Títol:
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Deciphering the principles that govern mutually exclusive
expression of Plasmodium falciparum clag3 genes
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Autor/a:
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Rovira Graells, Núria; Crowley, Valerie M.; Bancells, Cristina; Mira-Martinez, Sofia; Ribas de Pouplana, Lluís; Cortés, Alfred
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Abstract:
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The product of the Plasmodium falciparum genes clag3.1 and
clag3.2 plays a fundamental role in malaria parasite biology by
determining solute transport into infected erythrocytes.
Expression of the two clag3 genes is mutually exclusive, such
that a single parasite expresses only one of the two genes at a
time. Here we investigated the properties and mechanisms of
clag3 mutual exclusion using transgenic parasite lines with
extra copies of clag3 promoters located either in stable
episomes or integrated in the parasite genome. We found that the
additional clag3 promoters in these transgenic lines are
silenced by default, but under strong selective pressure
parasites with more than one clag3 promoter simultaneously
active are observed, demonstrating that clag3 mutual exclusion
is strongly favored but it is not strict. We show that silencing
of clag3 genes is associated with the repressive histone mark
H3K9me3 even in parasites with unusual clag3 expression
patterns, and we provide direct evidence for heterochromatin
spreading in P. falciparum. We also found that expression of a
neighbor ncRNA correlates with clag3.1 expression. Altogether,
our results reveal a scenario where fitness costs and
non-deterministic molecular processes that favor mutual
exclusion shape the expression patterns of this important gene
family. |
Matèries:
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-Plasmodium falciparum -Malària -Plasmodium falciparum -Malaria |
Drets:
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cc by (c) Rovira-Graells et al., 2015
http://creativecommons.org/licenses/by/3.0/es/ |
Tipus de document:
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Article Article - Versió publicada |
Publicat per:
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Oxford University Press
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Compartir:
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