Scallop-bacteria symbiosis from the deep sea reveals strong genomic coupling in the absence of cellular integration.

Previous studies have revealed tight metabolic complementarity between bivalves and their endosymbiotic chemosynthetic bacteria, but little is known about their interactions with ectosymbionts. Our analysis of the ectosymbiosis between a deep-sea scallop (Catillopecten margaritatus) and a gammaproteobacterium showed that bivalves could be highly interdependent with their ectosymbionts as well. Our microscopic observation revealed abundant sulfur-oxidizing bacteria (SOB) on the surfaces of the gill epithelial cells. Microbial 16S rRNA gene amplicon sequencing of the gill tissues showed the dominance of the SOB. An analysis of the SOB genome showed that it is substantially smaller than its free-living relatives and has lost cellular components required for free-living. Genomic and transcriptomic analyses showed that this ectosymbiont relies on rhodanese-like proteins and SOX multienzyme complex for energy generation, mainly on the Calvin-Benson-Bassham (CBB) cycle and peripherally on a phosphoenolpyruvate carboxylase for carbon assimilation. Besides, the symbiont encodes an incomplete tricarboxylic acid (TCA) cycle. Observation of the scallop's digestive gland and its nitrogen metabolism pathways indicates it does not fully rely on the ectosymbiont for nutrition. Analysis of the host's gene expression provided evidence that it could offer intermediates for the ectosymbiont to complete its TCA cycle and some amino acid synthesis pathways using exosomes, and its phagosomes, endosomes, and lysosomes might be involved in harvesting nutrients from the symbionts. Overall, our study prompts us to rethink the intimacy between the hosts and ectosymbionts in Bivalvia and the evolution of chemosymbiosis in general.

Preoperative small pulmonary nodule localisation using hookwires or coils: strategy selection in adverse events.

OBJECTIVE: This is a retrospective study of adverse events associated with preoperative computed tomography (CT)-guided hookwire or coil localisation. We analysed the experience and process flaws in resecting ground-glass nodules (GGNs) through video-assisted thoracoscopic surgery (VATS) and determined the remedial strategy. METHODS: Adverse events were evaluated in 40 patients with 45 GGNs who underwent CT-guided hookwire or coil localisation before VATS. For lesions not successfully marked or detected, palpation, resection of the highly suspected area, segmentectomy or lobectomy was performed. RESULTS: Among all adverse events, 15 were dislodgement of the marking materials, 5 were breakaway of the marking materials, 7 were > 2 cm distance between the lesions and the tips, 3 was marking material across the two adjacent lobes, 15 were pneumothorax and 2 were certain parts of marking materials stuck into the chest wall. All GGNs were resected successfully. 20 lesions were detected by palpation. 9 GGNs were discovered after the resection of highly suspected areas. Segmentectomies and lobectomies were performed directly on 7 and 9 GGNs, respectively. CONCLUSIONS: When adverse events occur, a second intraoperative localisation, by resecting the highly suspected area either through non-anatomical resection (wedge resection) or anatomical resection (segmentectomy or lobectomy) using the VATS should be considered the alternatives for GGNs localization.

Early genome erosion and internal phage-symbiont-host interaction in the endosymbionts of a cold-seep tubeworm.

Endosymbiosis with chemosynthetic Gammaproteobacteria is widely recognized as an adaptive mechanism of siboglinid tubeworms, yet evolution of these endosymbionts and their driving forces remain elusive. Here, we report a finished endosymbiont genome (HMS1) of the cold-seep tubeworm Sclerolinum annulatum. The HMS1 genome is small in size, with abundant prophages and transposable elements but lacking gene sets coding for denitrification, hydrogen oxidization, oxidative phosphorylation, vitamin biosynthesis, cell pH and/or sodium homeostasis, environmental sensing, and motility, indicative of early genome erosion and adaptive evolution toward obligate endosymbiosis. Unexpectedly, a prophage embedded in the HMS1 genome undergoes lytic cycle. Highly expressed ROS scavenger and LexA repressor genes indicate that the tubeworm host likely activates the lysogenic phage into lytic cycle through the SOS response to regulate endosymbiont population and harvest nutrients. Our findings indicate progressive evolution of Sclerolinum endosymbionts toward obligate endosymbiosis and expand the knowledge about phage-symbiont-host interaction in deep-sea tubeworms.

