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. 2018 Dec 11;5:180285. doi: 10.1038/sdata.2018.285

Comparative shotgun metagenomic data of the silkworm Bombyx mori gut microbiome

Bosheng Chen 1, Ting Yu 1, Sen Xie 1, Kaiqian Du 1, Xili Liang 1, Yahua Lan 1, Chao Sun 2, Xingmeng Lu 1, Yongqi Shao 1,3,a
PMCID: PMC6289112  PMID: 30532085

Abstract

Lepidoptera (butterflies and moths) is a major insect order including important pollinators and agricultural pests, however their microbiomes are little studied. Here, using next-generation sequencing (NGS)-based shotgun metagenomics, we characterize both the biodiversity and functional potential of gut microbiota of a lepidopteran model insect, the silkworm Bombyx mori. Two metagenomes, including the standard inbred strain Dazao (P50) and an improved hybrid strain Qiufeng × Baiyu (QB) widely used in commercial silk production, were generated, containing 45,505,084 and 69,127,002 raw reads, respectively. Taxonomic analysis revealed that a total of 663 bacterial species were identified in P50 silkworms, while 322 unique species in QB silkworms. Notably, Enterobacter, Acinetobacter and Enterococcus were dominated in both strains. The further functional annotation was performed by both BlastP and MG-RAST against various databases including Nr, COG, KEGG, CAZy and SignalP, which revealed >5 × 106 protein-coding genes. These datasets not only provide first insights into all bacterial genes in silkworm guts, but also help to generate hypotheses for subsequently testing functional traits of gut microbiota in an important insect group.

Subject terms: Metagenomics, Entomology

Background & Summary

Insects are the most diverse and largest class of animals on Earth, occupying in nearly all terrestrial ecological niches. Owing to this great diversity and the long-time coexistence, an amazing variety of symbiotic microorganisms have adapted specifically to insects as hosts, and participate in many relationships with the hosts1–4. In particular, the gut of most insects harbors a rich and complex microbial community with considerable metabolic activity5,6, which range from enhancing host energy metabolism to shaping immune system7–11. For example, various polysaccharide degrading bacteria were identified from herbivorous insect gut, which produce enzymes degrading otherwise host-indigestible plant component (e.g. cellulose, xylan)12–16. The native gut microbiota is also more and more recognized to play as an “extended immune system” for the host against harmful microbes17. Abundant lactic acid bacteria maintain in biofilms within honeybees (Apis mellifera) and work in a synergistic matter to inhibit pathogen proliferation in the gut by producing a mixture of antimicrobials18.

Although Lepidoptera, including butterflies and moths, is one of the largest insect orders and a primary group of phytophagous agricultural pests, little is known about the microbes associated with them19,20. Indeed, by using high-throughput sequencing techniques, recently several studies have reported abundant and diverse bacteria in lepidopteran guts8,21–24, but the functional significance of their gut microbiomes still remains undetermined. As a lepidopteran model organism and domesticated insect25, the silkworm Bombyx mori (Lepidoptera: Bombycidae) is important not only for basic research but also for providing raw materials to the textile and biotechnology industry16,26–28. Based on this model insect, the metagenomic analysis could form the basis for further research of lepidopteran microbiome.

Here, using next-generation sequencing, we present shotgun gut metagenomes from two most common silkworm strains, namely Dazao (P50) and Qiufeng × Baiyu (QB). The inbred P50 silkworms are extensively used worldwide, as the standard strain for B. mori research; while the hybrid QB silkworms are widely used in local commercial silk production, which have a higher growth rate (Fig. 1a) and a larger cocoon size than P50 (Fig. 1b). Sample information was detailed in Table 1. As a herbivorous insect, the gut of silkworm is full filled with plant tissues, making it necessary to separate bacterial cells from the gut content to avoid plant DNA contamination. Thus, a filtration and density gradient centrifuge procedure was applied to enrich gut bacteria from the silkworm13. After bacterial DNA extraction, the metagenome was sequenced and analysed as the flowchart shown in Fig. 1c.

Figure 1. Silkworm (Bombyx mori) strains used for this study and overview of the experimental design.

Figure 1

(a) The hybrid QB silkworm has a higher growth rate than P50. (b) Cocoon size and shape of P50 (yellow) and QB (white). (c) Workflow used to process silkworm gut samples to generate metagenomes. (d) Length distributions of filtered metagenome sequencing reads. (e) The functional gene rarefaction curve for each strain. (f) The taxonomical diversity rarefaction curve for each strain.

Table 1. Sample information in this study.

Sample Biome Feature Material Geographical location GeoPosition Protocol
MS1P50 Insect gut Digestive tract environment Gut tissue Hangzhou of Zhejiang province, China 120.098057, 30.305965, 5 m Shotgun Metagenome
MS1QB Insect gut Digestive tract environment Gut tissue Hangzhou of Zhejiang province, China 120.098057, 30.305965, 5 m Shotgun Metagenome
16SSP50 Insect gut Digestive tract environment Gut tissue Hangzhou of Zhejiang province, China 120.098057, 30.305965, 5 m 16S rRNA amplicon
16SSQB Insect gut Digestive tract environment Gut tissue Hangzhou of Zhejiang province, China 120.098057, 30.305965, 5 m 16S rRNA amplicon

Shotgun sequencing produced 6.826 and 10.369 Giga base pairs (Gbp) of unassembled sequence data from P50 (MS1P50) and QB (MS1QB) samples (Table 2). In total, 44,047,886 and 67,718,490 sequences passed the quality control in the MS1P50 and MS1QB dataset, respectively. Read length distribution after filtering revealed most of sequences between 201–600 bp (Fig. 1d), and rarefaction curves tended towards saturation (Fig. 1e,f). The metagenomes were assembled separately into 91,037 and 44,201 scaffolds with 53.91 and 54.49% GC content in P50 and QB, respectively (Table 2). After ORF prediction, 148,685 ORFs from MS1P50 and 75,232 ORFs from MS1QB were identified. Table 3 summarizes functional gene annotation against various databases. By using both BlastP and MG-RAST protocols, the metabolism was found to be the major part of silkworm gut microbiome function (Fig. 2). From the Nr database output, 2,307,446 and 5,036,416 reads of P50 and QB were aligned to this category respectively, indicating that nutrient digestion and synthesis were most important aspects and microbial fermented products such as lactic acid, butyrate and vitamins29–31, could also be supplied to the host. Table 4 reveals that most reads ( >99%) identified from silkworm gut metagenome belong to the domain Bacteria. Taxonomic diversity was analysed not only with shotgun metagenomic data by different tools (BlastP against Nr database and MG-RAST against GenBank), but also by direct 16 S rRNA sequencing32, which showed the same tendency (Table 5). Enterococcus, Acinetobacter, Bacillus and Enterobacter are dominant species in both strains (Fig. 3) and have previously been found in silkworms33.

Table 2. Metagenome sequencing statistics reported in this study.

Sample MS1P50 MS1QB
Sequence size (Gbp) 6.826 10.369
No. of reads 45,505,084 69,127,002
Sequence strategy Paired-end Paired-end
Library insert size 500 500
Average read length 150 150
No. of sequences removed by quality control procedures 1,457,198 1,408,512
No. of sequences that passed quality control procedures 44,047,886 67,718,490
Number of scaffolds ( >500 bps) after assembled 91,037 44,201
Total Bases in scaffolds > 500 bps 93,065,111 49,571,885
% of Sequences assembled 93.50% 98%
No. of singletons after assembly 0 0
N rate 0% 0%
Largest scaffold length (bp) 18,177 52,980
N50 scaffold length (bp) 1,076 1,214
N90 scaffold length (bp) 564 578
GC content 53.91% 54.49%
ORFs ( >100 bps) 148,685 75,232
Average ORF length (bp) 546.7 576.3

Table 3. Annotation summary.

Databases Numbers of reads annotated
MS1P50 MS1QB
Nr 6,474,494 14,568,868
COG 5,842,302 13,008,590
KEGG 3,333,526 7,823,300
CAZy 175,548 546,668
ARDB 10,040 27,756
SignalP 437,774 945,626

Figure 2. Composition of metabolism category in COG.

Figure 2

BlastP (denoted with circle symbols) and MG-RAST (denoted with triangle symbols) methods are used respectively to query against COG database. Best hits of two strains are shown in the bar plot in the upper right panel.

