Evolution of piggyBac Transposons in Apoidea

In this study, we investigated the presence of ( ) transposons in 44 bee genomes from the Apoidea order, which is a superfamily within the Hymenoptera, which includes a large number of bee species crucial for pollination. We annotated the transposons in these 44 bee genomes and examined their evolution profiles, including structural characteristics, distribution, diversity, activity, and abundance. The mined transposons were divided into three clades, with uneven distribution in each genus of transposons in Apoidea. The complete transposons we discovered are around 2.23-3.52 kb in length and encode transposases of approximately 580 aa, with terminal inverted repeats (TIRs) of about 14 bp and 4 bp (TTAA) target-site duplications. Long TIRs (200 bp, 201 bp, and 493 bp) were also detected in some species of bees. The DDD domains of the three transposon types were more conserved, while the other protein domains were less conserved. Generally, most transposons showed low abundance in the genomes of Apoidea. Divergent evolution dynamics of were observed in the genomes of Apoidea. transposons in some identified species were relatively young, whiles others were older and with some either active or inactive. In addition, multiple invasions of were also detected in some genomes of Apoidea. Our findings highlight the contribution of transposons to genomic variation in these species and suggest their potential as candidates for future gene transfer tools.