Metabolomics for in situ monitoring of attached Crassostrea gigas and Mytilus edulis: Effects of offshore wind farms on aquatic organisms.

While offshore wind power has support from countries around the world, studies show that offshore wind farms (OWFs) may affect marine organisms. Environmental metabolomics is a high-throughput method that provides a snapshot of an organism's metabolic state. To elucidate the effects of OWFs on aquatic organisms, we studied, in situ, Crassostrea gigas and Mytilus edulis attached within and outside of OWFs and their reef areas. Our results show that epinephrine, sulphaniline, and inosine 5'-monophosphate were significantly increased and L-carnitine was significantly reduced in both Crassostrea and Mytilus species from the OWFs. This may be related to immune response, oxidative stress, energy metabolism and osmotic pressure regulation of aquatic organisms. Our study shows that active selection of biological monitoring methods for risk assessment is necessary and that metabolomics of attached shellfish is useful in elucidating the metabolic pathways of aquatic organisms in OWFs.

Genome-centric view of the microbiome in a new deep-sea glass sponge species Bathydorus sp.

Sponges are widely distributed in the global ocean and harbor diverse symbiotic microbes with mutualistic relationships. However, sponge symbionts in the deep sea remain poorly studied at the genome level. Here, we report a new glass sponge species of the genus Bathydorus and provide a genome-centric view of its microbiome. We obtained 14 high-quality prokaryotic metagenome-assembled genomes (MAGs) affiliated with the phyla Nitrososphaerota, Pseudomonadota, Nitrospirota, Bdellovibrionota, SAR324, Bacteroidota, and Patescibacteria. In total, 13 of these MAGs probably represent new species, suggesting the high novelty of the deep-sea glass sponge microbiome. An ammonia-oxidizing Nitrososphaerota MAG B01, which accounted for up to 70% of the metagenome reads, dominated the sponge microbiomes. The B01 genome had a highly complex CRISPR array, which likely represents an advantageous evolution toward a symbiotic lifestyle and forceful ability to defend against phages. A sulfur-oxidizing Gammaproteobacteria species was the second most dominant symbiont, and a nitrite-oxidizing Nitrospirota species could also be detected, but with lower relative abundance. Bdellovibrio species represented by two MAGs, B11 and B12, were first reported as potential predatory symbionts in deep-sea glass sponges and have undergone dramatic genome reduction. Comprehensive functional analysis indicated that most of the sponge symbionts encoded CRISPR-Cas systems and eukaryotic-like proteins for symbiotic interactions with the host. Metabolic reconstruction further illustrated their essential roles in carbon, nitrogen, and sulfur cycles. In addition, diverse putative phages were identified from the sponge metagenomes. Our study expands the knowledge of microbial diversity, evolutionary adaption, and metabolic complementarity in deep-sea glass sponges.

A predictive nomogram for lymph node metastasis in part-solid invasive lung adenocarcinoma: A complement to the IASLC novel grading system.

