Vivien Joisten-Rosenthal

@vivienrosenthal.bsky.social

Phd student at HHU Institute for Biological Data Science | Focusing on lichen metagenomics, plant genomics and other cool stuff

8/8 Thus, pathogenic and mutualistic fungi might share a genomic grammar-compartmentalized genomes, mobile-element-driven diversification, and expanded recognition & signaling repertoires. Is this just an ancestral genomic toolkit - with ecology deciding the outcome or is there yet more to discover?

7/8 Does the genomic toolkit actually get used? Layer-specific RNA-seq of a P. rufescens thallus seems to indicate so: Pth11 GPCRs, peptidase antimicrobial proteins and a LEC-1-like galectin all light up in the cortex/photobiont layer - the symbiotic interface.

Gene expression in different Peltigera layers

6/8 Structure-based search finds ~103 GPCRs per genome - vs 26 with old sequence methods in Cladonia. 76% are Pth11-like (CFEM) receptors. These are often found in plant pathogens as well …the plot thickens further.

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5/8 But there is more lichens as an untapped antimicrobial reservoir? ~306 antimicrobial candidate proteins per genome on average. Profiles are species-specific and remarkably stable, with lineage-specific expansions and the tripartite species carry the biggest catalogues.

4/8 And lurking in those plastic, repeat-rich regions: Starship-like elements - sometimes close to virulence-associated orthologs. Big mobile elements doing their big mobile-element things.

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3/8 But there seems to be a pathogen parallel we didn't really expect in a mutualist: secreted-protein genes sit significantly closer to transposable elements than other genes in the genomes. That looks like the "two-speed genome" of plant pathogens… in a lichen.