Functional genomic signatures of sponge bacteria reveal unique and shared features of symbiosis.
Sponges form close relationships with bacteria, and a remarkable phylogenetic diversity of yet-uncultured bacteria has been identified from sponges using molecular methods. In this study, we use a comparative metagenomic analysis of the bacterial community in the model sponge Cymbastela concentrica and in the surrounding seawater to identify previously unrecognized genomic signatures and functions for sponge bacteria. We observed a surprisingly large number of transposable insertion elements, a feature also observed in other symbiotic bacteria, as well as a set of predicted mechanisms that may defend the sponge community against the introduction of foreign DNA and hence contribute to its genetic resilience. Moreover, several shared metabolic interactions between bacteria and host include vitamin production, nutrient transport and utilization, and redox sensing and response. Finally, an abundance of protein-protein interactions mediated through ankyrin and tetratricopeptide repeat proteins could represent a mechanism for the sponge to discriminate between food and resident bacteria. These data provide new insight into the evolution of symbiotic diversity, microbial metabolism and host-microbe interactions in sponges.
Centre for Marine Bio-Innovation, The University of New South Wales, Sydney, Australia. t.thomas@unsw.edu.au
Torsten
T
Thomas
Doug
D
Rusch
Matt Z
MZ
DeMaere
Pui Yi
PY
Yung
Matt
M
Lewis
Aaron
A
Halpern
Karla B
KB
Heidelberg
Suhelen
S
Egan
Peter D
PD
Steinberg
Staffan
S
Kjelleberg
D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D005075:Biological Evolution; D055028:Comparative Genomic Hybridization; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D017753:Ecosystem; D016680:Genome, Bacterial; D054892:Metagenome; D010802:Phylogeny; D011161:Porifera / Q000382:microbiology* / Q000502:physiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013559:Symbiosis
D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S