Background: The International Association for the Study of Lung Cancer (IASLC) proposed a novel grading system for invasive lung adenocarcinoma, but lymphatic invasion was not evaluated. Meanwhile, the scope of lymph node dissection in part-solid invasive lung adenocarcinoma (PSILA) is still controversial. Therefore, this study aims to explore preoperative risk factors for lymph node metastasis in PSILA, to provide reference for intraoperative dissection of lymph nodes. Methods: From 2018 to 2020, clinical data of patients (stage cN0) consecutively diagnosed as PSILA were retrospectively analyzed and classified according to the novel grading system. Logistic regression was conducted to screen the clinicopathological factors of lymph node metastasis in PSILA. Results: A large cohort of 960 patients with PSILA who underwent lobectomy or sub-lobectomy were enrolled. By logistic regression analyses, solid part size, bronchial cutoff sign, spiculation, and carbohydrate antigen 199 (CA199) were eventually identified as independent risk factors for lymph node metastasis, based on which a nomogram was built to preoperatively predict the risk of lymph node metastasis [area under the receiver operating characteristic curve (AUC)=0.858; concordance index = 0.857; best cutoff, 0.027]. This suggests that intraoperative systematic lymph node dissection is recommended when the predicted risk value exceeds 0.027. Reproducibility of the novel grading system was verified. Conclusions: The novel IASLC grading system was applicative in real world. The nomogram for preoperative prediction of lymph node metastasis may provide reference for the lymph node dissection strategy during PSILA surgeries.

Surgical Management of 48 Patients with Retrosternal Goiter and Tracheal Stenosis: A Retrospective Clinical Study from a Single Surgical Center.

BACKGROUND Benign retrosternal thyroid goiters can become large enough to compress the trachea and result in tracheomalacia and stenosis. This retrospective study from a single surgical center aimed to study the surgical management of 48 patients with retrosternal goiter and tracheal stenosis diagnosed and treated from January 2017 to December 2021. MATERIAL AND METHODS All preoperative contrast-enhanced CT scans showed retrosternal goiter and tracheal stenosis. RG was classified into type I in 28 patients, type II in 12 patients, and type III in 8 patients. TS was classified into grade I in 31 patients, grade II in 11 patients, and grade III in 6 patients. All patients were referred for surgery. Clinicopathologic features and surgical outcomes were recorded. RESULTS All operations were successfully performed. There were 41 patients with transcervical incision, 4 with cervical incision+sternotomy, 2 with cervical incision and thoracoscopic surgery, and 1 with cervical incision and surgery via the subxiphoid approach. Two patients presented recurrent laryngeal nerve injury. One patient showed short-term hand and foot numbness. The patients were pathologically diagnosed as simple nodular goiter (n=27), nodular goiter combined with cystic change (n=6), adenomatous nodular goiter (n=10), and thyroid adenoma (n=5). There was no prominent tumor recurrence or gradual TS remission. CONCLUSIONS This study has highlighted that patients with retrosternal goiter and tracheal stenosis may have comorbidities and require a multidisciplinary approach to management. The choice of anesthesia, surgical approach, and maintenance of the airway during and after surgery should be individualized.

Carbon metabolism and adaptation of hyperalkaliphilic microbes in serpentinizing spring of Manleluag, the Philippines.

Reduced substrates produced by the serpentinization reaction under hydration of olivine may have fuelled biological processes on early Earth. To understand the adaptive strategies and carbon metabolism of the microbes in the serpentinizing ecosystems, we reconstructed 18 draft genomes representing dominant species of Omnitrophicaeota, Gammaproteobacteria and Methanobacteria from the Manleluag serpentinizing spring in Zambales, Philippines (hyperalkaline and rich in methane and hydrogen). Phylogenomics revealed that two genomes were affiliated with a candidate phylum NPL-UPA2 and the references of all our genomes were derived from ground waters, hot springs and the deep biosphere. C1 metabolism appears to be widespread as most of the genomes code for methanogenesis, CO oxidation and CO2 fixation. However, likely due to the low CO2 concentration and election acceptors, the biomass in the spring was extremely low (<103 cell/ml). Various Na+ and K+ transporters and Na+ -driving ATPases appear to be encoded by these genomes, suggesting that nutrient acquisition, bioenergetics and normal cytoplasmic pH were dependent on Na+ and K+ pumps. Our results advance our understanding of the metabolic potentials and bioenergetics of serpentinizing springs and provide a framework of the ecology of early Earth.

