PMC

Competitive band shift analysis with normal and mutated oligonucleotide 5b1. (A) The oligonucleotide 5b1, the mutated oligonucleotide 5b1 (mutated nucleotides are underlined and shown in boldface) and the canonical STRE of S.cerevisiae are shown. (B) Gel shift binding assay with oligonucleotide 5b1 (left-hand side) and the nuclear extract from tachyzoite: lane 1, free 5b1 probe, lane 2, 5b1 probe with tachyzoite nuclear extract and no competitor; lane 3, 5b1 probe with tachyzoite nuclear extract and specific competitor (150-fold excess); and lane 4, 5b1 probe with tachyzoite nuclear extract and specific competition with the mutated oligonucleotide 5b1 (100-fold excess). Lane 5, free mutated 5b1 probe; lane 6, mutated 5b1 probe with tachyzoite nuclear extract and no competitor; and lane 7, mutated 5b1 probe with tachyzoite nuclear extract and specific competition with the mutated oligonucleotide 5b1 (100-fold excess). Note the complete loss of protein binding with the mutated oligonucleotide 5b1. Lane 8, free 5b1 probe; lane 9, 5b1 probe with tachyzoite nuclear extract and no competitor; lane 10, 5b1 probe with tachyzoite nuclear extract and competition with specific competitor (100-fold excess); and lane 11, 5b1 probe with tachyzoite nuclear extract and competition with S.cerevisiae (yeast) STRE (100-fold excess). Lane 12, free yeast STRE probe; lane 13, yeast STRE probe with tachyzoite nuclear extract and no competitor; lane 14, yeast STRE probe with tachyzoite nuclear extract and competition with specific competitor; and lane 15, yeast STRE probe with tachyzoite nuclear extract and competition with oligonucleotide 5b1 (100-fold excess).

SEM of T. gondii tachyzoites collected from the peritoneal cavity of infected mice from different studied subgroups. (a): Tachyzoite from subgroup Ia (infected untreated control), presenting crescent shape with obvious conoid (×10,000). (b): Tachyzoite from subgroup Ib, showing evident ballooning, distortion of the crescent shape with multiple large papules on the surface and loss of the tapered ends. (×10,000). (c): Tachyzoite from subgroup IIa, showing loss in the crescent shape with disorganized lacerated outer surface (×10,000). (d): Tachyzoite from subgroup IIb, showing a shrunken distorted organism losing its crescent shape, tapered ends and conoid with marked surface erosion and ulceration (×10,000). (e): Tachyzoite from subgroup IIc, showing mutilated rapturing organism losing its conoid with disorganized lacerated surface (×10,000). (f): Tachyzoite from subgroup IId, indicating lacerated parasite losing its smooth surface (×10,000). (g): Tachyzoite from subgroup IIe, showing rapturing mutilated organism losing its conoid and smooth surface (×10,000). (h): Tachyzoite from subgroup IIf, showing disfigured rapturing parasite with marked ballooning along with damaged crescent shape and loss of the tapered ends (×10,000).

Transmission electron micrograph of a tachyzoite of the VEG strain of T. gondii undergoing endodyogeny within a mouse peritoneal macrophage to form two daughter tachyzoites. Cd, conoid of developing tachyzoite; Co, conoid of mother tachyzoite; Dg, electron-dense granule; Ga, Golgi adjunct; Hm, host cell mitochondrion; Hn, host cell nucleus; Id, inner membrane complex of developing tachyzoite; Im, inner membrane complex of mother tachyzoite; Mi, microchdrion; Mn, microneme; Nu, nuclei of daughter tachyzoites; Pl, plasmalemma of mother tachyzoite; Pm, parasitophorous vacuolar membrane; Pv, parasitophorous vacuole; Rh, rhoptries of daughter tachyzoites.

Clusters of genes that are tachyzoite specific or bradyzoite specific. Clusters include genes called significant by SAM in either tachyzoite infection or bradyzoite infection that, upon examination (see the text), met the criteria for being “tachyzoite specific” (A and B) or “bradyzoite specific” (C). Color-coding is as described for Fig. . Genes with asterisks are discussed in detail in the text.