Origin of non-autonomous transposons

In yeast mitochondrial genome, AT nucleotides account for up to 85% of whole genome. In contrast to the AT rich genome, many GC-rich fragments were found. I have observed compelling evidence of these GC clusters propagating within the AT-rich mitochondrial genome. The GC clusters experience rapid diversification by nucleotide substitution and, more importantly, undergo dynamic mergers and shuffling to form new mobile elements. (Wu et al 2015)

Horizontal transfer in yeast mitochondrial genome

HGT was long thought to be rare in mitochondrial DNA. With the surprising discovery of frequent and sometimes massive mitochondrial HGT in certain plant species, it becomes important to determine the prevalence and significance of mitochondrial HGT in other eukaryotes. I showed compelling evidence for extensive homologous recombination-mediated, mitochondrial-to-mitochondrial horizontal transfer occurring throughout yeast mitochondrial genomes, including intron and protein coding genes. This transfer has led to substantial intraspecific polymorphism in both sequence content and sequence divergence. (Wu et al 2015)

 Horizontal transfer and homologous recombination    shaping the landscape of mitochondrial introns

Up to 25% of yeast mitochondrial genome is composed of introns, and most mitochondrial introns are group I introns. The group I introns distribute sporadically within and between species, which have been thought to be derived by homing endonuclease genes (HEGs). Our results suggest that recurrent gene conversion following horizontal transfer could serve as an excellent mechanism facilitate intron gain and loss independent of HEG function. This is exciting data that changes common views on group I intron mobility and dynamics. (Wu et al 2014)