Distribution and Comparative Analysis of Genomic Microsatellites in Nine Species of Family Sillaginidae

We conducted a comparative analysis of the identified microsatellite sequences across the genomes of nine sillaginids. We examined the microsatellites with motifs ranging from 1 to 6 bp in length and analyzed their distribution and frequency across different genomic regions. Microsatellite occurrence differed significantly with the degree of coverage ranging from 1.47 to 3.21%. The number and proportion of each repeat type were consistent across the nine species, with di-nucleotide repeats being the most abundant, followed by mono-nucleotide repeats, and gradually decreasing as the number of repeat units increased. The mono-nucleotide repeat motifs were dominated by A/T, while di-nucleotide repeat motifs were mainly AC/GT, and tri-nucleotide repeat motifs were primarily AGG/CCT. Regarding the number of repeats, microsatellites in Sillaginidae were generally concentrated between 5 and 18 repeat units, with peaks observed at 6 and 10 repetitions. The abundance of microsatellite loci consistently decreased as the number of repetitions increased beyond 10. These findings provide valuable insights into genome evolution and microsatellite DNA dynamics, supporting future investigations into their structural and functional characteristics, compositional patterns, and applications in molecular marker development for these species.