Real-World Effectiveness and Prognostic Factors Analysis of Stages I-III Non-Small Cell Lung Cancer Following Neoadjuvant Chemo-Immunotherapy or Neoadjuvant Chemotherapy.

PURPOSE: Immune checkpoint inhibitors (ICIs) have been successfully used in many clinical trials related to immunotherapy. This study aimed to investigate the clinical efficacy of ICIs and prognostic factors in patients with resectable non-small cell lung cancer (NSCLC) following neoadjuvant therapy in the real world. METHODS: A total of 170 consecutive patients were finally selected and divided into two groups: the preoperative chemotherapy group (n = 91) and the chemo-immunotherapy group (n = 79). The primary endpoint was disease-free survival (DFS). The secondary endpoints were pathological response, clinical response, pathological nodal disease, and ability of multivariate Cox regression analysis to predict survival. Survival was estimated using Kaplan-Meier method and compared using log-rank test. RESULTS: There was a statistically significant difference in DFS between the two groups (log-rank test, P = 0.019). Multivariate Cox regression analysis showed that maximum tumor diameter (P = 0.016), higher lymph node stage (ypN1, P = 0.016; ypN2, P <0.001), and major pathological response not achieved (non-major pathological response [MPR], P = 0.011) were independent prognostic factors for worse DFS. CONCLUSION: Neoadjuvant chemo-immunotherapy yields better effects in pathological and clinical response than chemotherapy alone, which is also associated with longer DFS in the treatment of locally advanced NSCLC. Moreover, a larger tumor specimen diameter, higher ypN staging, and non-MPR after neoadjuvant therapy were associated with worse prognosis.

A novel bacterial phylum that participates in carbon and osmolyte cycling in the Challenger Deep sediments.

Large amounts of detrital organic matter and osmolytes accumulate in the sediments of hadal trenches (>6000 m depth) due to the funnelling effect. It is still unknown whether there are novel active microbes that depend on specific carbon sources in extreme and isolated environments. In this study, we present a novel active bacterial phylum, Candidatus Tianyabacteria in the FCB superphylum, which was enriched in sediments collected from the Challenger Deep. Genome binning resulted in high-quality Ca. Tianyabacteria genomes representing two Ca. Tianyabacteria lineages (L1 and L2) in sediments 0-21 cm below the surface (cmbsf); L1 tends to be abundant in the upper layers (0-9 cmbsf), and L2 seems to be more prevalent in the deeper layers (12-21 cmbsf). Gene annotation and transcriptomics results indicate that the two lineages might import and catalyse amino acids and myo-inositol into central carbon metabolism for a heterotrophic lifestyle. Probably due to differences in environmental oxygen levels, the L2 genomes harbour gene clusters responsible for denitrification and fermentation, while the L1 genomes encode octahaem cytochrome c and multicopper oxidase using unknown substrates. The Ca. Tianyabacteria are thus novel heterotrophic organisms that participate in processes of carbon, nitrogen and organic osmolyte cycling in hadal sediments.

In situ meta-omic insights into the community compositions and ecological roles of hadal microbes in the Mariana Trench.

The low temperature and elevated hydrostatic pressure in hadal trenches at water depths below 6000 m render sample collection difficult. Here, in situ hadal water microbial samples were collected from the Mariana Trench and analysed. The hadal microbial communities at different depths were revealed to be consistent and were dominated by heterotrophic Marinimicrobia. Thirty high-quality metagenome-assembled genomes (MAGs) were retrieved to represent the major hadal microbes affiliated with 12 prokaryotic phyla. Most of the MAGs were newly reported and probably derived from novel hadal inhabitants as exemplified by a potentially new candidate archaeal phylum in the DPANN superphylum. Metabolic reconstruction indicated that a great number of the MAGs participated in nitrogen and sulfur cycling, in which the nitrification process was driven sequentially by Thaumarchaeota and Nitrospirae and sulfur oxidization by Rhodospirillales in the Alphaproteobacteria class. Moreover, several groups of hadal microbes were revealed to be potential carbon monoxide oxidizers. Metatranscriptomic result highlighted the contribution of Chloroflexi in degrading recalcitrant dissolved organic matter and Marinimicrobia in extracellular protein decomposition. The present work provides an in-depth view on the hadal microbial communities regarding their endemism and element cycles.

