusSymbiontFish

Abbreviations

DAPI

4’,6-DiAmidino-2-Phenyl-Indole double-stranded DNA staining

Cy3 and Cy5

Cyanine dyes

FISH

Fluorescencent In Situ Hybridization

MOX

Methane OXidizing bacteria

pmoA

particulate methane oxygenase subunit A

ROV

Remotely Operated Vehicle

SOX

Sulfur OXidizing bacteria

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  • H. Guezi
    • 1
    • 2
  • I. Boutet
    • 1
    • 2
  • A. C. Andersen
    • 1
    • 2
  • F. H. Lallier
    • 1
    • 2
  • A. Tanguy
    • 1
    • 2
  1. 1.CNRS, UMR 7144, Adaptation et Diversité en Milieu MarinRoscoffFrance
  2. 2.Sorbonne UniversitésRoscoffFrance