Genomic differentiation of Deschampsia antarctica and D. cespitosa (Poaceae) based on satellite DNA

GONZÁLEZ MARÍA LAURA; CHIAPELLA JORGE; TOPALIAN JULIANA; URDAMPILLETA JUAN DOMINGO

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2020

0024-4074

Repetitive DNA is a fast evolving component of vascular plants genomes, which can account for genomic differentiation in plant lineages. One kind of repetitive DNA is the satellite DNA (satDNA), which consists of sequence monomers tandemly repeated forming big arrays. SatDNA sequence, array size and disposition on chromosomes may vary between reproductive isolated groups, as different populations or closely related species. Deschampsia is a cosmopolitan grass genus growing in temperate and cold regions; Deschampsia cespitosa is widespread all over the world, while D. antarctica is restricted to Antarctica and southern Patagonia. The present work aims to the identification, isolation and comparison of satDNA from the genomes of two species of Deschampsia with bioinformatics tools and their subsequent analysis and cytological study. The genomic analysis of TAREAN found 34 families of satDNA included on 21 superfamilies, most of them shared between the two species. Certain of these satDNAs presented homology with other previously reported on grasses. Some satDNAs were exclusively found on one of the two species; most of satDNAs of both species resulted similar, with differences in composition and abundance. However, the chromosome hybridization patterns of many satDNAs were different between both species, highlighting the importance of changes in genome disposition of satDNA in the evolution of these taxa. Based on the ?satDNA library hypothesis? the differential amplification of satDNAs between independent lineages may be the cause of such differences.