Up to now a multitude of molecular markers have been developed for detection or identification of trematode
species. Many base on the internal transcribed spacers of ribosomal DNA (ITS). These sequences are quite similar in
the genome of related species, which makes it very easy to analyze them and design primers for distinguishing
between certain species. Other attempts base on neutral tandem repeated sequences, that are not under selective
pressure. They are present in very high copy numbers which offers the possibility to detect traces
of DNA of a certain species. They also evolve more rapidly than ITS sequences, offering a greater chance to
find species specific differences.
In cooperation with Joseph Hamburger (Haddash Medical School, Jerusalem, Israel) we started to look for tandem repeated
sequences, that are suitable to design specific PCR primers for the detection of larval stages in snail and
plankton samples. A specific detection will open avenues for ecological research on trematode larval stages in
the field, where many organisms hinder microscopic examination. We already developed primers for
Trichobilharzia spp. and E. caproni. Together with the primers of
Hamburger et al. they are now employed for the
analysis of samples from semi-filed experiments on the transmission and ecology of Trichobilharzia ocellata,
Schistosoma mansoni and Echinostoma caproni miracidia.
| Primers for the amplification of neutral tandem repeated sequences of trematodes. | |||
| Forward Primer | Reverse Primer | Species | Author |
| GACGACAATAGTTGGGGTG | GAATGGTATACGAGCTTGCC | Echinostoma caproni | HERTEL J. et al., 2003 |
| CTGAATCTCTCGTTTGTTC | GTTCCAGGTGAGTCTCTCTA | Opisthorchis viverrini | WONGRATANACHEEWIN S. et al., 2001 |
| GATCTCACCTATCAGACGAAAC | TCACAACGATACGATACGACCAAC | Schistosoma haematobium | HAMBURGER J. et al., 2001 |
| GAAAATCGTTGTATCTCCG | GGTGACCTGCCTAAAAATAC | Schistosoma mansoni | HAMBURGER J. et al., 1998 |
| GTGACTTGCTACAGGTTGG | GAATGGTATACGAGCTTGCC | Trichobilharzia spp. | HERTEL J. et al., 2002 |
| GACGACAATAGTTGGGGTG | GAATGGTATACGAGCTTGCC | Trichobilharzia spp. | HERTEL J. et al., 2002 |
On the job: Wilfried Haas, Jan Hertel.