ISSN:
1550-7408
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
SYNOPSIS. The total content of DNA in Eimeria tenella, estimated at 5.8 × 10−12 gm/oocyst, varies little during sporulation. Its buoyant density is 1.682 gm/cm3, reflecting a G + C content of ∼41%. Thymidine is not incorporated into any TCA insoluble fraction of sporulating oocysts, but radioactivity from [3H]uridine and [3H]deoxyuridine are incorporated into RNA at a linear rate during the first 5 hr of sporulation. The labeled RNA, found mainly in the paranuclear bodies of newly formed sporozoites, contains ∼0.15 nmole [3H]uridine/106 oocysts at the completion of sporulation. One nmole of leucine is incorporated into the hot TCA insoluble fraction of 106 oocysts during the first 7 hr of sporulation after an initial lag. The incorporated amino acid is mainly in the cytoplasm of the sporozoites, and an analysis by SDS-gel electrophoresis reveals most of the radioactivity in a narrow band with a molecular weight of ∼50,000 daltons. Incorporation of uridine and leucine, however, can be totally suppressed by respiratory inhibition. Further analysis of the proteins in the oocysts reveals that the total protein content remains relatively unchanged at 2.64 × 10−16 gm/oocyst during sporulation, but there is a shift of 13–14% of total protein from the soluble cytoplasm to the 15,000 g pellets. By polyacrylamide gel electrophoresis, a major protein band. possibly a glycoprotein, is shown in the soluble cytoplasm of unsporulated oocysts. This band disappears during sporulation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1550-7408.1975.tb05202.x
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