AUTHOR=Kuo Yi-Tzu , Ishii Takayoshi , Fuchs Jörg , Hsieh Wei-Hsun , Houben Andreas , Lin Yann-Rong 

TITLE=The Evolutionary Dynamics of Repetitive DNA and Its Impact on the Genome Diversification in the Genus Sorghum

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.729734

DOI=10.3389/fpls.2021.729734

ISSN=1664-462X

ABSTRACT=<p>Polyploidization is an evolutionary event leading to structural changes of the genome(s), particularly allopolyploidization, which combines different genomes of distinct species. The tetraploid species, <italic>Sorghum halepense</italic>, is assumed an allopolyploid species formed by hybridization between diploid <italic>S. bicolor</italic> and <italic>S. propinquum</italic>. The repeat profiles of <italic>S. bicolor</italic>, <italic>S. halepense</italic>, and their relatives were compared to elucidate the repeats’ role in shaping their genomes. The repeat frequencies and profiles of the three diploid accessions (<italic>S. bicolor</italic>, <italic>S. bicolor</italic> ssp. <italic>verticilliflorum</italic>, and <italic>S. bicolor</italic> var. <italic>technicum</italic>) and two tetraploid accessions (<italic>S. halepense</italic>) are similar. However, the polymorphic distribution of the subtelomeric satellites preferentially enriched in the tetraploid <italic>S. halepense</italic> indicates drastic genome rearrangements after the allopolyploidization event. Verified by CENH3 chromatin immunoprecipitation (ChIP)-sequencing and fluorescence <italic>in situ</italic> hybridization (FISH) analysis the centromeres of <italic>S. bicolor</italic> are mainly composed of the abundant satellite SorSat137 (CEN38) and diverse CRMs, Athila of Ty3_gypsy and Ty1_copia-SIRE long terminal repeat (LTR) retroelements. A similar centromere composition was found in <italic>S. halepense</italic>. The potential contribution of <italic>S. bicolor</italic> in the formation of tetraploid <italic>S. halepense</italic> is discussed.</p>