Localization of mouse type 2 Alu sequence in schistosomes

Area of Science:

• Parasitology
• Molecular Biology
• Genomics

Background:

• Schistosomes are parasitic flatworms causing significant human disease.
• Understanding host-parasite molecular interactions is crucial for developing control strategies.
• Repetitive DNA elements can offer insights into genome dynamics and host-parasite relationships.

Purpose of the Study:

• To investigate the presence and localization of the mouse type 2 Alu (B2) sequence in different developmental stages and species of schistosomes.
• To determine if host DNA sequences are integrated or accumulated within the parasite during infection.

Main Methods:

• In situ polymerase chain reaction (in situ PCR) was employed to detect the B2 sequence.
• Analysis was performed on Schistosoma japonicum and Schistosoma mansoni at various developmental time points (3-week schistosomula, 8-week, and 24-week adults).

Main Results:

• The B2 sequence was detected in the cytoplasm and nuclei of various schistosome cells in adult S. japonicum and S. mansoni, with notable differences between species and sexes.
• Signal intensity and localization varied with parasite age and sex, suggesting developmental regulation.
• No B2 sequence signals were found in 3-week schistosomula, indicating accumulation occurs post-larval stages.

Conclusions:

• Host DNA sequences, specifically the mouse B2 Alu sequence, are present in schistosome tissues.
• These host DNA sequences accumulate within the parasite during its development, particularly in adult worms.
• The findings suggest a dynamic interaction where host genetic material is acquired by the parasite over time.