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: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.