Contrasting patterns of subtelomeric satellite superfamily in the Cannabaceae family

Satellite DNA (satDNA) is a rapidly evolving component of plant genomes, often found in centromeric, telomeric, and heterochromatic regions. Due to their variability and species- or population-specific distribution, satDNA serves as valuable cytogenetic markers for studying chromosomal rearrangements and karyotype evolution in closely related species. In dioecious species Cannabis sativa, Humulus lupulus, and Humulus japonicus, previous studies have identified species-specific subtelomeric repeats CS-1, HSR1, and HJSR. While these satellites have been used to differentiate sex chromosomes from autosomes, their evolutionary origins, sequence variation and pattern of conservation among related species remain largely unexplored. In this study, we combine bioinformatics analysis with molecular cloning to analyze sequence similarity among these shared satellites and determine their inter-specific chromosomal localization using fluorescence in situ hybridization (FISH). Our results reveal that HSR1 and HJSR satellites are shared among all studied species suggested oaring from a common ancestor. In contrast, CS-1 satellite exhibit higher sequence divergence. Although all satellites are predominantly localized in subtelomeric regions, CS-1 in H. lupulus and HSR in C. sativa are localized in pericentromeric regions. These findings provide new insight into the evolutionary dynamics of satDNA in Cannabaceae family and its role in genome organization.