Isolation and characterization of a subtractive library enriched for developmentally regulated transcripts expressed during encystation of Toxoplasmagondii
B. Yahiaoui et al., Isolation and characterization of a subtractive library enriched for developmentally regulated transcripts expressed during encystation of Toxoplasmagondii, MOL BIOCH P, 99(2), 1999, pp. 223-235
To survive within infected hosts, Toxoplasma gondii undergoes profound meta
bolic and morphological changes by differentiating into a cyst characterize
d by its resistance to the immune system and chemotherapy. The stimulus tha
t triggers Toxoplasma encystation and the molecular mechanisms regulating t
he bradyzoite phenotype are still unknown. Here, we developed a differentia
tion method in conjunction with a selective and subtracted cDNA strategy de
vised to identify developmentally regulated transcripts. We isolated and an
alyzed 65 cDNA clones. In addition to bradyzoite specific cDNAs previously
reported, we demonstrate that twelve genes are exclusively or preferentiall
y transcribed in the encysted bradyzoite forms of T. gondii using semi-quan
titative RT-PCR. Among cDNAs identified, are those encoding predicted homol
ogues of chaperones (mitochondrial heat shock protein 60, T-complex protein
1), DNA-damage repair protein, phosphatidylinositol synthase, glucose-6-ph
osphate isomerase and enolase. The identification of these genes opens the
way for further study of molecular mechanisms controlling gene expression d
uring T. gondii encystation. (C) 1999 Elsevier Science B.V. All rights rese
rved.