Table 4. Domain coverage of shotgun reads.

Domain Shotgun reads
MS1P50 (%) MS1QB (%)
Archaea 22 (0.00%) 440 (0.01%)
Bacteria 11,706,480 (99.94%) 4,055,040 (99.23%)
Eukaryota 5,858 (0.05%) 27,190 (0.67%)
Viruses 810 (0.01%) 3,784 (0.09%)
No rank 18 (0.00%) 2 (0.00%)

Table 5. Taxonomic composition (top 15) revealed by 16S rRNA sequencing and shotgun metagenomic sequencing.

Genus 16S rRNA sequencing (RDP database)
Shotgun metagenome sequencing (Nr database)
16SSP50 (%) 16SSQB (%) MS1P50(%) MS1QB (%)
Enterococcus 1,675 (5.0%) 14,576 (43.8%) 765,432 (18.7%) 7,412,022 (63.3%)
Acinetobacter 7,117 (21.3%) 4,895 (14.7%) 663,036 (16.2%) 340,064 (2.9%)
Enterobacter 5,295 (15.8%) 6,021 (18.1%) 198,836 (4.9%) 1,265,284 (10.8%)
Aeromonas 5,954 (17.8%) 0 (0%) 354,508 (8.7%) 150 (0.0013%)
Stenotrophomonas 1,491 (4.4%) 3,773 (11.3%) 69,468 (1.7%) 785,760 (6.7%)
Bacillus 2,910 (8.7%) 728 (2.2%) 225,798 (5.5%) 54,856 (0.47%)
Staphylococcus 2,473 (7.4%) 224 (0.67%) 56,150 (1.4%) 58,798 (0.50%)
Planococcaceae_unclassified 2,064 (6.2%) 111 (0.33%)
Arthrobacter 734 (2.2%) 793 (2.4%) 57,282 (1.4%) 11,268 (0.096%)
Comamonas 1,004 (3.0%) 0 (0%) 27,974 (0.68%) 8,644 (0.074%)
Delftia 242 (0.70%) 534 (1.6%) 100,894 (2.5%) 139,532 (1.2%)
Methylobacterium 751 (2.2%) 9 (0.027%) 12,394 (0.30%) 254 (0.0022%)
Enterobacteriaceae_unclassified 20 (0.05%) 606 (1.8%)
Pseudomonas 138 (0.41%) 269 (0.81%) 25,140 (0.62%) 122,492 (1.0%)
Aureimonas 389 (1.2%) 3 (0.0090%) 2,590 (0.063%) 6 (0.00%)
Total reads 33,473 33,254 4,086,456 11,713,188

Figure 3. Species abundance and phylogenetic relationship of gut bacteria between P50 and QB.

Figure 3

The phylogenetic tree is shown at the genus level, colored by the phylum. Bacterial abundance is indicated in outer ring with shape plot (P50, blue circle; QB, red circle). The size of circle represents sequence log10 reads per genus.

Altogether, the community structure and functional genes described here could be used for further exploring the potential relationship between the Lepidoptera host and commensal bacteria, thereby paving the way for developing novel strategies to promote silk production and enhancing studies on insect symbiosis.

Methods

Insect rearing and sample collection

Eggs of P50 and QB were provided by the Silkworm Quality Inspection and Quarantine Station, Department of Agriculture, Zhejiang Province, China. Silkworms were hatched in an incubator at 28 °C, 100% RH, and maintained in sealed plastic boxes (50 × 25 × 10 cm) with light-dark regime (16:8) at 25 °C and 70% RH. The 5th-instar larvae feeding with fresh mulberry leaves were used in this study. After 5 days feeding ad libitum, a hundred of P50 and QB silkworms were collected.

