Structure and polymorphism of the upstream region of the pfg27/25 gene, transcriptionally regulated in gametocytogenesis of Plasmodium falciparum.
Transcription of the early gametocyte-specific gene pfg27/25, and genomic structure and polymorphism of its upstream region were studied in the human malaria parasite Plasmodium falciparum. The upstream genomic sequence of the pfg27/25 gene is characterised by a repetitive region that contains five direct and one inverted repeats of a unit constituted by a perfectly conserved sequence flanked by a poly-dT and a poly-d(AT) tract. Sequences further upstream from the repetitive region are polymorphic in distantly related parasite lines. Nuclear 'run off' experiments indicated that transcription of pfg27/25 is developmentally regulated. Transcription of the gene, undetectable in asexual parasites, is activated at the onset of gametocytogenesis. Te gene is transcribed in a 2.5 kb mature mRNA for the first 2-3 days of sexual differentiation, while transcription is down-regulated in more mature gametocytes.
Alano
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Laboratorio di Biologia Cellulare, Istituto Superiore di Sanità, Rome, Italy.
Silvestrini
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F
Roca
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D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D005718:Gametogenesis / Q000235:genetics*; D017125:Genes, Protozoan / Q000235:genetics*; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000235:genetics* / Q000254:growth & development; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics*; D014158:Transcription, Genetic
D015800:Protozoan Proteins; C069962:Pfg25-27 protein, Plasmodium falciparum