Biochemistry of Sporulation in Oocysts of Eimeria acervulina*

Abstract

Oocysts of Eimeria acervulina Tyzzer, 1929 were collected at the time of their first massive discharge into the chick intestine, and isolated in the cold by means of continuous centrifugal flotation in high‐density media. Maximum numbers (90%) of sporoblastic oocysts were obtained by incubating at 30°C for 10 hr and sporulation was considered complete within 20 hr. The initial Qo2 (dry‐weight basis) of 9.5 decreased linearly to < i/3 this value in 20 hr, and more slowly thereafter to very low levels. The QCO2 was higher than Qo2 only during the first 10 hr. A 15% decrease in dry weight in 15 hr was due chiefly to disappearance of alkali‐stable carbohydrate, probably identical with glycogen. In the later stages carbohydrate was resynthesized. Lipids were not oxidized during sporoblast formation, but disappeared rapidly betweem 10 and 30 hr. Total nitrogen remained constant, indirect evidence suggesting that protein was not used to supply oxidative energy The change‐over from carbohydrate to fat metabolism corresponded with observed changes in the respiratory quotient, and also with near‐completion of sporulation. Apparently carbohydrate provided the energy needed for the earlier stages of sporulation, whereas oxidation of lipids supported the teal stages as well as the metabolism during dormancy.

Molecular Characterization and Functional Analysis of a Novel Calcium-Dependent Protein Kinase 4 from Eimeria tenella

“…tenella life cycle. Sporulated oocysts in the environment require material for metabolism from the storage of oocysts [45]. Without an energy supply, sporulated oocysts maintain a low metabolic rate until they can infect fresh host cells [46].…”

Desenvolvimento da plataforma EGene para anotação funcional e integração com banco de dados: aplicação e validação em transcritos de Eimeria spp. de galinha doméstica.

“…The apparent discrepancy in results can be ascribed to some potential variables, including the different parasite strains and/or quality of reagents used across the distinct laboratories. For E. acervulina, Wilson and Fairbairn (1961) observed 90% of the oocysts at the sporoblast phase after 10 h incubation at 30 o C. In our case, using incubation at 28 o C, we observed a final sporulation rate of 85-90%, with a peak of sporoblasts at 13 h. In E. maxima, Pittilo and Ball (1985) reported that within 21-30 h of incubation at 29 o C, the sporoblasts have been transformed into sporocysts containing sporozoites. Our results, using the same strain (H), are in good agreement, since we obtained a final sporulation rate of 75-80%, with a peak of sporoblasts at 23 h.…”

DNA extraction methods for molecular detection of Eimeria spp. in cattle and sheep

“…Eimeria's oocyst walls contain two or more shell layers (Scholtyseck et al 1971, Hammond & Long 1973, Duszynski et al 1981, Long 1982. The thick and elastic outer skeletal layer is made of a chitin-like material (Wilson & Fairbairn 1961) and contains quinone-tanned proteins that can be dissolved in hypochlorite (Hammond & Long 1973). Some DNA extraction protocols use sodium hypochlorite to promote oocysts lysis (Carvalho et al 2011, Tang et al 2018 and although none of the six protocols tested used hypochlorite, they showed to be efficient in oocysts lysis resulting in positive PCRs.…”