BackgroundSpounavirinae viruses have received an increasing interest as tools for the control of harmful bacteria due to their relatively broad host range and strictly virulent phenotype.ResultsIn this study, we collected and analyzed the complete genome sequences of 61 published phages, either ICTV-classified or candidate members of the Spounavirinae subfamily of the Myoviridae. A set of comparative analyses identified a distinct, recently proposed Bastille-like phage group within the Spounavirinae. More importantly, type 1 thymidylate synthase (TS1) and dihydrofolate reductase (DHFR) genes were shown to be unique for the members of the proposed Bastille-like phage group, and are suitable as molecular markers. We also show that the members of this group encode beta-lactamase and/or sporulation-related SpoIIIE homologs, possibly questioning their suitability as biocontrol agents.ConclusionsWe confirm the creation of a new genus—the “Bastille-like group”—in Spounavirinae, and propose that the presence of TS1- and DHFR-encoding genes could serve as signatures for the new Bastille-like group. In addition, the presence of metallo-beta-lactamase and/or SpoIIIE homologs in all members of Bastille-like group phages makes questionable their suitability for use in biocontrol.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1757-0) contains supplementary material, which is available to authorized users.
Daphnia magna is a keystone indicator
zooplankton used in environmental quality assessments. Comparative
metabolomics, which contrasts small biomolecular regulations under
different conditions, has emerged as a sensitive and informative investigation
tool for the assessment of environmental stressors on D. magna. Baseline metabolomic variation is likely
impacted by the asexual reproduction cycle of D. magna; however, the relationship between metabolite concentration regulation
and reproduction cycle has not been investigated. This study investigated
the time-course regulation of 51 metabolites during different reproduction
stages to determine how the reproduction cycle controlled the metabolite
profile of D. magna. Two-way analysis
of variance (ANOVA) results reveal that most metabolites show significantly
differentiated concentrations by individual or a combination of reproduction
stages and sampling time. On the basis of the partial least-squares-discriminant
analysis (PLS-DA) and ANOVA-simultaneous component analysis (ANOVA-SCA),
stages 2 and 3 of reproduction show similarity in metabolite abundance
regulation compared to stage 1. Metabolites were classified as being
either dependent or independent of reproduction in the pairwise concentration
correlation based on Pearson correlation coefficients. This study
observed that the D. magna reproduction
stage is an important consideration and potential variable and should
be considered carefully when conducting metabolomic experiments using D. magna.
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