Identification Of Active Transposable Elements In The Genome Of Bombus Terrestris

Transposable elements are the main sequence components of eukaryotic genomes,which has a significant impact on the structure,function and evolution of eukaryotic genomes.Active transposons are inserted into the promoters,exons,introns and 5’,3’ regions of genes to change or destroy gene expression,thereby producing mutants.In terrestrial ecosystems,pollinating insects play an extremely important role.Especially bees,they are the main pollinators of global crops.Pollination by bees can significantly increase the yield of crops and improve the quality of agricultural products,which has extraordinary meaning to agricultural production.As a member of the honeybee family,bumblebees are widely focused on because of their great role in pollination of greenhouse crops.Although researches on insect transposons are increasing,and scientists have successfully used transposons to excavate functional genes in recent years,relevant studys only pay attention to Diptera fruit flies,thus there is currently no high-efficiency functional gene mining system in bumblebee.We used bioinformatics methods,based on two strategies of de novo prediction and structure prediction,to identify,classify and annotate the transposons in the bumblebee reference genome in detail,and identify potentially active transposons.The results showed that although the transposon sequence only accounted for 3.74% of the total sequence of the bumblebee genome,there were many kinds of superfamily.The 33282 transposons identified belonged to 22 superfamily.A potentially active MITE transposon sequence was identified by bioinformatics methods,and it is likely to be transposed in the Bumblebee genome.Second,using population genomics methods to detect the polymorphic loci of this MITE in the population.The results showed that in the same population of 19 male bumblebees,this MITE had 21 polymorphic loci.Most MITE sequences tend to be inserted into the AT region and the promoter region of genes.Finally,using 36 male bees from the same population to perform PCR verification on 21 polymorphic loci,a polymorphic band was verified.This site locates in the promoter region of the gene encoding lnc RNA.This study systematically analyzed the composition,classification,and identification of potentially active transposons in the bumblebee genome from three levels: bioinformatics,population genomics,and molecular biology experimental verification.Through these analyses,we determined that a MITE in the bumblebee genome should be an active transposon.The active transposon identified in this study will lay an important foundation for the creation of a mutant library of bumblebees and the discovery of bumblebee functional genes.