Comparative gene expression profiling of Neospora caninum strains

Authors: Li, Robert; Tuo, Wenbin

Submitted to: Experimental Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2009
Publication Date: 1/10/2010
Citation: Li, R.W., Tuo, W. 2010. Comparative gene expression profiling of Neospora caninum strains. Experimental Parasitology. 129:346-354.

Interpretive Summary: To understand the genetic basis of virulence, gene expression profiles of a temperature-sensitive strain (NCts-8) and its wild type (NC-1) of Neospora caninum were characterized and compared using a high-density microarray with approximately 63,000 distinct oligonucleotides. Each sequence is represented by 11 distinct 60mer oligonucleotides synthesized in situ on the microarray. The results of this study showed that 64 genes were significantly down-regulated in the NCts-8 strain when compared to the wild type strain. No up-regulated genes were identified in the NCts-8 strain. Ten randomly selected representative genes from the repressed genes were confirmed using real-time RT-PCR. The repressed genes in NCts-8 included 34 unknown genes, 11 genes coding for hypothetical proteins, 2 genes encoding the dynein light chains, 1 gene coding for a kinase, 1 gene encoding a characterized Neospora membrane protein, 4 genes possibly involved in the metabolic processes, 4 genes coding for proteins with functions in nucleic metabolism, 3 genes are associated with intracellular organelles, 2 genes coding for proteins that may function as transporter proteins, and 2 genes belonging to the ubiquitin family. These results suggest that the down-regulated genes may be in part responsible for the reduced pathogenesis of NCts-8 and further characterization of these genes may aid in understanding of molecular basis of virulence and development of countermeasures against neosporosis.

Technical Abstract: To understand the genetic basis of virulence, gene expression profiles of a temperature-sensitive strain (NCts-8) and its wild type (NC-1) of Neospora caninum were characterized and compared using a high-density microarray with approximately 63,000 distinct oligonucleotides. Each sequence is represented by 11 distinct 60mer oligonucleotides synthesized in situ on the microarray. The results of this study showed that 64 genes were significantly down-regulated in the NCts-8 strain when compared to the wild type strain. No up-regulated genes were identified in the NCts-8 strain. Ten randomly selected representative genes from the repressed genes were confirmed using real-time RT-PCR. The repressed genes in NCts-8 included 34 unknown genes, 11 genes coding for hypothetical proteins, 2 genes encoding the dynein light chains, 1 gene coding for a kinase, 1 gene encoding a characterized Neospora membrane protein, 4 genes possibly involved in the metabolic processes, 4 genes coding for proteins with functions in nucleic metabolism, 3 genes are associated with intracellular organelles, 2 genes coding for proteins that may function as transporter proteins, and 2 genes belonging to the ubiquitin family. These results suggest that the down-regulated genes may be in part responsible for the reduced pathogenesis of NCts-8 and further characterization of these genes may aid in understanding of molecular basis of virulence and development of countermeasures against neosporosis.