Spatial variations of microbial communities in abyssal and hadal sediments across the Challenger Deep.

Microbial communities in hadal sediments are least explored in hadal zone (>6,000 m), especially in the Challenger Deep with high pressure (∼110 M pa at the bottom). In this study, we investigated the microbial communities in the sediments of the slope and trench-axis bottom of the Challenger Deep in the Mariana Trench. Classification of the reads of the 16S rRNA gene amplicons showed vertical distribution of prokaryotic microbial inhabitants from the surface to up to 60 centimeter below surface floor (cmbsf). The most dominant phyla were Proteobacteria, Chloroflexi, Actinobacteria, Planctomycetes and candidate phyla Patescibacteria and Marinimicrobia. Distinct dominant groups in the microbial communities were observed in trench-axis sediment (water depth >8,600 m), compared to the slopes of the Challenger Deep. A sampling site at the northern slope was enriched with archaea from mesophilic Euryarchaeota Marine Group II (MGII) as a biomarker of specific geochemical setting. Among archaeal community, Thaumarchaeota represented by Nitrosopumilus were dominant in the upper layers and diminished drastically in the deeper layers. "Ca. Woesearchaeota", however, became the dominant group in the deeper layers. Overall, our study provides a better understanding on the pattern of the microbial communities in the deepest hadal sediments on Earth, and highlights the extraordinary diversity still waiting to be discovered.

Distribution, diversity and functional dissociation of the mac genes in marine biofilms.

Bacteria produce metamorphosis-associated contractile (MAC) structures to induce larval metamorphosis in Hydroides elegans. The distribution and diversity of mac gene homologs in marine environments are largely unexplored. In the present study mac genes were examined in marine environments by analyzing 101 biofilm and 91 seawater metagenomes. There were more mac genes in biofilms than in seawater, and substratum type, location, or sampling time did not affect the mac genes in biofilms. The mac gene clusters were highly diverse and often incomplete while the three MAC components co-occurred with other genes of different functions. Genomic analysis of four Pseudoalteromonas and two Streptomyces strains revealed the mac genes transfers among different microbial taxa. It is proposed that mac genes are more specific to biofilms; gene transfer among different microbial taxa has led to highly diverse mac gene clusters; and in most cases, the three MAC components function individually rather than forming a complex.

Morphology and genome of a snailfish from the Mariana Trench provide insights into deep-sea adaptation.

It is largely unknown how living organisms-especially vertebrates-survive and thrive in the coldness, darkness and high pressures of the hadal zone. Here, we describe the unique morphology and genome of Pseudoliparis swirei-a recently described snailfish species living below a depth of 6,000 m in the Mariana Trench. Unlike closely related shallow sea species, P. swirei has transparent, unpigmented skin and scales, thin and incompletely ossified bones, an inflated stomach and a non-closed skull. Phylogenetic analyses show that P. swirei diverged from a close relative living near the sea surface about 20 million years ago and has abundant genetic diversity. Genomic analyses reveal that: (1) the bone Gla protein (bglap) gene has a frameshift mutation that may cause early termination of cartilage calcification; (2) cell membrane fluidity and transport protein activity in P. swirei may have been enhanced by changes in protein sequences and gene expansion; and (3) the stability of its proteins may have been increased by critical mutations in the trimethylamine N-oxide-synthesizing enzyme and hsp90 chaperone protein. Our results provide insights into the morphological, physiological and molecular evolution of hadal vertebrates.

