Forum for Science, Industry and Business

Bacteria use their enemy -- phage -- for 'self-recognition'

Recently, scientists discovered that cells can distinguish themselves from closely related competitors through the use of a virus, and the harboring of phage in bacterial genomes benefits host cells when facing competitors in the environment. These findings were published in Cell Reports on April 16.

Demarcation lines (shown by red arrows) developed between cells of self and of non-self.

Credit: WANG Xiaoxue

The study was conducted by a group led by Prof. WANG Xiaoxue at the South China Sea Institute of Oceanology (SCSIO) of the Chinese Academy of Sciences and Prof. Thomas Wood at Pennsylvania State University in the United States.

Researchers found that a boundary (demarcation line) was formed due to phage lysis between different swimming Escherichia coli strains but not between identical clones; hence, motile bacterial cells discriminated between self and non-self.

The basis for this self-recognition is a novel, 49 kb, T1-type, lytic phage of the family Siphoviridae (named SW1) that controls formation of the demarcation line by utilizing one of the host's cryptic prophage proteins, YfdM of CPS-53, to propagate.

SW1 provides a conditional benefit to E. coli K-12 compared to the identical strain that lacks the phage. A demarcation line also forms when strains harbor either the lysogenic phage φ80 or lambda and encounter siblings that lack the lysogen.

Thus, the relationship between a virus and its cellular host should be re-evaluated since a viral infection is sometimes beneficial.

A bacterial cell infected by a lytic phage may have conditional benefits absent in siblings that lack the phage. In addition, these benefits rely on the infected strain utilizing the tools it obtained from a very ancient enemy, a cryptic prophage.

WANG Xiaoxue | EurekAlert!
Further information:
http://dx.doi.org/10.1016/j.celrep.2019.03.070

Im Focus: Cheers! Maxwell's electromagnetism extended to smaller scales

More than one hundred and fifty years have passed since the publication of James Clerk Maxwell's "A Dynamical Theory of the Electromagnetic Field" (1865). What would our lives be without this publication?

It is difficult to imagine, as this treatise revolutionized our fundamental understanding of electric fields, magnetic fields, and light. The twenty original...

Im Focus: Highly charged ion paves the way towards new physics

In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.

Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...

Im Focus: Ultrafast stimulated emission microscopy of single nanocrystals in Science

The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...

Im Focus: How to induce magnetism in graphene

Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...

Im Focus: Electronic map reveals 'rules of the road' in superconductor

Band structure map exposes iron selenide's enigmatic electronic signature

Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...