211
rithm was then applied to individual networks of BGCs
belonging to different classes of enzymes (i.e., terpeneproducers) to further understand the relatedness and novelty of BGCs in the world’s oceans.
5.2.6 Marine Sponge Symbionts: United
in Defense But Specialized in Metabolism
Beate M. Slaby
1,2*
, Thomas Hackl
3
, Hannes Horn
1,2
, Kristina
Bayer
1
, Ute Hentschel
1,4
1
RD3 Marine Microbiology, GEOMAR Helmholtz Centre
for Ocean Research Kiel, Germany
2
Dept. of Botany II, Julius-von-Sachs Institute for
Biological Science, University of Würzburg, Germany
3
Dept. of Civil and Environmental Engineering,
Massachusetts Institute of Technology, Cambridge, MA,
USA
4
Christian-Albrechts University of Kiel, Germany
*corresponding author: bslaby@geomar.de
Keywords: Metagenomics, PacBio, Illumina HiSeq,
Hybrid assembly, Differential coverage binning
Marine sponges are ancient metazoans that are populated
by distinct and highly diverse microbial communities. In
order to obtain deeper insights into the functional gene repertoire of the Mediterranean sponge Aplysina aerophoba,
we combined Illumina short-read and PacBio long-read
sequencing followed by un-targeted metagenomic binning
(Slaby et al., ISME J in press). We identified a total of 37
high- quality bins from 11 bacterial phyla and 2 candidate
phyla, which are representative of the sponge symbiont consortium known from previous studies. For comparison to
closely related bacteria from non-sponge environments, we
selected reference genomes based on genome completeness,
phylogenetic similarity, and habitat (marine preferred over
other habitats). Statistical group-wise comparison of symbiont and reference genomes by Welch’s t-test based on clusters of orthologous groups (COGs) revealed a significant
enrichment of genes related to bacterial defense (restrictionmodification systems, toxin-antitoxin systems) as well as
genes involved in host colonization and extracellular matrix
utilization in sponge symbionts. A within-symbionts
genome comparison by principle component analysis (PCA)
revealed a nutritional specialization of at least two symbiont
guilds, where one appears to metabolize carnitine and the
other sulfated polysaccharides, both of which are abundant
molecules in the sponge extracellular matrix. A third guild
of symbionts may be viewed as nutritional generalists that
perform largely the same metabolic pathways but lack such
extraordinary numbers of the relevant genes. This study
characterizes the genomic repertoire of sponge symbionts at
an unprecedented resolution and it provides greater insights
into the molecular mechanisms underlying microbialsponge symbiosis.
5.2.7 Investigating Transcriptome and Proteome
Heat Stress Response of the Cnidarian Model
Organism Exaiptasia pallida
Maha J. Cziesielski
1
*, Yi Jin Liew
1
, Sebastian SchmidtRoach
1
, Guoxin Cui
1
, Sara Campana
1
, Claudius Marondedze
2
,
Manuel Aranda
1*
1
King Abdullah University of Science and Technology
(KAUST), Red Sea Research Center (RSRC), Biological and
Environmental Sciences & Engineering Division (BESE),
Thuwal, Saudi Arabia
2
Cambridge Center for Proteomics, Department of
Biochemistry, University of Cambridge, Cambridge, United
Kingdom
*corresponding authors: maha.olschowsky@kaust.edu.
sa, manuel.aranda@kaust.edu.sa
Keywords: Transcriptomics, Proteomics, Heat stress,
Exaiptasia, Biomarkers
Corals, and their endosymbiotic dinoflagellates of the
genus Symbiodinium, are key building blocks of the coral
reef ecosystem. This symbiotic relationship is fragile and
breaks down under heat stress, which leads to bleaching of
the corals. Transcriptomic approaches to investigate potential mechanisms of acclimatization and adaptation have
become increasingly popular with growing application of
next generation sequencing (NGS) technology, in particular
RNA- Seq. While significant information regarding coral
and larvae stress response has been obtained on a transcriptomic level, proteomics has remained mostly unaddressed.
Proteins ultimately dictate fitness, but studies on other
model organisms (i.e., mice and humans) have continuously
reported low correlations between mRNA and protein.
Using the small anemone Exaiptasia pallida, we investigated transcriptome- and proteome-wide heat stress
responses in a cnidarian. Anemones from North Carolina
(CC7), Hawaii (H2) and the Red Sea (RS) were heat stressed
for 24 h. Comparison across genotype transcriptomes
showed a number of shared pathways previously suggested
to represent a core cnidarian thermal stress response, however little commonality was observed on a proteomic basis.
We report consistently low correlation between mRNA and
protein, which reduced further when focusing on fold
changes. In order to assess the heat stress response capacity
of the genotypes, we tested previously suggested biomarkers. Using the multi-omics data obtained, we further investigated the stability of these biomarkers across layers and
strains. We managed to validate 12 biomarkers and suggest
new ones to be considered based on their transcriptomic
consistency. We suggest important parameters to be kept
under consideration during biomarker development and
inter-strain response comparisons. Overall, our study highlights core cnidarian heat stress mechanisms and the importance of inter-disciplinary omics approaches.