Periodic and Spatial Spreading of Alkanes and Alcanivorax Bacteria in Deep Waters of the Mariana Trench.

In subduction zones, serpentinization and biological processes may release alkanes to the deep waters, which would probably result in the rapid spread of Alcanivorax However, the timing and area of the alkane distribution and associated enrichment of alkane-degrading microbes in the dark world of the deep ocean have not been explored. In this study, we report the richness (up to 17.8%) of alkane-degrading bacteria, represented by Alcanivorax jadensis, in deep water samples obtained at 3,000 to 6,000 m in the Mariana Trench in two cruises. The relative abundance of A. jadensis correlated with copy numbers of functional almA and alkB genes, which are involved in alkane degradation. In these water samples, we detected a high flux of alkanes, which probably resulted in the prevalence of A. jadensis in the deep waters. Contigs of A. jadensis were binned from the metagenomes for examination of alkane degradation pathways and deep sea-specific pathways, which revealed a lack of nitrate and nitrite dissimilatory reduction in our A. jadensis strains. Comparing the results for the two cruises conducted close to each other, we suggest periodic release of alkanes that may spread widely but periodically in the trench. Distribution of alkane-degrading bacteria in the world's oceans suggests the periodic and remarkable contributions of Alcanivorax to the deep sea organic carbon and nitrogen sources.IMPORTANCE In the oligotrophic environment of the Mariana Trench, alkanes as carbohydrates are important for the ecosystem, but their spatial and periodic spreading in deep waters has never been reported. Alkane-degrading bacteria such as Alcanivorax spp. are biological signals of the alkane distribution. In the present study, Alcanivorax was abundant in some waters, at depths of up to 6,000 m, in the Mariana Trench. Genomic, transcriptomic, and chemical analyses provide evidence for the presence and activities of Alcanivorax jadensis in deep sea zones. The periodic spreading of alkanes, probably from the subductive plates, might have fundamentally modified the local microbial communities, as well as perhaps the deep sea microenvironment.

Genomics insights into ecotype formation of ammonia-oxidizing archaea in the deep ocean.

Various lineages of ammonia-oxidizing archaea (AOA) are present in deep waters, but the mechanisms that determine ecotype formation are obscure. We studied 18 high-quality genomes of the marine group I AOA lineages (alpha, gamma and delta) from the Mariana and Ogasawara trenches. The genomes of alpha AOA resembled each other, while those of gamma and delta lineages were more divergent and had even undergone insertion of some phage genes. The instability of the gamma and delta AOA genomes could be partially due to the loss of DNA polymerase B (polB) and methyladenine DNA glycosylase (tag) genes responsible for the repair of point mutations. The alpha AOA genomes harbour genes encoding a thrombospondin-like outer membrane structure that probably serves as a barrier to gene flow. Moreover, the gamma and alpha AOA lineages rely on vitamin B12 -independent MetE and B12 -dependent MetH, respectively, for methionine synthesis. The delta AOA genome contains genes involved in uptake of sugar and peptide perhaps for heterotrophic lifestyle. Our study provides insights into co-occurrence of cladogenesis and anagenesis in the formation of AOA ecotypes that perform differently in nitrogen and carbon cycling in dark oceans.

The Cyanobacteria-Dominated Sponge Dactylospongia elegans in the South China Sea: Prokaryotic Community and Metagenomic Insights.