Gut dissection was performed as described previously34. Freeze-killed silkworms were washed with ddH2O for three times after surface-sterilization in 70% ethanol for 30 s. The larvae were dissected on ice in a clean bench. Considering that a large amount of bacterial DNA is needed for shotgun metagenomic sequencing and a risk for sample loss during purifying bacteria, dissected guts were pooled for DNA extraction and subsequent sequencing. Briefly, for each silkworm strain, 100 guts were homogenized with a hand-held homogenizer (PRO scientific, Monroe, USA). In order to avoid the plant and host tissue debris contamination, several steps of filtering were applied followed by a protocol specific for gut bacteria enrichment35. 100 mL 10 mM MgSO4 was then added to homogenized samples before being passed through 20 μm and 11 μm filters (Millipore, Bedford, USA). Each sample was centrifuged at 4000 rpm for 15 min. The pellet was resuspended with 200 μL ddH2O for further separation. 40 and 80% Percoll (GE Healthcare, Uppsala, Sweden) containing 10 mM MgSO4, 0.01% bovine serum albumen, 0.01% ficoll (Sangon, Shanghai, China), 0.05% polyethyleneglycol 6000 (Sangon, Shanghai, China), and 0.086% sucrose were used for the density gradient centrifugation. Each 7-mL centrifuge tube (Hitachi, Tokyo, Japan) was filled with 2.5 mL 80% Percoll on bottom layer, and 3.5 mL 40% Percoll on the top layer. Next, 1 mL of the sample was placed gently on the top of 40% gradient layer. The prepared tubes were centrifuged at 12,000 rpm, 4 °C for 10 min and bacterial cells were collected at the interface between the 40 and 80% Percoll solutions. Collected cells were washed by 1 mL of 10 mM MgSO4 for three times (4000 rpm, 5 min). The pelleted bacteria were used for DNA extraction.

DNA extraction and shotgun metagenomic sequencing

To remove the host genetic contamination in samples, DNase I (Epicentre, Madison, USA) was added in and incubated at 37 °C for 30 min. After DNA digestion, 1 volume of 0.5 M EDTA (Sangon, Shanghai, China) was added and heated at 72 °C for 2 min to inactivate the DNase enzyme. Bacterial DNA was extracted from the washed cells by using the MasterPure™ Complete DNA and RNA Purification Kit (Epicentre, Madison, USA). The extracted DNA was quantified for the Illumina high-throughput sequencing (Illumina, San Diego, CA). 3 μg genomic DNA per sample was used for the sequencing library preparation. DNA samples were first fragmented into 300 bp fragments by the Covaris M220 shearing system (Covaris, Woburn, USA). Illumina TruSeq™ DNA Sample Prep Kit (Illumina, San Diego, CA) was then employed for the generation of 150 bp pair-end (PE) libraries following manufacturer’s recommendations. Illumina cBot Truseq PE Cluster Kit v3-cBot-HS (Illumina, San Diego, CA) was used for PCR reaction to enrich DNA fragments with ligated adapters on both ends. NGS sequencing was performed by Illumina Hiseq 2500 sequencing platform (Illumina, San Diego, CA), resulting two fastq files for each run.

Metagenome sequence processing

Sequences with an average read length of 150 bp were introduced into SeqPrep (https://github.com/jstjohn/SeqPrep) to remove the adapter at 3′ ends of raw reads. Raw sequences containing 3 or more unknown nucleotides (‘N’) were trimmed by Sickle (https://github.com/najoshi/sickle) command “sickle pe” to obtain clean reads longer than 20 bp, and to ensure that filtered reads possessed quality threshold greater than 20. Clean reads were then assembled by SOAPdenovo36 at 39–47 k-mers. Scaffolds < 500 bp were excluded. To construct a non-redundant gene set, CD-HIT37 was employed to cluster assembled reads at 90% coverage and 95% identity, using the longest read as the representative sequence. All high quality reads were aligned (95% identity) against non-redundant database using SOAPaligner (http://soap.genomics.org.cn/) to obtain the gene abundance in each sample.

Metagenome annotation

After extraction of the non-redundant gene set, annotation was performed against Nr database by BlastP (v2.2.28+ ) at an e-value cutoff of 10−10, and the dataset was also processed by the web-based metagenomics RAST server (MG-RAST)38–40. Various databases (Table 3) were used for annotation41. KEGG42 and COG43 were employed too for the alignment of functional genes. To get the information about carbohydrate active enzymes and antibiotic resistant genes, sequences were compared in the CAZy44 and ARDB45 databases, respectively. Proteins transported through the secretory pathway, which contain signal peptides, were identified by SignalP programme46. The ratio of annotated genes were determined by read number of the hits to the non-redundant database. From the annotation results, contamination sequences of the host silkworm were removed. Rarefaction curve was generated by R package vegan, based on the output file of Nr annotation.

