Source/description: We identified a total of 21 781 equine microsatellites on the second horse genome assembly Equ-Cab2.0 (Table S1), which can be accessed at http://www. tiho-hannover.de/einricht/zucht/index.htm. These microsatellites cover the horse genome with a mean distance of 112 kb and a median distance of 75 kb (Table S2). Most of the repeat motifs (72%) were dinucleotide repeats of AC, GT and AT with frequencies of 26.4%, 26.0% and 19.4%. Trinucleotide repeats represented 3.8%, tetranucleotide repeats 17.6% and pentanucleotide repeats 1.6% of all simple sequence repeats (SSR). We identified adjacent SINE and LINE elements and the corresponding gene ID for 5549 (25.5%) intragenic microsatellites. Primer pairs were designed for 12 246 microsatellites after masking repetitive elements.Identification of microsatellites and their assignment on the horse genome: Permutation sequences including all repeat motifs of two to five bases with at least 15 and up to 30 repeats were generated for the search of EquCab2.0. We then employed a stand-alone BLAST with the Blastn mode (ftp://ftp.ncbi.nih.gov/ blast/executable/) with maximum e-values of e )6 to e )10 for alignment of the permutated SSRs with di-, tri-, tetra-or pentanucleotide sequences. The maximum number of repeat motifs was set at 30 for two to four bases and at 15 for five bases.PCR-primers: Primer pairs were designed using PRIMER3 (version 0.4.0,