A network approach to investigate horizontal transfer across various bacterial mobile genetic elements

SémIdeev
 19/12/2025
 12:00:00
 Héloïse Muller, IBENS, Paris
 IDEEV - Salle Rachel Carlson

In bacteria, genetic material is carried by different molecular vehicles – one or few self-replicating chromosomes and a diverse array of mobile genetic elements (MGEs), such as phages, plasmids, transposons, and cassettes. MGEs are genetic agents that are capable of capturing DNA segments and moving them within and between cells. The clonal nature of bacteria is therefore disrupted by MGEs through horizontal transfer (HT). Hence, studying individual MGEs as independently evolving elements, rather than considering all MGEs as a homogenous consortium present inside a bacterium, will bring important insight to how MGEs contribute to the genetic diversity in populations.

In this sense, I will present two independent studies. In the first one, I investigated diverse MGE found in Listeria monocytogenes, an opportunistic foodborne pathogen responsible for listeriosis. In the second study, I focused on a particular MGE, the staphylococcal cassette chromosome mec (SCCmec), and I investigated the mechanisms governing its diversity across a large dataset of Staphylococcaceae. I will also shortly present some HT between animals, a phenomenon far less common in this taxon; yet recent work shows that animals can also transfer genetic material, through mechanisms still poorly understood.