Scientists are increasingly overwhelmed by the volume of articles being published. The total number of articles indexed in Scopus and Web of Science has grown exponentially in recent years; in 2022 the article total was ∼47% higher than in 2016, which has outpaced the limited growth—if any—in the number of practicing scientists. Thus, publication workload per scientist has increased dramatically. We define this problem as “the strain on scientific publishing.” To analyze this strain, we present five data-driven metrics showing publisher growth, processing times, and citation behaviors. We draw these data from web scrapes, and from publishers through their websites or upon request. Specific groups have disproportionately grown in their articles published per year, contributing to this strain. Some publishers enabled this growth by hosting “special issues” with reduced turnaround times. Given pressures on researchers to “publish or perish” to compete for funding, this strain was likely amplified by these offers to publish more articles. We also observed widespread year-over-year inflation of journal impact factors coinciding with this strain, which risks confusing quality signals. Such exponential growth cannot be sustained. The metrics we define here should enable this evolving conversation to reach actionable solutions to address the strain on scientific publishing.
Antimicrobial peptides (AMPs) are host-encoded antibiotics that combat invading microorganisms. These short, cationic peptides have been implicated in many biological processes, primarily involving innate immunity. In vitro studies have shown AMPs kill bacteria and fungi at physiological concentrations, but little validation has been done in vivo. We utilized CRISPR gene editing to delete most known immune-inducible AMPs of Drosophila, namely: 4 Attacins, 2 Diptericins, Drosocin, Drosomycin, Metchnikowin and Defensin. Using individual and multiple knockouts, including flies lacking these ten AMP genes, we characterize the in vivo function of individual and groups of AMPs against diverse bacterial and fungal pathogens. We found that Drosophila AMPs act primarily against Gram-negative bacteria and fungi, contributing either additively or synergistically. We also describe remarkable specificity wherein certain AMPs contribute the bulk of microbicidal activity against specific pathogens, providing functional demonstrations of highly specific AMP-pathogen interactions in an in vivo setting.
This study advances current knowledge in the field of host-microbe interactions by demonstrating that the two families of immune effectors, antimicrobial peptides and lysozymes, actively regulate the gut microbiota composition and abundance. Consequences of the loss of these antimicrobial peptides and lysozymes are exacerbated during aging, and their loss contributes to increased microbiota abundance and shifted composition in old flies.
The melanization response is an important defense mechanism in arthropods. This reaction is mediated by phenoloxidases (POs), which are activated by complex extracellular serine protease (SP) cascades. Here, we investigate the role of SPs in the melanization response using compound mutants in D. melanogaster and discover phenotypes previously concealed in single-mutant analyses. We find that two SPs, Hayan and Sp7, activate the melanization response in different manners: Hayan is required for blackening wound sites, whereas Sp7 regulates an alternate melanization reaction responsible for the clearance of Staphylococcus aureus. We present evidence that Sp7 is regulated by SPs activating the Toll NF-κB pathway, namely ModSP and Grass. Additionally, we reveal a role for the combined action of Hayan and Psh in propagating Toll signaling downstream of pattern recognition receptors activating either Toll signaling or the melanization response.
Antimicrobial peptides are host-encoded immune effectors that combat pathogens and shape the microbiome in plants and animals. However, little is known about how the host antimicrobial peptide repertoire is adapted to its microbiome. Here, we characterized the function and evolution of the Diptericin antimicrobial peptide family of Diptera. Using mutations affecting the two Diptericins ( Dpt ) of Drosophila melanogaster , we reveal the specific role of DptA for the pathogen Providencia rettgeri and DptB for the gut mutualist Acetobacter . The presence of DptA- or DptB- like genes across Diptera correlates with the presence of Providencia and Acetobacter in their environment. Moreover, DptA- and DptB- like sequences predict host resistance against infection by these bacteria across the genus Drosophila . Our study explains the evolutionary logic behind the bursts of rapid evolution of an antimicrobial peptide family and reveals how the host immune repertoire adapts to changing microbial environments.