16S rRNA sequencing and taxonomic analysis

For amplicon sequencing library preparation, a 50 μL PCR reaction system containing 10 μL 5 × FastPfu reaction buffer, 2.5 U FastPfu Polymerase (Transgene, Beijing, China), 250 μM dNTPs, 200 nM of primers, 1 μL of DNA sample and DNA-free water was performed twice to link the sequencing adapter to the PCR products. The resulting fragments were pooled together equally and quantified by Quantifluor dsDNA system (Promega, Madison, USA). PE sequencing was performed on an Illumina MiSeq instrument (Illumina, San Diego, CA).

Raw PE reads were merged by FLASH software (v1.2.7), and trimmed with Trimmomatic (v0.36) (Q > 20, N bases < 1%). Clean reads were run through UCHIME (v7.1) to remove all chimeric sequences. UCLUST implemented in QIIME (v1.8.0)47 was used for OTU clustering at threshold 97%, then the representative sequences were selected by the pick_rep_set.py script in QIIME. Taxonomic classification was performed using RDP Classifier (v2.12) with a confidence cutoff of 0.8. Phylogenetic tree was used to exhibit the gut microbiota composition of silkworm48. The longest read of each bacteria genus was picked out to generate the tree (Maxium-likelihood tree, Tamura-Nei model and bootstrap 1000)49, and visualized using iTOL50. Unclassified OTUs were further identified with BLASTN51.

Code availability

No custom code was used to generate or process these data. Software versions employed are as follows:

BlastP (v2.2.28 + )

FLASH (v1.2.7)

Trimmomatic (v0.36)

UCHIME (v7.1)

QIIME (v1.8.0)

RDP Classifier (v2.12)

iTOL (v3)

Data Records

Raw data of shotgun metagenomic sequencing (fastq file) are available from the NCBI’s Sequence Read Archive (Data Citation 1 and Data Citation 2). Raw data of 16 S rRNA sequencing (fastq file) are available from the NCBI’s Sequence Read Archive (Data Citation 3 and Data Citation 4). All shotgun metagenomic sequencing data can be also found at the MG-RAST server (for the strain P50: http://www.mg-rast.org/mgmain.html?mgpage=overview&metagenome=mgm4767611.3; strain QB: http://www.mg-rast.org/mgmain.html?mgpage=overview&metagenome=mgm4754041.3). The annotation outputs generated in this work include the non-redundant gene set.fa file (Data Citation 5) and the Annotation_results.xlsx file produced through BlastP, MG-RAST, SignalP, and comparisons to the CAZy and ARDB databases (Data Citation 5). The outputs of taxonomic analyses include: (i) an OTU table BIOM file with taxonomic assignment generated from 16 S rRNA sequencing (Data Citation 5) (ii) bacterial abundance at the genus level (Data Citation 5) (iii) aligned sequences for generating the phylogenetic tree (Fig. 3) in Newick format (Data Citation 5), and (iv) taxonomic assignment based on all bacterial gene sequences identified in the shotgun assemblies (Data Citation 5).

Technical Validation

Like other herbivorous caterpillars, the silkworm infests a large amount of plant tissues and its gut full filled with mulberry leaf materials. Therefore, direct DNA extraction from gut content for metagenome analysis commonly fails to capture sufficient bacterial sequences, being masked by overwhelmingly abundant plant DNA sequences, such as the chloroplast contamination. To overcome this limitation, we first filtered the homogenized gut tissue to remove most of plant particles from our sample. Then a Percoll-based density gradient centrifugation was performed to enrich gut bacteria accordingly13. Moreover, before DNA extraction, DNase was applied to remove host DNA contamination from bacterial cell suspension, finally this enzyme was inactivated by heating at 72 °C for 2 min.

