Expression of fragmented ribosomal RNA from the mitochondrial genome of Eimeria tenella.

Highly fragmented ribosomal RNA-coding sequences are characteristic of mitogenomes of protozoan parasites of the phylum Apicomplexa. Identification of ribosomal RNA encoding sequences in apicomplexan mitogenomes has largely relied on sequence similarity with several apicomplexan species for which expression of these genes has been demonstrated. The present study applied Next-Gen sequencing to investigate the expression of fragmented putative mitochondrial rRNAs inEimeria tenella, a coccidian parasite of poultry.

Organellar genome dynamics of exogenous stages of Eimeria tenella.

Background: Coccidia are a group of intracellular protozoal parasites within the phylum Apicomplexa. Eimeria tenella, one of the species that cause intestinal coccidiosis in poultry, can cause significant mortality and morbidity. Diploid oocysts of Eimeria species are shed in the feces of an infected host and must sporulate to achieve infectivity.

Prolonged survival out of water is linked to a slow pace of life in a self-fertilizing amphibious fish.

Metabolic rate and life-history traits vary widely both among and within species, reflecting trade-offs in energy allocation, but the proximate and ultimate causes of variation are not well understood. We tested the hypothesis that these trade-offs are mediated by environmental heterogeneity, using isogenic strains of the amphibious fish that vary in the amount of time each can survive out of water. Consistent with pace of life theory, the strain that survived air exposure the longest generally exhibited a 'slow' phenotype, including the lowest metabolic rate, largest scope for metabolic depression, slowest consumption of energy stores and least investment in reproduction under standard conditions.