The South China Sea is a special reservoir of sponges of which prokaryotic communities are less studied. Here, a new record of the sponge Dactylospongia elegans is reported near the coast of Jinqing Island in the South China Sea, and its prokaryotic community is comprehensively investigated. Sponge specimens displayed lower microbial diversity compared with surrounding seawater. At the phylum level, prokaryotic communities were consistently dominated by Proteobacteria, followed by Cyanobacteria, Chloroflexi, Acidobacteria, Actinobacteria, Gemmatimonadetes, Thaumarchaeota, and Poribacteria. Operational taxonomic unit (OTU) analysis alternatively showed that the most abundant symbiont was the sponge-specific cyanobacterial species "Candidatus Synechococcus spongiarum," followed by OTUs belonging to the unidentified Chloroflexi and Acidobacteria. Phylogenetic tree based on 16S-23S internal transcribed spacer regions indicated that the dominated cyanobacterial OTU represented a new clade of "Ca. Synechococcus spongiarum." More reliable metagenomic data further revealed that poribacterial symbionts were highly abundant and only secondary to the cyanobacterial symbiont. One draft genome for each of the Cyanobacteria, Chloroflexi and Acidobacteria and three poribacterial genomes were extracted from the metagenomes. Among them, genomes affiliated with the Chloroflexi and Acidobacteria were reported for the first time in sponge symbionts. Eukaryotic-like domains were found in all the binned genomes, indicating their potential symbiotic roles with the sponge host. The high quality of the six recovered genomes of sponge symbionts from the sponge D. elegans makes it possible to understand their symbiotic roles and interactions with the sponge host as well as among one another.

Genomic characterization of symbiotic mycoplasmas from the stomach of deep-sea isopod bathynomus sp.

Deep-sea isopod scavengers such as Bathynomus sp. are able to live in nutrient-poor environments, which is likely attributable to the presence of symbiotic microbes in their stomach. In this study we recovered two draft genomes of mycoplasmas, Bg1 and Bg2, from the metagenomes of the stomach contents and stomach sac of a Bathynomus sp. sample from the South China Sea (depth of 898 m). Phylogenetic trees revealed a considerable genetic distance to other mycoplasma species for Bg1 and Bg2. Compared with terrestrial symbiotic mycoplasmas, the Bg1 and Bg2 genomes were enriched with genes encoding phosphoenolpyruvate-dependent phosphotransferase systems (PTSs) and sodium-driven symporters responsible for the uptake of sugars, amino acids and other carbohydrates. The genome of mycoplasma Bg1 contained sialic acid lyase and transporter genes, potentially enabling the bacteria to attach to the stomach sac and obtain organic carbons from various cell walls. Both of the mycoplasma genomes contained multiple copies of genes related to proteolysis and oligosaccharide degradation, which may help the host survive in low-nutrient conditions. The discovery of the different types of mycoplasma bacteria in the stomach of this deep-sea isopod affords insights into symbiotic model of deep-sea animals and genomic plasticity of mycoplasma bacteria.

Pyrosequencing revealed shifts of prokaryotic communities between healthy and disease-like tissues of the Red Sea sponge Crella cyathophora.

Sponge diseases have been widely reported, yet the causal factors and major pathogenic microbes remain elusive. In this study, two individuals of the sponge Crella cyathophora in total that showed similar disease-like characteristics were collected from two different locations along the Red Sea coast separated by more than 30 kilometers. The disease-like parts of the two individuals were both covered by green surfaces, and the body size was much smaller compared with adjacent healthy regions. Here, using high-throughput pyrosequencing technology, we investigated the prokaryotic communities in healthy and disease-like sponge tissues as well as adjacent seawater. Microbes in healthy tissues belonged mainly to the Proteobacteria, Cyanobacteria and Bacteroidetes, and were much more diverse at the phylum level than reported previously. Interestingly, the disease-like tissues from the two sponge individuals underwent shifts of prokaryotic communities and were both enriched with a novel clade affiliated with the phylum Verrucomicrobia, implying its intimate connection with the disease-like Red Sea sponge C. cyathophora. Enrichment of the phylum Verrucomicrobia was also considered to be correlated with the presence of algae assemblages forming the green surface of the disease-like sponge tissues. This finding represents an interesting case of sponge disease and is valuable for further study.