For assessing shotgun metagenome data, we compared two universal protocols with the dataset, namely BlastP and MG-RAST38,39, both providing integrative analyses of sequences. Overall, the MG-RAST analysis agreed with BlastP analysis for both taxonomy and functional results (Fig. 2), indicating that there was no obvious technical bias for analyzing shotgun metagenomes in this study. Furthermore, for the 16 S rRNA gene classification, BLASTN was employed to identify the reads labelled “unclassified” at the genus level. The comparison of bacterial taxonomy data between 16 S rRNA sequencing (based on the RDP database) and shotgun metagenomic sequencing (based on Nr database) results verified the community structure.

Additional information

How to cite this article: Chen, B. et al. Comparative shotgun metagenomic data of the silkworm Bombyx mori gut microbiome. Sci. Data. 5:180285 doi: 10.1038/sdata.2018.285 (2018).

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Material

sdata2018285-isa1.zip (2.9KB, zip)

Acknowledgments

This work was supported by grants from National Key R&D Program of China (No. 2017YFD0400302), Zhejiang province analysis and testing science and technology project (No. 2018C37060 to C. Sun), the Fundamental Research Funds for the Central Universities (No. 2017QNA6024), China Agriculture Research System (No. CARS-18-ZJ0302) and the National Natural Science Foundation of China (No. 31601906).

Footnotes

The authors declare no competing interests.

Data Citations

  1. 2017. NCBI Sequence Read Archive. SRX3209014
  2. 2017. NCBI Sequence Read Archive. SRX3207342
  3. 2018. NCBI Sequence Read Archive. SRX4519345
  4. 2018. NCBI Sequence Read Archive. SRX4515224
  5. Chen B., et al. . 2018. figshare. https://doi.org/10.6084/m9.figshare.c.4249433.v1

