Characterization of Chromosome-Specific Microsatellite Repeats and Telomere Repeats Based on Low Coverage Whole Genome Sequence Reads in Panax ginseng

Abstract

Repetitive DNA elements are ubiquitous in plant genomes. Although repeats provide relevant information for cytogenetic, evolutionary, and genomic studies, identifying and characterizing their sequence and chromosomal distribution are not always easily achieved through conventional methods. However, a high-throughput identification of genomic repeats can be obtained with short reads from next-generation sequencing data. Here, we identified the telomeric and two chromosome-specific repeats in Panax ginseng using low-coverage whole genome sequence data. The telomeric repeat sequence is same with the canonical angiosperm sequence, (TTTAGGG)n, and localized mostly in every chromosome termini, except for an additional interstitial location in chromosome 10. A dinucleotide (GA) microsatellite, PgGA15, with total genome representation (GR) of more than 33 kb localized in the long arm of chromosome 20. An 11-bp minisatellite, Pgms1, with more than 58 kb of GR localized in the long arm of chromosome 1. This study provides chromosome-specific markers for cytogenetic studies in P. ginseng.