Skip to main content

Table 1 Properties of different classes of genetic marker in terms of their qualitative suitability for use in molecular systematics studies 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 Nucleotide substitution saturationa Length of references in databaseb Easy alignment of sequences across wide phylogenetic rangeb Easy to design universal primersb
Nuclear rRNA 18S rRNA No Mostly partial No Yes
28S rRNA No Mostly partial No Yes
Nuclear spacer ITS1 Yes Mostly partial No No
ITS2 Yes Mostly partial No No
Mt protein-coding genes COI No Complete Yes No
COII No Complete Yes No
cytB No Complete Yes No
NAD1 No Complete Yes No
Mt rRNA 12S rRNA No Complete Yes Yes
16S rRNA No Complete Yes Yes
  1. CI, Confidence interval; Iss, simple index of substitution saturation; Iss.c, critical ISS; Mt, mitochondrial; SD, standard deviation; for other abbreviations, see Abbreviation List
  2. aSaturation was determined based on the sequence alignment used for each group of helminths. A ‘yes’ indicates saturation, with Iss > Iss.c
  3. bIndicates the same properties used for molecular identification