References

  1. Berasategui A., Shukla S., Salem H. & Kaltenpoth M. Potential applications of insect symbionts in biotechnology. Appl. Microbiol. Biotechnol. 100, 1567–1577 (2016). [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Douglas A. E. Lessons from studying insect symbioses. Cell Host Microbe 10, 359–367 (2011). [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Moya A., Peretó J., Gil R. & Latorre A. Learning how to live together: Genomic insights into prokaryote-animal symbioses. Nat. Rev. Genet. 9, 218–229 (2008). [DOI] [PubMed] [Google Scholar]
  4. Douglas A. E. Multiorganismal insects: Diversity and function of resident microorganisms. Annu. Rev. Entomol. 60, 17–34 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dillon R. J. & Dillon V. M. The gut bacteria of insects: Nonpathogenic interactions. Annu. Rev. Entomol. 49, 71–92 (2004). [DOI] [PubMed] [Google Scholar]
  6. Engel P. & Moran N. A. The gut microbiota of insects - diversity in structure and function. FEMS Microbiol. Rev. 37, 699–735 (2013). [DOI] [PubMed] [Google Scholar]
  7. Shao Y. et al. Symbiont-derived antimicrobials contribute to the control of the lepidopteran gut microbiota. Cell Chem. Biol. 24, 66–75 (2017). [DOI] [PubMed] [Google Scholar]
  8. Chen B. et al. Biodiversity and activity of the gut microbiota across the life history of the insect herbivore spodoptera littoralis. Sci. Rep 6, 29505 (2016). [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Sudakaran S., Retz F., Kikuchi Y., Kost C. & Kaltenpoth M. Evolutionary transition in symbiotic syndromes enabled diversification of phytophagous insects on an imbalanced diet. ISME J. 12, 2587–2604 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Salem H. et al. Vitamin supplementation by gut symbionts ensures metabolic homeostasis in an insect host. Proc. Biol. Sci 281, 20141838 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Fischer C. N. et al. Metabolite exchange between microbiome members produces compounds that influence drosophila behavior. eLife 6, e18855 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Flint H. J., Scott K. P., Duncan S. H., Louis P. & Forano E. Microbial degradation of complex carbohydrates in the gut. Gut Microbes 3, 289–306 (2012). [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Engel P., Martinson V. G. & Moran N. A. Functional diversity within the simple gut microbiota of the honey bee. Proc. Natl Acad. Sci. USA 109, 11002–11007 (2012). [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Dantur K. I., Enrique R., Welin B. & Castagnaro A. P. Isolation of cellulolytic bacteria from the intestine of diatraea saccharalis larvae and evaluation of their capacity to degrade sugarcane biomass. AMB Express 5, 15 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Moraes C. D. et al. Expression pattern of glycoside hydrolase genes in lutzomyia longipalpis reveals key enzymes involved in larval digestion. Front. Physiol 5, 276 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Liang X. et al. Insect symbionts as valuable grist for the biotechnological mill: An alkaliphilic silkworm gut bacterium for efficient lactic acid production. Appl. Microbiol. Biotechnol. 102, 4951–4962 (2018). [DOI] [PubMed] [Google Scholar]
  17. Koch H. & Schmid-Hempel P. Socially transmitted gut microbiota protect bumble bees against an intestinal parasite. Proc. Natl Acad. Sci. USA 108, 19288–19292 (2011). [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Vasquez A. et al. Symbionts as major modulators of insect health: Lactic acid bacteria and honeybees. PLoS ONE 7, e33188 (2012). [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Paniagua Voirol L. R., Frago E., Kaltenpoth M., Hilker M. & Fatouros N. E. Bacterial symbionts in lepidoptera: Their diversity, transmission, and impact on the host. Front. Microbiol 9, 556 (2018). [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Mereghetti V., Chouaia B. & Montagna M. New insights into the microbiota of moth pests. Int. J. Mol. Sci. 18, 2450 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Chen B. et al. Gut bacterial and fungal communities of the domesticated silkworm (bombyx mori) and wild mulberry-feeding relatives. ISME J. 12, 2252–2262 (2018). [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Xia X. et al. Gut microbiota mediate insecticide resistance in the diamondback moth, plutella xylostella (L.). Front. Microbiol 9, 25 (2018). [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Mereghetti V., Chouaia B., Limonta L., Locatelli D. P. & Montagna M. Evidence for a conserved microbiota across the different developmental stages of plodia interpunctella. Insect Sci. 00, 1–13 (2017). [DOI] [PubMed] [Google Scholar]
  24. Ruokolainen L., Ikonen S., Makkonen H. & Hanski I. Larval growth rate is associated with the composition of the gut microbiota in the glanville fritillary butterfly. Oecologia 181, 895–903 (2016). [DOI] [PubMed] [Google Scholar]
  25. International Silkworm Genome, C. The genome of a lepidopteran model insect, the silkworm bombyx mori. Insect. Biochem. Mol. Biol. 38, 1036–1045 (2008). [DOI] [PubMed] [Google Scholar]
  26. Goldsmith M. R., Shimada T. & Abe H. The genetics and genomics of the silkworm, bombyx mori. Annu. Rev. Entomol. 50, 71–100 (2005). [DOI] [PubMed] [Google Scholar]
