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bioRxiv · 10.1101/2022.04.17.488575

Diversity chromosome evolution of Ty1-copia Retrotransposons in Pennisetum purpureum Revealed by FISH

Yu, Z. h.·Huang, Y. j.·Li, X. t.·Wu, J. y.·Zhang, M. q.·Deng, Z. h.
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Abstract

Pennisetum purpureum is a potential species for biofuel production. Characterization and chromosomal distribution of retrotransposons could enhance the comprehension of the role and dynamics of the repetitive elements in plants. In this study, a phylogenetic tree was constructed according to the conserved reverse transcriptase sequences and revealed that these Ty1-copia retrotransposons had typical structure. Analysis showed that total Ty1-copia retrotransposons had a significant component, as high as 5.12 x 103 copy numbers in P. purpureum. Then, the chromosomal pattern of four known lineages were also analyzed with Pennisetum glaucum genome, which suggested that the Sire/Maximus lineage had the highest copy number and followed by Tork/Angela, Tork/TAR, Retrofit/Ale. Additionally, the chromosomal distribution of total Ty1-copia retrotransposons was detected by fluorescence in situ hybridization (FISH) to be a dispersed pattern with weak clustering, mostly near the centromeric regions of P. purpureum chromosomes; interestingly, there were four obvious signals in the subterminal chromosomes. These results suggested that there occurred differential dynamic evolution directions of Ty1-copia retrotransposons within P. purpureum. Furthermore, co-localization of Ty1-copia, 5S rDNA, and 35S rDNA indicated that two chromosome 2 and four chromosome 4 were identified. Concurrently, subterminal signals of Ty1-copia-type retrotransposons were located on four other homologous chromosomes. Altogether, these results shed light on the diversification of Ty1-copia retrotransposons and have the significance for generation of valid chromosomal markers in retrotransposon families.

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Yu, Z. h., Huang, Y. j., Li, X. t., Wu, J. y., Zhang, M. q., Deng, Z. h.. 2022-04-18. Diversity chromosome evolution of Ty1-copia Retrotransposons in Pennisetum purpureum Revealed by FISH. https://doi.org/10.1101/2022.04.17.488575

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