Appendices
rithm was then applied to individual networks of BGCs
belonging to different classes of enzymes (i.e., terpeneproducers) to further understand the relatedness and novelty of BGCs in the world’s oceans.
5.2.6 Marine Sponge Symbionts: United
in Defense But Specialized in Metabolism
Beate M. Slaby
1,2*
, Thomas Hackl
3
, Hannes Horn
1,2
, Kristina
Bayer
1
, Ute Hentschel
1,4
1
RD3 Marine Microbiology, GEOMAR Helmholtz Centre
for Ocean Research Kiel, Germany
2
Dept. of Botany II, Julius-von-Sachs Institute for
Biological Science, University of Würzburg, Germany
3
Dept. of Civil and Environmental Engineering,
Massachusetts Institute of Technology, Cambridge, MA,
USA
4
Christian-Albrechts University of Kiel, Germany
*corresponding author: bslaby@geomar.de
Keywords: Metagenomics, PacBio, Illumina HiSeq,
Hybrid assembly, Differential coverage binning
Marine sponges are ancient metazoans that are populated
by distinct and highly diverse microbial communities. In
order to obtain deeper insights into the functional gene repertoire of the Mediterranean sponge Aplysina aerophoba,
we combined Illumina short-read and PacBio long-read
sequencing followed by un-targeted metagenomic binning
(Slaby et al., ISME J in press). We identified a total of 37
high- quality bins from 11 bacterial phyla and 2 candidate
phyla, which are representative of the sponge symbiont consortium known from previous studies. For comparison to
closely related bacteria from non-sponge environments, we
selected reference genomes based on genome completeness,
phylogenetic similarity, and habitat (marine preferred over
other habitats). Statistical group-wise comparison of symbiont and reference genomes by Welch’s t-test based on clusters of orthologous groups (COGs) revealed a significant
enrichment of genes related to bacterial defense (restrictionmodification systems, toxin-antitoxin systems) as well as
genes involved in host colonization and extracellular matrix
utilization in sponge symbionts. A within-symbionts
genome comparison by principle component analysis (PCA)
revealed a nutritional specialization of at least two symbiont
guilds, where one appears to metabolize carnitine and the
other sulfated polysaccharides, both of which are abundant
molecules in the sponge extracellular matrix. A third guild
of symbionts may be viewed as nutritional generalists that
perform largely the same metabolic pathways but lack such
extraordinary numbers of the relevant genes. This study
characterizes the genomic repertoire of sponge symbionts at
an unprecedented resolution and it provides greater insights
into the molecular mechanisms underlying microbialsponge symbiosis.
5.2.7 Investigating Transcriptome and Proteome
Heat Stress Response of the Cnidarian Model
Organism Exaiptasia pallida
Maha J. Cziesielski
1
*, Yi Jin Liew
1
, Sebastian SchmidtRoach
1
, Guoxin Cui
1
, Sara Campana
1
, Claudius Marondedze
2
,
Manuel Aranda
1*
1
King Abdullah University of Science and Technology
(KAUST), Red Sea Research Center (RSRC), Biological and
Environmental Sciences & Engineering Division (BESE),
Thuwal, Saudi Arabia
2
Cambridge Center for Proteomics, Department of
Biochemistry, University of Cambridge, Cambridge, United
Kingdom
*corresponding authors: maha.olschowsky@kaust.edu.
sa, manuel.aranda@kaust.edu.sa
Keywords: Transcriptomics, Proteomics, Heat stress,
Exaiptasia, Biomarkers
Corals, and their endosymbiotic dinoflagellates of the
genus Symbiodinium, are key building blocks of the coral
reef ecosystem. This symbiotic relationship is fragile and
breaks down under heat stress, which leads to bleaching of
the corals. Transcriptomic approaches to investigate potential mechanisms of acclimatization and adaptation have
become increasingly popular with growing application of
next generation sequencing (NGS) technology, in particular
RNA- Seq. While significant information regarding coral
and larvae stress response has been obtained on a transcriptomic level, proteomics has remained mostly unaddressed.
Proteins ultimately dictate fitness, but studies on other
model organisms (i.e., mice and humans) have continuously
reported low correlations between mRNA and protein.
Using the small anemone Exaiptasia pallida, we investigated transcriptome- and proteome-wide heat stress
responses in a cnidarian. Anemones from North Carolina
(CC7), Hawaii (H2) and the Red Sea (RS) were heat stressed
for 24 h. Comparison across genotype transcriptomes
showed a number of shared pathways previously suggested
to represent a core cnidarian thermal stress response, however little commonality was observed on a proteomic basis.
We report consistently low correlation between mRNA and
protein, which reduced further when focusing on fold
changes. In order to assess the heat stress response capacity
of the genotypes, we tested previously suggested biomarkers. Using the multi-omics data obtained, we further investigated the stability of these biomarkers across layers and
strains. We managed to validate 12 biomarkers and suggest
new ones to be considered based on their transcriptomic
consistency. We suggest important parameters to be kept
under consideration during biomarker development and
inter-strain response comparisons. Overall, our study highlights core cnidarian heat stress mechanisms and the importance of inter-disciplinary omics approaches.
Appendices