Three-dimensional genome architecture connects chromatin structure and function in a major wheat pathogen

Area of Science:

• Genomics
• Molecular Biology
• Mycology

Background:

• Genome spatial organization is crucial for biological function, but poorly understood in filamentous fungi.
• Zymoseptoria tritici, a wheat pathogen, has a unique compartmentalized genome with core and accessory chromosomes.
• This study investigates the 3D genome architecture of Z. tritici, a model for genome evolution.

Purpose of the Study:

• To present the first 3D genome analysis of a eukaryotic organism with numerous accessory chromosomes.
• To reveal the hierarchical genome architecture integrating core and accessory regions in Z. tritici.
• To understand the functional relevance of nuclear architecture in filamentous fungi.

Main Methods:

• 3D genome analysis
• Microscopy-based techniques
• Chromatin interaction analysis

Main Results:

• Centromere clustering defines global genome conformation, with accessory chromosomes segregated but interacting with core regions for stability.
• Homotypic interactions occur within heterochromatin, and self-interacting domains are marked by specific histone modifications and gene expression.
• Transposon-rich heterochromatic domains show strong inter-domain interactions, linking 3D architecture to dynamic gene regulation during infection.

Conclusions:

• The study uncovers multi-scale principles of nuclear organization in a major fungal plant pathogen.
• Hierarchical nuclear architecture contributes to gene expression coordination and genome stability.
• Establishes a framework for studying 3D genome function and chromatin regulation in filamentous fungi and other microbes.