  27. Kaito C., Akimitsu N., Watanabe H. & Sekimizu K. Silkworm larvae as an animal model of bacterial infection pathogenic to humans. Microb. Pathog. 32, 183–190 (2002). [DOI] [PubMed] [Google Scholar]
  28. Xu H. & O’Brochta D. A. Advanced technologies for genetically manipulating the silkworm bombyx mori, a model lepidopteran insect. Proc. Biol. Sci 282, 20150487 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Wee Y. J., Yun J. S., Park D. H. & Ryu H. W. Biotechnological production of l( + )-lactic acid from wood hydrolyzate by batch fermentation of enterococcus faecalis. Biotechnol. Lett. 26, 71–74 (2004). [DOI] [PubMed] [Google Scholar]
  30. Vital M., Howe A. C. & Tiedje J. M. Revealing the bacterial butyrate synthesis pathways by analyzing (meta)genomic data. MBio 5, e00889 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. LeBlanc J. G. et al. Bacteria as vitamin suppliers to their host: A gut microbiota perspective. Curr. Opin. Biotechnol. 24, 160–168 (2013). [DOI] [PubMed] [Google Scholar]
  32. Siegwald L. et al. Targeted metagenomic sequencing data of human gut microbiota associated with blastocystis colonization. Sci. Data 4, 170081 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Liang X., Fu Y., Tong L. & Liu H. Microbial shifts of the silkworm larval gut in response to lettuce leaf feeding. Appl. Microbiol. Biotechnol. 98, 3769–3776 (2014). [DOI] [PubMed] [Google Scholar]
  34. Shao Y., Arias-Cordero E. M. & Boland W. Identification of metabolically active bacteria in the gut of the generalist spodoptera littoralis via DNA stable isotope probing using 13c-glucose. J. Vis. Exp 81, e50734 (2013). [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Teh B. S., Apel J., Shao Y. Q. & Boland W. Colonization of the intestinal tract of the polyphagous pest spodoptera littoralis with the gfp-tagged indigenous gut bacterium enterococcus mundtii. Front. Microbiol 7, 928 (2016). [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Li R. et al. De novo assembly of human genomes with massively parallel short read sequencing. Genome Res. 20, 265–272 (2010). [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Li W. & Godzik A. Cd-hit: A fast program for clustering and comparing large sets of protein or nucleotide sequences. Bioinformatics 22, 1658–1659 (2006). [DOI] [PubMed] [Google Scholar]
  38. Glass E. M., Wilkening J., Wilke A., Antonopoulos D. & Meyer F. Using the metagenomics rast server (mg-rast) for analyzing shotgun metagenomes. Cold Spring Harb. Protoc 2010, 5368 (2010). [DOI] [PubMed] [Google Scholar]
  39. Meyer F. et al. The metagenomics rast server – a public resource for the automatic phylogenetic and functional analysis of metagenomes. BMC Bioinformatics 9, 386–386 (2008). [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Benson D. A., Karsch-Mizrachi I., Lipman D. J., Ostell J. & Wheeler D. L. Genbank. Nucleic Acids Res 34, 16–20 (2006). [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Gong L. et al. Complete genome sequencing of the luminescent bacterium, vibrio qinghaiensis sp q67 using pacbio technology. Sci. Data 5, 170205 (2018). [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Kanehisa M. & Goto S. Kegg: Kyoto encyclopedia of genes and genomes. Nucleic Acids Res 28, 27–30 (2000). [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Tatusov R. L., Koonin E. V. & Lipman D. J. A genomic perspective on protein families. Science 278, 631–637 (1997). [DOI] [PubMed] [Google Scholar]
  44. Lombard V., Golaconda Ramulu H., Drula E., Coutinho P. M. & Henrissat B. The carbohydrate-active enzymes database (cazy) in 2013. Nucleic Acids Res 42, 490–495 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Liu B. & Pop M. Ardb--antibiotic resistance genes database. Nucleic Acids Res 37, 443–447 (2009). [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Petersen T. N., Brunak S., von Heijne G. & Nielsen H. Signalp 4.0: Discriminating signal peptides from transmembrane regions. Nat. Methods 8, 785–786 (2011). [DOI] [PubMed] [Google Scholar]
  47. Caporaso J. G. et al. Qiime allows analysis of high-throughput community sequencing data. Nat. Methods 7, 335–336 (2010). [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Jungbluth S. P., Amend J. P. & Rappe M. S. Metagenome sequencing and 98 microbial genomes from juan de fuca ridge flank subsurface fluids. Sci. Data 4, 170037 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. Tamura K., Stecher G., Peterson D., Filipski A. & Kumar S. Mega6: Molecular evolutionary genetics analysis version 6.0. Mol. Biol. Evol 30, 2725–2729 (2013). [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Letunic I. & Bork P. Interactive tree of life (itol) v3: An online tool for the display and annotation of phylogenetic and other trees. Nucleic Acids Res. 44, W242–W245 (2016). [DOI] [PMC free article] [PubMed] [Google Scholar]
  51. Altschul S. F. et al. Gapped blast and psi-blast: A new generation of protein database search programs. Nucleic Acids Res 25, 3389–3402 (1997). [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Citations

  1. 2017. NCBI Sequence Read Archive. SRX3209014
  2. 2017. NCBI Sequence Read Archive. SRX3207342
  3. 2018. NCBI Sequence Read Archive. SRX4519345
  4. 2018. NCBI Sequence Read Archive. SRX4515224
  5. Chen B., et al. . 2018. figshare. https://doi.org/10.6084/m9.figshare.c.4249433.v1

Supplementary Materials

sdata2018285-isa1.zip (2.9KB, zip)

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