Related Experiment Video
Updated: Oct 2, 2026
Understanding the Development of Compensatory Pathways in a Mutant Malaria Parasite Harbouring Hypomorphic Allele of Plant-Like Kinases
Published on: November 22, 2024
Expression of the highly polymorphic Cryptosporidium parvum Cpgp40/15 gene in genotype I and II isolates
Roberta M O'Connor1, Cheleste M Thorpe, Ana-Maria Cevallos
1Division of Geographic Medicine and Infectious Diseases, New England Medical Center, Tufts University School of Medicine, Box 041, 750 Washington Street, Boston, MA 02111, USA. roconnor@lifespan.org
Abstract:
The enteric protozoan Cryptosporidium parvum infects intestinal epithelial cells in a wide range of hosts, causing severe gastrointestinal disease. The invasive sporozoite stage most likely attaches to and invades host cells through multiple host receptor/parasite ligand interactions. Preliminary evidence suggests that the glycoprotein products of the Cpgp40/15 gene, gp40 and gp15, are involved in these interactions. In addition, the Cpgp40/15 gene that encodes these glycopeptides is highly polymorphic in genotype I isolates, suggesting that the gene products may be subject to immune selection. In this study, we characterized the Cpgp40/15 gene in a genotype I isolate and compared expression of the Cpgp40/15 gene in isolates of both genotype. Cpgp40/15 is a single copy gene in both TU502 (genotype I) and GCH1 (genotype II) isolates. However, Northern blot analysis revealed the presence of two transcripts, 2.3 and 1.5 kb in size, in mRNA from GCH1 as well as TU502-infected Caco-2A cells. Accumulation of the two Cpgp40/15 mRNAs peaked 12-24 h post-infection. Using 3'RACE analysis, three polyadenylation sites were identified 371, 978 and 1002 bp downstream of the GCH1 Cpgp40/15 stop codon. Two of these polyadenylation sites were also used in TU502. The sequences of the GCH1 Cpgp40/15 3'untranslated regions (3'UTRs) were identical to genomic sequence and shared 96.7% homology with TU502 3'UTRs. Actinomycin D treatment of GCH1-infected Caco-2A cells followed by Northern blot analysis, revealed that the stability of the 1.5 kb message was considerably greater than that of the 2.3 kb transcript.
Insights
Cryptosporidium parvum uses the Cpgp40/15 gene to infect host cells. This study found two Cpgp40/15 gene transcripts with different stabilities, potentially impacting parasite invasion.
Area of Science:
- Parasitology
- Molecular Biology
- Host-Pathogen Interactions
Background:
- Cryptosporidium parvum causes gastrointestinal disease by infecting intestinal epithelial cells.
- The Cpgp40/15 gene products (gp40, gp15) are implicated in host cell attachment and invasion.
- The Cpgp40/15 gene is polymorphic, suggesting immune selection pressure.
Purpose of the Study:
- To characterize the Cpgp40/15 gene in a genotype I isolate.
- To compare Cpgp40/15 gene expression in different Cryptosporidium parvum genotypes.
- To investigate the molecular basis of Cpgp40/15 gene expression.
Main Methods:
- Northern blot analysis to detect Cpgp40/15 gene transcripts.
- 3'RACE analysis to identify polyadenylation sites.
- Actinomycin D treatment to assess mRNA stability.
Main Results:
- Cpgp40/15 is a single-copy gene in both genotype I and II isolates.
- Two transcripts (2.3 kb and 1.5 kb) of Cpgp40/15 were detected, peaking 12-24 hours post-infection.
- Three polyadenylation sites were identified, with two shared between genotypes; the 1.5 kb transcript exhibited greater stability.
Conclusions:
- The Cpgp40/15 gene produces distinct transcripts with differential stability.
- Understanding Cpgp40/15 gene expression and regulation is crucial for deciphering Cryptosporidium parvum invasion mechanisms.
- Variations in Cpgp40/15 gene expression may contribute to host-parasite interactions and immune evasion.
