Project description:Transposable elements (TEs) play a pivotal role in shaping diversity in eukaryotic genomes. The covered smut pathogen on barley, Ustilago hordei, encountered a recent genome expansion. Using long reads, we assembled genomes of 6 U. hordei strains and 3 sister species, to study this genome expansion. We found that larger genome sizes can mainly be attributed to a higher genome fraction of long terminal repeat retrotransposons (LTR-RTs). In the studied smut genomes, LTR-RTs fractions are the largest in U. hordei and are positively correlated to the mating-type locus sizes, which is up to ~560 kb in U. hordei. Furthermore, LTR-RTs were found to be associated with higher nucleotide substitution levels, as these occur in specific genome regions of smut species with a recent LTR-RT proliferation. Moreover, genes in genome regions with higher nucleotide substitution levels generally reside closer to LTR-RTs than other genome regions. Genome regions with many nucleotide substitutions encountered an especially high fraction of CG substitutions, which is not observed for LTR-RT sequences. The high nucleotide substitution levels particularly accelerate the evolution of secretome genes, as their more accessory nature results that substitutions often lead to amino acid alterations.

2022-06-24 | GSE206526 | GEO

Comparative smut fungi project

Project description:Sequencing and comparative genomics of smut fungi

| PRJEB19641 | ENA

Evolutionary Strata in Mating-Type Chromosomes

Project description:Multiple evolutionary strata on young fungal mating-type chromosomes despite lack of sexual antagonism

| PRJEB15277 | ENA

Linkage of mating-type loci distinguishes bipolar from tetrapolar mating in basidiomycetous smut fungi.

Project description: Not available

| S-EPMC44343 | biostudies-other