English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  Identification and mapping of repetitive elements is a key step for accurate gene prediction and overall structural annotation of genomes. During the assembly and annotation of three highly repetitive amoeba genomes,  Entamoeba histolytica ,  Entamoeba dispar , and  Entamoeba invadens , we performed comparative sequence analysis to identify and map all class I and class II transposable elements in their sequences.    Results  Here, we report the identification of two novel  Entamoeba -specific repeats: ERE1 and ERE2; ERE1 is spread across the three genomes and associated with different repeats in a species-specific manner, while ERE2 is unique to  E. histolytica . We also report the identification of two novel subfamilies of LINE and SINE retrotransposons in  E. dispar  and provide evidence for how the different LINE and SINE subfamilies evolved in these species. Additionally, we found a putative transposase-coding gene in  E. histolytica  and  E. dispar  related to the  mariner  transposon  Hydargos  from  E. invadens . The distribution of transposable elements in these genomes is markedly skewed with a tendency of forming clusters. More than 70% of the three genomes have a repeat density below their corresponding average value indicating that transposable elements are not evenly distributed. We show that repeats and repeat-clusters are found at syntenic break points between  E. histolytica  and  E. dispar  and hence, could work as recombination hot spots promoting genome rearrangements.    Conclusion  The mapping of all transposable elements found in these parasites shows that repeat coverage is up to three times higher than previously reported. LINE, ERE1 and  mariner  elements were present in the common ancestor to the three  Entamoeba  species while ERE2 was likely acquired by  E. histolytica  after its separation from  E. dispar . We demonstrate that  E. histolytica  and  E. dispar  share their entire repertoire of LINE and SINE retrotransposons and that Eh_SINE3/Ed_SINE1 originated as a chimeric SINE from Eh/Ed_SINE2 and Eh_SINE1/Ed_SINE3. Our work shows that transposable elements are organized in clusters, frequently found at syntenic break points providing insights into their contribution to chromosome instability and therefore, to genomic variation and speciation in these parasites.

Genome wide survey, discovery and evolution of repetitive elements in three Entamoeba species