Schistosoma mansoni is 1 of the causative agents of schistosomiasis,
an endemic disease in 76 countries of the world. The study
of its genome, estimated to be 270 Mb, is very important to understanding
schistosome biology, the mechanisms of drug resistance, and immune
evasion. Repetitive elements constitute more than 40% of the S.
mansoni genome and may play a role in the parasite evolution. The
retrotransposons Boudicca, a long terminal repeat (LTR), and Perere 03,
a non-LTR, are present in a high number in the S. mansoni genome and
were localized with the use of fluorescence in situ hybridization (FISH)
and primed in situ labeling (PRINS). Bacterial artificial chromosomes
(BAC) clones containing the retrotransposons Boudicca and Perere 03
were selected by bioinformatic analysis and used as probes in FISH.
Using metaphase chromosomes from sporocysts and the FISH and
PRINS techniques, we were able to map these retrotransposons. Perere
03 was localized in the euchromatic regions of the short arm of chromosome
2 and Boudicca i