Methylated cytosines mainly prevail in intergenic regions, genomic repetitive elements, and highly copious transposable elements, such as long interspersed transposable elements (LINEs), short interspersed transposable elements (SINEs) and in endogenous retroviruses.
The soybean genome is about 1.1 Gb in size with the majority, 59%, consisting mostly of highly repetitive transposable elements [ 30].
These DMRs have very consistent methylation scores across all strains, and tend to correspond to highly methylated transposable elements or regions near centromeres.
The challenges of accurate gene prediction and enumeration are further aggravated in large genomes that contain highly repetitive transposable elements (TEs).
Consistent with the crucial role light plays in host-pathogen interactions between C. zeae-maydis and maize, we identified a large number of photoreceptors and light-regulated genes, plus Zephyr, a novel, highly expressed transposable element.
These elements were inserted after the divergence of the Silene sex chromosomes approximately 5 ~ 10 million years ago [ 12], which may be an indication of highly active transposable elements in the PAR.
Traditionally, horizontal transfer has been implied when highly similar transposable elements have been found in distantly related taxa accompanied by their discontinuous distribution, and such phenomenon could not be explained in terms of vertical inheritance [ 37- 39].
Helitrons represent a novel family of highly abundant transposable elements in the genomes of species representing all eukaryotic kingdoms (Kapitonov and Jurka 2001; Lal et al. 2003; Pritham and Feschotte 2007; Yang and Bennetzen 2009; Lal et al. 2009a, b).
Because of their highly repetitive sequence, transposable elements have previously been shown to undergo alternative splicing; this allows for full-length protein to be produced, albeit at reduced levels relative to those in WT controls [26], [27].
Retrotransposons represent a highly unique group of transposable elements and form large portions of the genomes of many eukaryotes (organisms with cells containing a clearly defined nucleus).
