Table 2 Properties of structural protein genes from two novel imported PRRSV sub-type strains, with relative synonymous codon usage analysis (Preferred codons, sub-types, and potential hosts are displayed in bold (mean value ± SD)

TTT(Phe)

1.330 ± 0.161

1.322 ± 0.186

1.339 ± 0.127

0.79

TTC(Phe)

0.670 ± 0.161

0.678 ± 0.186

0.661 ± 0.127

1.21

TTA(Leu)

0.441 ± 0.197

0.415 ± 0.193

0.470 ± 0.199

0.32

TTG(Leu)

2.009 ± 0.280

2.143 ± 0.280

1.859 ± 0.193

0.67

CTT(Leu)

0.965 ± 0.210

1.030 ± 0.217

0.893 ± 0.176

1.35

CTC(Leu)

0.865 ± 0.176

0.870 ± 0.199

0.860 ± 0.145

1.35

CTA(Leu)

0.383 ± 0.309

0.174 ± 0.225

0.616 ± 0.208

0.33

CTG(Leu)

1.335 ± 0.236

1.367 ± 0.280

1.300 ± 0.169

2.68

ATT(Ile)

1.170 ± 0.273

1.203 ± 0.313

1.132 ± 0.215

0.91

ATC(Ile)

1.334 ± 0.249

1.322 ± 0.291

1.347 ± 0.191

1.67

ATA(Ile)

0.496 ± 0.117

0.474 ± 0.138

0.520 ± 0.080

0.42

GTT(Val)

1.013 ± 0.190

0.971 ± 0.235

1.061 ± 0.104

0.57

GTC(Val)

1.442 ± 0.247

1.311 ± 0.253

1.588 ± 0.134

1.07

GTA(Val)

0.367 ± 0.175

0.453 ± 0.185

0.271 ± 0.097

0.34

GTG(Val)

1.175 ± 0.167

1.264 ± 0.177

1.076 ± 0.074

2.03

TCT(Ser)

0.724 ± 0.361

0.601 ± 0.353

0.862 ± 0.319

0.99

TCC(Ser)

1.556 ± 0.310

1.548 ± 0.332

1.564 ± 0.286

1.5

TCA(Ser)

0.952 ± 0.291

1.122 ± 0.204

0.762 ± 0.255

0.73

TCG(Ser)

0.428 ± 0.178

0.441 ± 0.215

0.413 ± 0.124

0.39

AGT(Ser)

0.389 ± 0.248

0.408 ± 0.196

0.368 ± 0.294

0.77

AGC(Ser)

1.956 ± 0.257

1.885 ± 0.255

2.036 ± 0.237

1.62

CCT(Pro)

2.355 ± 0.624

1.957 ± 0.536

2.800 ± 0.361

1.05

CCC(Pro)

0.471 ± 0.549

0.658 ± 0.619

0.261 ± 0.360

1.46

CCA(Pro)

0.728 ± 0.645

1.167 ± 0.528

0.238 ± 0.338

0.94

CCG(Pro)

0.448 ± 0.388

0.218 ± 0.401

0.706 ± 0.118

0.56

ACT(Thr)

1.114 ± 0.385

1.327 ± 0.249

0.877 ± 0.372

0.83

ACC(Thr)

2.035 ± 0.309

1.888 ± 0.260

2.198 ± 0.277

1.68

ACA(Thr)

0.511 ± 0.235

0.334 ± 0.152

0.709 ± 0.131

0.92

ACG(Thr)

0.341 ± 0.196

0.452 ± 0.144

0.218 ± 0.170

0.57

GCT(Ala)

0.583 ± 0.275

0.758 ± 0.230

0.387 ± 0.169

0.96

GCC(Ala)

1.430 ± 0.329

1.207 ± 0.216

1.679 ± 0.244

1.8

GCA(Ala)

0.477 ± 0.314

0.662 ± 0.279

0.271 ± 0.202

0.74

GCG(Ala)

1.511 ± 0.266

1.372 ± 0.230

1.666 ± 0.213

0.5

TAT(Tyr)

1.211 ± 0.244

1.176 ± 0.203

1.249 ± 0.279

0.73

TAC(Tyr)

0.789 ± 0.244

0.824 ± 0.203

0.751 ± 0.279

1.27

CAT(His)

1.242 ± 0.286

1.321 ± 0.316

1.152 ± 0.216

0.7

CAC(His)

0.758 ± 0.286

0.679 ± 0.316

0.848 ± 0.216

1.3

CAA(Gln)

1.249 ± 0.271

1.294 ± 0.326

1.199 ± 0.182

0.44

CAG(Gln)

0.751 ± 0.271

0.706 ± 0.326

0.801 ± 0.182

1.56

AAT(Asn)

0.896 ± 0.159

0.886 ± 0.183

0.907 ± 0.126

0.79

AAC(Asn)

1.104 ± 0.159

1.114 ± 0.183

1.093 ± 0.126

1.21

AAA(Lys)

1.385 ± 0.250

1.273 ± 0.243

1.511 ± 0.192

0.76

AAG(Lys)

0.615 ± 0.250

0.727 ± 0.243

0.489 ± 0.192

1.24

GAT(Asp)

0.846 ± 0.280

0.987 ± 0.232

0.689 ± 0.245

0.8

GAC(Asp)

1.154 ± 0.280

1.013 ± 0.232

1.311 ± 0.245

1.2

GAA(Glu)

0.624 ± 0.207

0.564 ± 0.233

0.690 ± 0.148

0.72

GAG(Glu)

1.376 ± 0.207

1.436 ± 0.233

1.310 ± 0.148

1.28

TGT(Cys)

0.838 ± 0.176

0.927 ± 0.159

0.738 ± 0.137

0.79

TGC(Cys)

1.162 ± 0.176

1.073 ± 0.159

1.262 ± 0.137

1.21

CGT(Arg)

1.268 ± 0.675

0.867 ± 0.417

1.716 ± 0.626

0.44

CGC(Arg)

0.785 ± 0.524

1.090 ± 0.386

0.444 ± 0.442

1.31

CGA(Arg)

0.178 ± 0.305

0.134 ± 0.308

0.227 ± 0.296

0.6

CGG(Arg)

1.340 ± 0.204

1.327 ± 0.218

1.354 ± 0.188

1.29

AGA(Arg)

1.512 ± 0.402

1.677 ± 0.447

1.328 ± 0.235

1.12

AGG(Arg)

0.918 ± 0.388

0.905 ± 0.385

0.933 ± 0.394

1.23

GGT(Gly)

1.281 ± 0.435

1.580 ± 0.322

0.947 ± 0.270

0.57

GGC(Gly)

1.487 ± 0.416

1.182 ± 0.259

1.828 ± 0.266

1.46

GGA(Gly)

0.272 ± 0.182

0.250 ± 0.201

0.297 ± 0.156

0.91

GGG(Gly)

0.960 ± 0.183

0.989 ± 0.215

0.929 ± 0.132

1.05