Repeatome Analyses and Satellite DNA Chromosome Patterns in Deschampsia sukatschewii, D. cespitosa, and D. antarctica (Poaceae)

Subpolar and polar ecotypes of Deschampsia sukatschewii (Popl.) Roshev, D. cespitosa (L.) P. Beauv, and D. antarctica E. Desv. are well adapted to stressful environmental conditions, which make them useful model plants for genetic research and breeding. For the first time, the comparative repeatome analyses of subpolar and polar D. sukatschewii, D. cespitosa, and D. antarctica was performed using RepeatExplorer/TAREAN pipelines and FISH-based chromosomal mapping of the identified satellite DNA families (satDNAs). In the studied species, mobile genetic elements of class 1 made up the majority of their repetitive DNA; interspecific variations in the total amount of Ty3/Gypsy and Ty1/Copia retroelements, DNA transposons, ribosomal, and satellite DNA were revealed; 12-18 high confident and 7-9 low confident putative satDNAs were identified. According to BLAST, most D. sukatschewii satDNAs demonstrated sequence similarity with satDNAs of D. antarctica and D. cespitosa indicating their common origin. Chromosomal mapping of 45S rDNA, 5S rDNA, and satDNAs of D. sukatschewii allowed us to construct the species karyograms and detect new molecular chromosome markers important for Deschampsia species. Our findings confirmed that genomes of D. sukatschewii and D. cespitosa were more closely related compared to D. antarctica according to repeatome composition and patterns of satDNA chromosomal distribution.

Automated summary

This study conducted a comparative repeatome analysis of subpolar and polar ecotypes of Deschampsia sukatschewii, revealing the genetic composition and chromosomal distribution patterns of satellite DNA. The findings provide new molecular chromosome markers for Deschampsia species.