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Table 2 Properties of different classes of genetic marker in terms of their quantitative suitability for molecular systematics of helminths

From: Assessing the suitability of mitochondrial and nuclear DNA genetic markers for molecular systematics and species identification of helminths

Class of marker Genetic marker Nematodesa Trematodesa Cestodesa
Mean ± SD [95 CI%] Recovered orders as monophyleticb Mean ± SD [95 CI%] Recovered suborders as monophyleticb Mean ± SD [95 CI%] Recovered orders as monophyleticb
Nuclear rRNA 18S rRNA 0.029* ± 0.019 [0.024–0.034] 3/6 0.036* ± 0.015 [0.033–0.038] 3/4 0.039* ± 0.021 [0.039–0.043] 4/6
28S rRNA 0.050* ± 0.026 [0.039–0.061] 3/6 0.120* ± 0.049 [0.116–0.124] 3/4 NA 4/6
Nuclear spacer ITS1 0.356 ± 0.227 [0.287–0.425] 0/6 0.262 ± 0.115 [0.2478–0.277] 3/4 0.546* ± 0.198 [0.481–0.612] 2/3
ITS2 0.537* ± 0.222 [0.429–0.644] 3/6 0.171 ± 0.078
[0.160–0.181]
3/4 0.550* ± 0.106 [0.491–0.609] 5/5
Mt protein-coding COI 0.215 ± 0.103 [0.197–0.234] 3/6 0.264 ± 0.047 [0.258–0.271] 2/4 0.136 ± 0.056 [0.127–0.146] 5/6
COII 0.249 ± 0.139 [0.224–0.274] 4/6 0.359 ± 0.069 [0.345–0.364] 2/4 0.179 ± 0.075 [0.167–0.191] 4/5
cytB 0.249 ± 0.097 [0.232–0.267] 3/6 0.259 ± 0.040 [0.254–0.265] 1/4 0.183 ± 0.080 [0.170–0.197] 5/5
NAD1 0.232 ± 0.100 [0.214–0.250] 5/6 0.289 ± 0.052 [0.282–0.296] 2/4 0.193 ± 0.066 [0.982–0.203] 6/6
Mt rRNA 12S rRNA 0.198 ± 0.106 [0.178–0.217] 4/6 0.272 ± 0.055 [0.265–0.280] 2/4 0.140 ± 0.063 [0.129–0.150] 5/6
16S rRNA 0.227 ± 0.091 [0.2109–0.244] 4/6 0.264 ± 0.051 [0.257–0.271] 3/4 0.149 ± 0.072 [0.137–0.160] 5/6
  1. NA, No data available
  2. *Statistically significant difference of the mean genetic distances between the markers at P < 0.000001), according to Kruskal–Wallis test with Dunn’s posthoc analysis
  3. aGenetic distances among nematodes (Ascaridida and Spirurida), trematodes (Opisthorchiata, Echinostomata and Xiphidata), and cestodes (Taeniidae and Hymenolepididae) were used to calculate mean genetic distances
  4. bThe number of orders/suborders recovered as monophyletic out of the total number of recognized orders/suborders represented among available sequences (6 for nematodes, 4 for trematodes, 6 for cestodes)