INVESTIGADORES
MARCIPAR Ivan Sergio
artículos
Título:
Trypanosoma cruzi: An analysis of the minicircle hypervariable regions diversity and its influence on strain typing
Autor/es:
VELAZQUEZ MELISA; DIEZ CRISTINA; MORA CELESTE; DIOSQUE PATRICIO; MARCIPAR IVAN
Revista:
EXPERIMENTAL PARASITOLOGY
Referencias:
Año: 2008 vol. 120 p. 235 - 241
ISSN:
0014-4894
Resumen:
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The current
intraspecific nomenclature in Trypanosoma cruzi describes two major lineages,
named T. cruzi I and T. cruzi II, and five sub-lineages within T. cruzi II,
named IIa, IIb, IIc, IId and IIe. The polymorphism of minicircle hypervariable
regions (mHVRs) of T. cruzi has been used in many studies for the molecular
characterization of parasite populations directly from biological samples. However,
the molecular bases that allow strain typing by these markers are still
unclear. In this work we examine forty cloned mHVRs sequences of
CL-Brener reference strain (IIe sub-lineage), and we found a predominant group
of sequences, with 40% of frequency in this strain, with a 97% of identity
among them. Out of the forty clones analyzed, we identified other less representative
types, and a few unique ones. This predominant sequence is also present in
different reference strains belonging to the other main T. cruzi lineages and
sub-lineages (TcI, IId, IIa, IIb, IIc and IId) although in a many thousand
times lower frequency than in the CL-Brener strain, as shown by
semiquantitative PCR. Similarly, predominant mHVR sequences previously
described for TcIId strains, were clearly more frequent (many thousand times
higher) in the IId reference strain analyzed by us (Mncl2) than within the
reference strains belonging to the other lineages and sub-lineages. The
analysis of the cloned sequences shows that more sequences than just the major
one contribute to define the global pattern of mHVRs RFLP in the CL-Brener
strain. The possible usefulness of these predominant sequences for typing TcIId
and TcIIe sublineages by semiquantitative PCR, as well as the possible role of
these sequences in genotype identification by mHVR probes are discussed.