Related Experiment Video

Updated: Sep 17, 2025

Genome-wide Analysis of Histone Modifications Distribution using the Chromatin Immunoprecipitation Sequencing Method in Magnaporthe oryzae
09:25

Genome-wide Analysis of Histone Modifications Distribution using the Chromatin Immunoprecipitation Sequencing Method in Magnaporthe oryzae

Published on: June 2, 2021

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Highly dynamic supernumerary mini-chromosomes in a Magnaporthe oryzae strain contributes to cellular variance of

Guifang Lin1, Huakun Zheng2, Dal-Hoe Koo3

  • 1Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA; Basic Forestry and Proteomics Research Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China.

Fungal Genetics and Biology : FG & B
|June 29, 2025
PubMed

Insights

Magnaporthe oryzae mini-chromosomes show high instability and frequent rearrangements, suggesting horizontal transfer and active retrotransposons contribute to fungal adaptability and pathogenicity in crops.

Area of Science:

  • Fungal genomics
  • Plant pathology
  • Molecular evolution

Background:

  • Magnaporthe oryzae causes devastating crop diseases and possesses genomic plasticity.
  • Supernumerary mini-chromosomes are dispensable, repetitive elements within M. oryzae strains.
  • Genomic plasticity, including mini-chromosomes, contributes to fungal adaptability and pathogenicity.

Purpose of the Study:

  • To investigate the stability and dynamics of mini-chromosomes in a Lolium strain (TF05-1) of M. oryzae.
  • To explore the potential horizontal transfer of mini-chromosomes between fungal isolates.
  • To characterize genomic rearrangements and retrotransposon activity within M. oryzae mini-chromosomes.

Main Methods:

  • Contour-clamped homogeneous electric field (CHEF) karyotyping to analyze mini-chromosome number and size variations.
  • Whole-genome sequencing to identify genomic polymorphisms and rearrangements.
  • Fluorescence in situ hybridization (FISH) for single-cell karyotyping and mini-chromosome quantification.
  • Bioinformatic analysis of Long Terminal Repeat (LTR) retrotransposons and methylation patterns.

Main Results:

  • Significant variation in mini-chromosome number and size was observed among progeny of the TF05-1 strain.
  • Evidence suggests horizontal transfer of a mini-chromosome between wheat and Lolium isolates.
  • Frequent intrachromosomal rearrangements, including deletions and duplications, were identified within mini-chromosomes.
  • LTR retrotransposons in mini-chromosomes are recently inserted, less methylated, and highly active, unlike those in core chromosomes.

Conclusions:

  • M. oryzae mini-chromosomes exhibit considerable instability and dynamic evolution.
  • Horizontal gene transfer and active retrotransposons likely drive mini-chromosome evolution and contribute to fungal pathogenicity.
  • Fungal genome defense mechanisms may be less effective against mini-chromosome elements, promoting their plasticity.
Keywords:
Blast diseaseGenome assemblyGenomic dynamicMagnaporthe oryzaeSupernumerary chromosomemini-chromosome

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