Project description:Intraspecific phenotypic variation markedly influences the damage that parasites inflict on their hosts. Such is the case for strains of Eimeria maxima, a costly enteric parasite of poultry, where strain APU-1 exhibits greater pathogenicity than APU-2. Here, we examined how these strains differ as oocysts mature to the fully-sporulated stage. We performed mi-croscopy and RNA-Sequencing on oocysts at regular intervals (6-12 hours) during sporulation. Although each strain underwent parallel development, APU-1 initially approached maturation more slowly. Each strain achieved full sporu-lation and similar transcription profiles by hour 36, after which strains appeared to diverge. These differences may in-fluence subsequent virulence. Candidate biomarkers of oocyst viability include 58 genes contributing at least 1,000 Transcripts Per Million throughout sporulation. Many genes resemble constitutively expressed genes also important to Eimeria acervulina. Mature and immature oocysts differentially express certain genes. Expression of some such bi-omarkers appears strain-specific. These data illuminate processes that may generally underlie sporulation in Eimeria and related genera, such as Cyclospora, and identify biological processes which differentiate among them. Drivers of devel-opment and senescence may provide tools to assess the viability of oocysts, which would greatly benefit the poultry industry and food safety applications.
Project description:Avian coccidiosis is a major disease of poultry caused by the intestinal protozoa Eimeria. Aviagen line A and line B birds show differential susceptibility to Eimeria infection, with line B birds exhibiting higher lesion scores and mortality. The objective of this study was to examine differential intestinal gene expression between line A and B chicks in response to a challenge with Eimeria maxima. Following challenge with 1 x 10^4 oocysts/chick, greater than 40% of line A chicks had lesion scores of 0 to 1 (on 0 to 4 scale), similar to controls. In contrast, all line B challenged chicks at this same dose had lesion scores of 2 to 4.
Project description:Avian coccidiosis is a major disease of poultry caused by the intestinal protozoa Eimeria. Aviagen line A and line B birds show differential susceptibility to Eimeria infection, with line B birds exhibiting higher lesion scores and mortality. The objective of this study was to examine differential intestinal gene expression between line A and B chicks in response to a challenge with Eimeria maxima. Following challenge with 1 x 10^4 oocysts/chick, greater than 40% of line A chicks had lesion scores of 0 to 1 (on 0 to 4 scale), similar to controls. In contrast, all line B challenged chicks at this same dose had lesion scores of 2 to 4. Total RNA was extracted from the jejunum of control and challenged chicks from both lines A and B. Microarrays were used for detecting the expression-changed genes which responsed to the Eimeria challenge. Samples included: four control A chicks, two challenged A chicks with a lesion score of 1 (A/LS1), two challenged A chicks with lesion scores of 3 to 4 (A/LS3-4), four control B chicks, two challenged B chicks with lesion scores of 2 (B/LS2-3) and two challenged B chicks with lesion scores of 4 (B/LS4). The DNA microarrays were processed at the Virginia Bioinformatics Institute (Virginia Tech) core facility. The raw array data were normalized using GC-robust multiple array (GC-RMA) normalization. Analysis of variance was used for differentially expressed genes based on Welch ANOVA (P < 0.05) and probe set lists were ordered using the fold change analysis provided by GeneSpring software.
Project description:Eimeria (E.) maxima parasite infects the midgut disrupting the jejunal and ileal mucosal lining causing high morbidity and mortality in chickens. Heat stress (HS) is a seasonal stressor that affects biological functions leading to poor performance. Our objective was to elucidate how HS, E. maxima infection, and their combination affect the ileum transcriptome. Two-hundred and forty 2-week-old males Ross708 chickens were randomly allocated into four treatment groups: thermoneutral control (TNc), thermoneutral infected (TNi), heat stress control (HSc), and heat stress infected (HSi), with 6 replicates each of 10 birds. Infected groups received 200x103 sporulated E. maxima oocysts/bird, and heat treatment groups were raised at 35oC. At 6-day post-treatment, five chickens per group were randomly sampled, and ileum tissues were collected for RNA extraction and sequencing using NGS Illumina sequencing platforms. A total of 413, 3377, 1908, and 2304 DEGs were identified when applying the comparisons: TNc vs HSc, TNc vs TNi, HSi vs HSc, and TNi vs HSi, respectively, at cutoff ≥1.2-fold change (FDR: q<0.05). HSc vs TNc showed upregulation of lipid metabolic pathways and degradation and metabolism of multiple amino acids, and downregulation of most immune-related and protein synthesis pathways. TNc vs TNi displayed upregulation of most of the immune-associated pathways and eukaryotic mRNA maturation pathways, and downregulation of fatty acid metabolism and multiple amino acid metabolism pathways including tryptophan. Comparing HSi versus HSc and TNi revealed that combining the two stressors restored some normal cellular functions, e.g., oxidative phosphorylation and protein synthesis, and reduced the intensity of immune response associated with E. maxima infection. Tryptophan metabolism was upregulated, including genes that contribute to catabolizing tryptophan through serotonin and indole pathways; which might result in reducing the cytoplasmic pool of nutrients and calcium available for the parasite to scavenge and consequently might affect the parasite’s reproductive ability.
Project description:Eimeria are obligate intracellular protozoan parasites which can affect chickens. After exposure to Eimeria chickens establish (partial) protective immunity to the homologues strain. In this paper we investigate the process responsible for Eimeria protection. In order to find host reactions specificly involved in protection to homologous re-infection we investigated the host reactions after primary infection and a homologous or heterologous secondary infection.<br><br>Broilers were mock infected or infected with E.maxima (Max) at one week of age. Two weeks later broilers were mock infected, infected with E.maxima or E.acervulina. Oocyst output, T-cell population and cytokine mRNA expression profiles and Eimeria DNA profiles were measured 2, 4 and 7 days pi. Specific regulation of gene expression profiles was monitored by a whole genome oligo-array containing 20.673 oligoï¾´s at 8 and 24 hours pi.<br><br>