SSR Marker Acquisition and Application from Transcriptome of Captive Chinese Forest Musk Deer (Moschus berezovskii)

Forest musk deer (Moschus berezovskii) is one of the most endangered medicinally important wild animals in the world. Forest musk deer farming is the main way of production of musk. However, the single provenance and lack of genetic information lead to reduced genetic diversity of forest musk deer. Therefore, more SSR markers need to be developed to identify forest musk deer germplasm. In this study, bone marrow derived mesenchymal cells were used to construct cDNA library for transcriptome sequencing. The datasets were de novo assembled and annotated. 9 polymorphic simple sequence repeat (SSR) markers were finally identified and used to detect population genetic diversity. 6.07 Gb clean data were generated using Illumina sequencing technology, and de novo assembled into 138,591 transcripts and 81,553 unigenes. 5,777 simple sequence repeats (SSRs) were identified, in which there were 578 repeating motif types, with mono-nucleotide and tri-nucleotides comprising 55.88% and 25.60%, respectively. 100 primer pairs were designed to validate amplification and polymorphism using DNA from fecal samples. 9 polymorphic SSRs were developed and used to detect population genetic diversity of 122 forest musk deer in 2 farms. The average number of alleles per locus varied from 4 to 15 (average = 8.3). The observed heterozygosity (H_O) per locus ranged from 0.102 to 0.941, while the expected heterozygosity (H_E) per locus was from 0.111 to 0.651. All loci deviated significantly from the Hardy-Weinberg equilibrium (p < 0.001). The polymorphism information content (PIC) of these loci varied from 0.108 to 0.619. 9 polymorphic SSR markers were developed in this research. These sites can be used for breeding planning and conservation of germplasm resources.