Mega-sized pericentromeric blocks of simple telomeric repeats and their variants reveal patterns of chromosome evolution in ancient Cycadales genomes.

ABSTRACT: Simple telomeric repeats composed of six to seven iterating nucleotide units are important sequences typically found at the ends of chromosomes. Here we analyzed their abundance and homogeneity in 42 gymnosperm (29 newly sequenced), 29 angiosperm (one newly sequenced), and eight bryophytes using bioinformatics, conventional cytogenetic and molecular biology approaches to explore their diversity across land plants. We found more than 10 000-fold variation in the amounts of telomeric repeats among the investigated taxa. Repeat abundance was positively correlated with increasing intragenomic sequence heterogeneity and occurrence at non-telomeric positions, but there was no correlation with genome size. The highest abundance/heterogeneity was found in the gymnosperm genus Cycas (Cycadaceae), i

SUBMITTER: Vozarova R 

PROVIDER: S-EPMC9827991 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature