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Susceptibility to experimental infection of the invertebrate locusts (Schistocerca gregaria) with the apicomplexan parasite Neospora caninum.

Alkurashi MM, May ST, Kong K, Bacardit J, Haig D, Elsheikha HM - PeerJ (2014)

Bottom Line: Also, N. caninum showed neuropathogenic affinity, induced histological changes in the brain and was able to replicate in the brain of infected locusts.Locusts may facilitate preclinical testing of interventional strategies to inhibit the growth of N. caninum tachyzoites.Further studies on how N. caninum brings about changes in locust brain tissue are now warranted.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Veterinary Medicine and Science, University of Nottingham , Sutton Bonington Campus, Leicestershire , UK ; Animal Production Department, College of Food and Agricultural Sciences, King Saud University , Riyadh , Saudi Arabia.

ABSTRACT
Neuropathogenesis is a feature of Neospora caninum infection. In order to explore this in the absence of acquired host immunity to the parasite, we have tested infection in locusts (Schistocerca gregaria). We show for the first time that locusts are permissive to intra-hemocoel infection with N. caninum tachyzoites. This was characterized by alteration in body weight, fecal output, hemoparasitemia, and sickness-related behavior. Infected locusts exhibited progressive signs of sickness leading to mortality. Also, N. caninum showed neuropathogenic affinity, induced histological changes in the brain and was able to replicate in the brain of infected locusts. Fatty acid (FA) profiling analysis of the brains by gas chromatography and multi-variate prediction models discriminated with high accuracy (98%) between the FA profiles of the infected and control locusts. DNA microarray gene expression profiling distinguished infected from control S. gregaria brain tissues on the basis of distinct differentially-expressed genes. These data indicate that locusts are permissible to infection with N. caninum and that the parasite retains its tropism for neural tissues in the invertebrate host. Locusts may facilitate preclinical testing of interventional strategies to inhibit the growth of N. caninum tachyzoites. Further studies on how N. caninum brings about changes in locust brain tissue are now warranted.

No MeSH data available.


Related in: MedlinePlus

Volcano plot representation of the microarray data showing both significantly expressed transcripts and magnitude of change.Negative log10 p-value on y axis indicates the significance of each gene, and the fold change (log base 2) mean expression difference on the x axis. Each gene is represented by a dot. Data are representative of three hybridizations per group.
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fig-9: Volcano plot representation of the microarray data showing both significantly expressed transcripts and magnitude of change.Negative log10 p-value on y axis indicates the significance of each gene, and the fold change (log base 2) mean expression difference on the x axis. Each gene is represented by a dot. Data are representative of three hybridizations per group.

Mentions: To obtain a broader understanding of the effects of the N. caninum on S. gregaria, we examined the parasite impact on host gene expression using Affymetrix DNA microarray and Cross Species Hybridisation (CSH) analysis. Since N. caninum infection induced neurological injuries in locusts, it was important to test whether N. caninum infection had altered gene expression within locust brains. The analysis was designed to gain further understanding of the mechanisms for N. caninum neuropathy, and in particular, of the genes responsible for the capacity of N. caninum to establish brain infection. We used an established (Lai, May & Mayes, 2014) cross species hybridisation (CSH) approach, which applied genomic DNA pre-filtration to identify conserved probes operationally useful between phylogenetically disparate species; in this case allowing us to use Drosophila Gene Chips to assay locust RNA. Samples of RNA from brains of mock- and N. caninum-infected locusts were labeled and hybridised to Affymetrix Gene Chip Drosophila Genome 2.0 Arrays. Data were analyzed using Partek Genomics Suite Version 6.5. Of the 28,593 transcripts represented on the GeneChip, approximately 18,500 were expressed in the N. caninum-infected locust’s brain. PCA quality control analysis shows that the uninfected and infected samples were biologically noisy but generally well separated (Fig. S5). The subsequent analysis of differential expression was constrained by ≥1.5-fold difference in expression where Fig. 9 shows a graphical representation (volcano plot) of the differential analysis suggesting that our cutoff is somewhat conservative and indicates several significantly differential genes with low fold-change that are not discussed further in this report. It is clear that there are substantial differences in gene expression between infected and control samples. Our chosen fold-change boundaries indicated that 17 transcripts changed significantly (P < 0.05 with FDR filtering) between the uninfected and N. caninum-infected locusts. Of these transcripts, 10 increased >1.5-fold and 6 decreased >−1.5-fold (Table 1). Of the up-regulated transcripts to which a function could be assigned, one transcript was associated with signal transduction and autophagy. Other functional categories that included down-regulated transcripts were developmental processes and metabolism. The identification of these DE transcripts could provide a pipeline for promising targets to test subsequently in mice.


Susceptibility to experimental infection of the invertebrate locusts (Schistocerca gregaria) with the apicomplexan parasite Neospora caninum.

Alkurashi MM, May ST, Kong K, Bacardit J, Haig D, Elsheikha HM - PeerJ (2014)

Volcano plot representation of the microarray data showing both significantly expressed transcripts and magnitude of change.Negative log10 p-value on y axis indicates the significance of each gene, and the fold change (log base 2) mean expression difference on the x axis. Each gene is represented by a dot. Data are representative of three hybridizations per group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4260130&req=5

fig-9: Volcano plot representation of the microarray data showing both significantly expressed transcripts and magnitude of change.Negative log10 p-value on y axis indicates the significance of each gene, and the fold change (log base 2) mean expression difference on the x axis. Each gene is represented by a dot. Data are representative of three hybridizations per group.
Mentions: To obtain a broader understanding of the effects of the N. caninum on S. gregaria, we examined the parasite impact on host gene expression using Affymetrix DNA microarray and Cross Species Hybridisation (CSH) analysis. Since N. caninum infection induced neurological injuries in locusts, it was important to test whether N. caninum infection had altered gene expression within locust brains. The analysis was designed to gain further understanding of the mechanisms for N. caninum neuropathy, and in particular, of the genes responsible for the capacity of N. caninum to establish brain infection. We used an established (Lai, May & Mayes, 2014) cross species hybridisation (CSH) approach, which applied genomic DNA pre-filtration to identify conserved probes operationally useful between phylogenetically disparate species; in this case allowing us to use Drosophila Gene Chips to assay locust RNA. Samples of RNA from brains of mock- and N. caninum-infected locusts were labeled and hybridised to Affymetrix Gene Chip Drosophila Genome 2.0 Arrays. Data were analyzed using Partek Genomics Suite Version 6.5. Of the 28,593 transcripts represented on the GeneChip, approximately 18,500 were expressed in the N. caninum-infected locust’s brain. PCA quality control analysis shows that the uninfected and infected samples were biologically noisy but generally well separated (Fig. S5). The subsequent analysis of differential expression was constrained by ≥1.5-fold difference in expression where Fig. 9 shows a graphical representation (volcano plot) of the differential analysis suggesting that our cutoff is somewhat conservative and indicates several significantly differential genes with low fold-change that are not discussed further in this report. It is clear that there are substantial differences in gene expression between infected and control samples. Our chosen fold-change boundaries indicated that 17 transcripts changed significantly (P < 0.05 with FDR filtering) between the uninfected and N. caninum-infected locusts. Of these transcripts, 10 increased >1.5-fold and 6 decreased >−1.5-fold (Table 1). Of the up-regulated transcripts to which a function could be assigned, one transcript was associated with signal transduction and autophagy. Other functional categories that included down-regulated transcripts were developmental processes and metabolism. The identification of these DE transcripts could provide a pipeline for promising targets to test subsequently in mice.

Bottom Line: Also, N. caninum showed neuropathogenic affinity, induced histological changes in the brain and was able to replicate in the brain of infected locusts.Locusts may facilitate preclinical testing of interventional strategies to inhibit the growth of N. caninum tachyzoites.Further studies on how N. caninum brings about changes in locust brain tissue are now warranted.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Veterinary Medicine and Science, University of Nottingham , Sutton Bonington Campus, Leicestershire , UK ; Animal Production Department, College of Food and Agricultural Sciences, King Saud University , Riyadh , Saudi Arabia.

ABSTRACT
Neuropathogenesis is a feature of Neospora caninum infection. In order to explore this in the absence of acquired host immunity to the parasite, we have tested infection in locusts (Schistocerca gregaria). We show for the first time that locusts are permissive to intra-hemocoel infection with N. caninum tachyzoites. This was characterized by alteration in body weight, fecal output, hemoparasitemia, and sickness-related behavior. Infected locusts exhibited progressive signs of sickness leading to mortality. Also, N. caninum showed neuropathogenic affinity, induced histological changes in the brain and was able to replicate in the brain of infected locusts. Fatty acid (FA) profiling analysis of the brains by gas chromatography and multi-variate prediction models discriminated with high accuracy (98%) between the FA profiles of the infected and control locusts. DNA microarray gene expression profiling distinguished infected from control S. gregaria brain tissues on the basis of distinct differentially-expressed genes. These data indicate that locusts are permissible to infection with N. caninum and that the parasite retains its tropism for neural tissues in the invertebrate host. Locusts may facilitate preclinical testing of interventional strategies to inhibit the growth of N. caninum tachyzoites. Further studies on how N. caninum brings about changes in locust brain tissue are now warranted.

No MeSH data available.


Related in: MedlinePlus