Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1997 Oct;26(2):289-300.
doi: 10.1046/j.1365-2958.1997.5721933.x.

Virus-like, double-stranded RNAs in the parasitic protozoan Cryptosporidium parvum

N V Khramtsov  1 , K M Woods, M V Nesterenko, C C Dykstra, S J Upton
Affiliations
Free article

Virus-like, double-stranded RNAs in the parasitic protozoan Cryptosporidium parvum

N V Khramtsov et al. Mol Microbiol. 1997 Oct.
Free article

Abstract

We have discovered and analysed two novel, linear extrachromosomal double-stranded RNAs (dsRNAs) within oocysts of major north Amercian isolates of Cryptosporidium parvum, a parasitic protozoan that infects the gastrointestinal tract of a variety of mammals, including humans. These dsRNAs were found to reside within the cytoplasm of sporozoites, and were not detected in other species of the genus. cDNAs representing both dsRNA genomes were cloned and sequenced, 1786 and 1374 nt, and each encoded one large open reading frame (ORF). The deduced protein sequence of the larger dsRNA (L-dsRNA) had homology with viral RNA-dependent RNA polymerases (RDRP), with more similarity to polymerases from fungi than those from other protozoa. The deduced protein sequence from the smaller dsRNA (S-dsRNA) had limited similarity with mitogen-activated c-June NH2 terminal protein kinases (JNK) from mammalian cells. Attempts to visually identify or purify virus-like particles associated with the dsRNAs were unsuccessful. Sensitivity of the dsRNAs to RNase A also suggests that the dsRNAs may be unencapsidated. A RDRP activity was identified in crude extracts from C. parvum sporozoites and products of RNA polymerase activity derived in vitro were similar to the dsRNAs purified directly from the parasites.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types

Associated data

LinkOut - more resources