ULTRASTRUCTURAL OBSERVATIONS ON MICROGAMETOGENESIS AND THE STRUCTURE OF THE MICROGAMETE OF ISOSPORA FELIS

Abstract

observations on microgametogenesis and the structure of the microgamete of lsosporu ,felis. Acta path. microbiol. scand. Sect. B, 88: 151-159, 1980.The endogenous forms of lsospora felis were observed within the epithelial cells of the small intestine of the cat. They 'were situated within a parasitophorous vacuole which was limited by a multimembranous wall. The ultrastructural features of microgametogenesis were studied at 8 days posiinfection. The initial phase of microgamont development consisted of cytoplasmic growth accompanied by a number of nuclear divisions. The gamont was enclosed by a pellicle and its surface area was greatly increased by deep invaginations. In the later stages of development the numerous nuclei were situated close to the pellicle. Each nucleus has peripherally condensed chromatin. Formation of the microgametes occurred as protrusions from the microgamont surface. Two basal bodies. the dense portion of a nucleus and a mitochondrion entered each protrusion. The microgametes matured while still attached to the gamont from which they finally budded off into the parasitophorous vacuole leaving a large residual cytoplasmic mass. The mature microgamete was found to consist of an elongate nucleus which overlaps with a mitochondrion towards the anterior end of the organism. The anterior portion contains a dense perforatorium and two basal bodies with attached flagella. In addition a number of microtubules (5-9) were found to run longitudinally from the basal body region.

Isospora suis in an Epithelial Cell Culture System – An In Vitro Model for Sexual Development in Coccidia

“…Unlike microgametogenesis described in Isospora felis (syn. Cystoisospora felis ) [38], no deep invaginations of the gamont surface appear in I . suis .…”

MORN1 Has a Conserved Role in Asexual and Sexual Development across the Apicomplexa

“…The formation of a MORN1-positive ring-like structure beneath the plasmalemma is shared between both sexual and asexual development, but in the case of the microgametocyte, MORN1 was associated with amorphous dense material located beneath the plasmalemma in the absence of an IMC. The dense collar at the site of microgamete protrusion has previously been described for various species of Eimeria, Isospora felis, and T. gondii (6,11,33). It appears that MORN1 is associated with ring formation and maintains the integrity of the site of microgamete budding.…”

Parasitic diarrheal disease: drug development and targets

“…The currently used drugs against this infection is combination of trimethoprim ( 82 ) and sulfamethoxazole ( 83 ) (Goodgame, 2003 ; Hunter et al, 2004 ). The pyrimethamine ( 88 ) and sulfadiazine ( 89 ) also cure the diarrheal disease caused by I. Belli (Ferguson et al, 1980 ; Ebrahimzadeh and Bottone, 1996 ). Macrolide antibiotics like sirimamycin proved to be effective when pyrimethamine-sulfadoxine ( 88 , 90 ) fails to cure the intestinal infection by I. belli specifically in AIDS patients (Ferguson et al, 1980 ).…”

“…The pyrimethamine ( 88 ) and sulfadiazine ( 89 ) also cure the diarrheal disease caused by I. Belli (Ferguson et al, 1980 ; Ebrahimzadeh and Bottone, 1996 ). Macrolide antibiotics like sirimamycin proved to be effective when pyrimethamine-sulfadoxine ( 88 , 90 ) fails to cure the intestinal infection by I. belli specifically in AIDS patients (Ferguson et al, 1980 ). Similarly, roxithromycin ( 91 ) is also observed to be effective for chronic I. belli induced diarrhea when TMP-SMX ( 82 , 83 ) or pyrimethamine ( 88 ) treatments become inadequate (Musey et al, 1988 ).…”