Intestinal coccidiosis is a common parasitic disease in livestock, caused by the infection of Eimeria and Cystoisospora parasites, which results in great economic losses to animal husbandry. Triazine compounds, such as toltrazuril and diclazuril, are widely used in the treatment and chemoprophylaxis of coccidiosis. Unfortunately, widespread drug resistance has compromised their effectiveness. Most studies have focused on prophylaxis and therapeutics with toltrazuril in flocks, while a comprehensive understanding of how toltrazuril treatment alters the transcriptome of E. tenella remains unknown. In this study, merozoites of E. tenella were treated in vitro with 0.5 μg/mL toltrazuril for 0, 1, 2 and 4 h, respectively. The gene transcription profiles were then compared by high-throughput sequencing. Our results showed that protein hydrolysis genes were significantly upregulated after drug treatment, while cell cycle-related genes were significantly downregulated, suggesting that toltrazuril may affect parasite division. The expression of redox-related genes was upregulated and elevated levels of ROS and autophagosomes were detected in the parasite after toltrazuril treatment, suggesting that toltrazuril may cause oxidative stress to parasite cells and lead to its autophagy. Our results provide basic knowledge of the response of Eimeria genes to toltrazuril and further analysis of the identified transcriptional changes can provide useful information for a better understanding of the mechanism of action of toltrazuril against Eimeria.

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Crystalline optical cavities operating at cryogenic temperatures provide a promising route for realizing the next generation of ultrastable lasers with extremely low thermal noise floor. However, it remains challenging to realize a closed-cycle cryostat for cooling a relatively long cavity to very low temperatures. Here we report on the design and experimental realization of a cryostat operating continuously at 3.1 K for an ultrastable 10-cm silicon cavity. Based on a combination of active temperature control and passive thermal damping, we realize at 3.1 K a two-second temperature instability of 6 × 10−8 K for the cavity. By implementing separate supporting structures for the cryocooler and the sample chamber, we realize vibration control on the 1 × 10−7g level at one second in each spatial direction, where g is the gravitational acceleration. With all these features, our cryostat can support an ultrastable silicon cavity with instability near its fundamental thermal noise floor at averaging time of 1–50 s. With proper upgrading, our platform holds promise for realizing ultrastable lasers with 3 × 10−17 or better frequency stability, which will in turn enable numerous studies on precision metrology and quantum many-body physics.