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Leh, H.

Publications and source records attributed to Leh, H..

2 recordsLinked to original sources
bioRxiv2023

Phage-mediated dispersal of multicellular bacteria

Streptomyces are renowned for their prolific production of specialized metabolites with applications in medicine and agriculture. These multicellular bacteria present a sophisticated developmental cycle, and play a key role in soil ecology. Little is known about Streptomyces-phage interactions and the impact of phages on Streptomyces physiology. In this study, we investigated the conditions governing the expression and production of Samy, a prophage found in Streptomyces ambofaciens ATCC 23877. This siphoprophage is produced simultaneously with the activation of other mobile genetic elements. We show that Samy production increases bacterial dispersal under in vitro stress conditions. Altogether, we unveiled a new property of a bacteriophage infection that it is closely linked to the multicellular community life of Streptomyces bacteria. Graphical summary O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=163 SRC="FIGDIR/small/549817v2_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@126b3fcorg.highwire.dtl.DTLVardef@1f26808org.highwire.dtl.DTLVardef@18bfdcforg.highwire.dtl.DTLVardef@1c44be3_HPS_FORMAT_FIGEXP M_FIG C_FIG IMPORTANCEStreptomyces are multicellular bacteria producing valuable metabolites, including antibiotics, with applications in medicine and agriculture. In this study, we characterized a novel temperate phage, named Samy, and its impact on bacteria physiology. Remarkably, the presence and production of Samy increases bacterial dispersal under in vitro stress conditions. This constitutes an emerging property associated with bacteriophage infection that might enhance the spread of the species. Our study reveals a new aspect of bacteriophage infection in the context of multicellular aggregate dynamics.

microbiology↗
bioRxiv2020

Dynamics of the compartmentalized Streptomyces chromosome during metabolic differentiation

Streptomyces are among the most prolific bacterial producers of specialized metabolites, including antibiotics. The linear chromosome is partitioned into a central region harboring core genes and two extremities enriched in specialized metabolite biosynthetic gene clusters (SMBGCs). The molecular mechanisms governing structure and function of these compartmentalized genomes remain mostly unknown. Here we show that in exponential phase, chromosome structure correlates with genetic compartmentalization: conserved, large and highly transcribed genes form boundaries that segment the central part of the chromosome into domains, whereas the terminal ends are transcriptionally, largely quiescent compartments with different structural features. Onset of metabolic differentiation is accompanied by remodeling of chromosome architecture from an open to a rather closed conformation, in which the SMBGCs are expressed forming new boundaries. Altogether, our results reveal that S. ambofaciens linear chromosome is partitioned into structurally distinct entities, indicating a link between chromosome folding, gene expression and genome evolution.

microbiology↗