Table 5. Types of simple sequence repeats (SSR) identified in the gonadal transcriptome of the blood clam.
| Repeat motif | Number | Percentage (%) |
|---|---|---|
| Di-nucleotide | ||
| AC/CA/GT/TG | 347/348/424/378 | |
| AG/GA/CT/TC | 200/270/119/162 | |
| AT/TA/GC/CG | 872/800/0/1 | |
| Total | 3921 | 62.41% |
| Tri-nucleotide | ||
| AAC/AAG/AAT(N≥5) | 43/16/139 | |
| ACA/ACC/ACG/ACT | 40/22/3/2 | |
| AGA/AGC/AGG/AGT | 13/1/3/5 | |
| ATA/ATC/ATG/ATT | 95/34/48/88 | |
| CAA/CAC/CAG/CAT | 46/10/8/33 | |
| CCA/CCT/CGC | 16/4/1 | |
| CTA/CTC/CTG/CTT | 4/6/6/6 | |
| GAA/GAC/GAG/GAT | 20/3/6/48 | |
| GCA/GCT/GGA/GGT | 10/6/3/11 | |
| GTA/GTC/GTG/GTT | 3/2/12/18 | |
| TAA/TAC/TAG/TAT | 63/9/3/81 | |
| TCA/TCC/TCG/TCT | 52/4/3/14 | |
| TGA/TGC/TGG/TGT | 66/7/11/36 | |
| TTA/TTC/TTG | 108/15/36 | |
| Total | 1342 | 21.36% |
| Tetra-nucleotide | ||
| AAAC/AAAT | 3/9 | |
| AACA/AATA/AATC/AATT | 3/10/5/1 | |
| ACAG/ACAT/ACGC/ACTG | 1/2/1/1 | |
| AGAA/AGAT/AGTG | 1/1/1 | |
| ATAA/ATAC/ATAG/ATGT | 5/3/2/3 | |
| ATTA/ATTG/ATTT | 1/2/8 | |
| CAAA/CAAC/CTAT/CTGT | 1/2/1/1 | |
| GAAA/GAAT/GACA/GATA | 1/2/1/1 | |
| GTAT/GTCA/GTCC/GTCT | 1/1/1/2 | |
| GTGC/GTTG/GTTT | 1/1/1 | |
| TAAA/TAAT/TACA/TACT | 4/1/1/1 | |
| TATC/TATG/TATT | 3/2/6 | |
| TCAA/TCAT/TCTT | 1/2/1 | |
| TGAC/TGTA/TGTC | 1/1/2 | |
| TTAA/TTAT/TTGA/TTGT | 1/7/1/1 | |
| TTTA/TTTC/TTTG | 7/2/3 | |
| Total | 129 | 2.05% |
| Penta-nucleotide | ||
| AAAAT/AATCC/TGAGT | 1/1/1 | |
| CAAAG/CAGGC/CCAGC | 1/1/1 | |
| Total | 6 | 0.10% |
| Hexa-nucleotide | ||
| TTTTTC/TTATAA | 1/1 | |
| Total | 2 | 0.03% |
| others | 883 | 14.05% |
‘Number’ indicates the number of different types of SSR detected in unigenes while‘Percentage’ indicates the relative proportion of SSRs with different repeat motifs among the total number of SSRs.