CA88 is the first long nuclear repetitive DNA sequence identified in the blood fluke,
Schistosoma mansoni
. The
assembled
S. mansoni sequence, which contains the CA88 repeat, has 8,887 nucleotides and at least three repeat units
of approximately 360 bp. In addition, CA88 also possesses an internal CA microsatellite, identified as SmBr18. Both
PCR and BLAST analysis have been used to analyse and confirm the CA88 sequence in other
S. mansoni sequences in
the public database. PCR-acquired nuclear repetitive DNA sequence profiles from nine
Schistosoma species were used
to classify this organism into four genotypes. Included among the nine species analysed were five sequences of both
African and Asian lineages that are known to infect humans. Within these genotypes, three of them refer to recognised
species groups. A panel of four microsatellite loci, including SmBr18 and three previously published loci, has been used
to characterise the nine
Schistosoma species. Each species has been identified and classified based on its CA88 DNA
fingerprint profile. Furthermore, microsatellite sequences and intra-specific variation have also been observed within
the nine Schistosoma species sequences. Taken together, these results support the use of these markers in studying
the population dynamics of
Schistosoma isolates from endemic areas and also provide new methods for investigating
the relationships between different populations of parasites. In addition, these data also indicate that
Schistosoma magrebowiei
is not a sister taxon to
Schistosoma mattheei
, prompting a new designation to a basal clade.
