INVESTIGADORES
CAMPO Vanina Andrea
congresos y reuniones científicas
Título:
Differential accumulation of mutations in pparticular domains of mucin genes expressed in the trypomastigote stage of Trypanosoma cruzi.
Autor/es:
VANINA A. CAMPO; JAVIER M DI NOIA; CARLOS A. BUSCAGLIA; FERNÁN AGÜERO; DANIEL O. SÁNCHEZ; ALBERTO C. C. FRASCH
Lugar:
Bariloche, Rio Negro, Argentina
Reunión:
Congreso; XXXIX Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2003
Institución organizadora:
Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular
Resumen:
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}p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: Helvetica; }table.MsoNormalTable { font-size: 10pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }The surface of Trypanosoma
cruzi is covered by mucin-type
glycoproteins involved in parasite protection, attachment and immunoevasion.
The gene family coding for the mucins expressed by the parasite in the vertebrate
host, named TcMUC, is composed of several hundred members and presents high
variability. The genes encoding mucins expressed in the insect-dwelling
parasite stages are part of a much more homogeneous family, named TcSMUG. Here,
we addressed the organization and evolution of physically linked T. cruzi mucin genes by sequencing large chromosomal fragments
containing these genes. Specific accumulation of mutations was restricted to
particular domains of TcMUC genes, showing that these regions have, or have
had, an accelerated evolution rate. Sequence analysis of several TcMUC genes
allowed for the identification of members sharing features of TcMUC I and II,
thus evidencing that one group of genes was generated from the other. The
highly conserved intergenic regions of both TcMUC and TcSMUG families contained
TG-rich microsatellites that were not present in unrelated genes in the
cosmids, suggesting a role for homologous recombination in shuffling and/or
amplification of T. cruzi mucin
genes. The comparison of putative homologous TcMUC II genes from different
strains of T. cruzi showed that
their central variable domains are conserved. This conservation was always
higher at the DNA level suggesting positive selection in these particular
regions of TcMUC II genes.