Apicomplexans are a group of parasitic protozoans, including Plasmodium and Cryptosporidium species, which harbor a specialized organelle called an apicoplast. Of the 145-apicomplexan lineage-specific proteins identified in Cryptosporidium parvum, 30 are surface proteins. In Plasmodium falciparum, a heteromeric complex of three related apicomplexan lineage-specific membrane proteins containing 6 transmembrane domains (m6t) have been identified. These proteins are Pfm6t α, Pfm6t β, and Pfm6t γ and these proteins are localized on merozoite as an inner membrane complex (Rayavara et al. in Mol Biochem Parasitol 167(2):135–143, 2009). In C. parvum, homologs of these proteins are identified and are Cpm6t α, Cpm6t β, and Cpm6t γ. Mass spectrometric analysis of C. parvum (Iowa II) protein extracts of oocyst, sporozoite and soluble and insoluble fractions of cytoplasm identified the presence of Cpm6t α, Cpm6t β, and Cpm6t γ specific peptides in these fractions. The expression of Cpm6t α, Cpm6t β, and Cpm6t γ proteins on various developmental stages of C. parvum suggests that this novel group of apicomplexan lineage-specific proteins in Cryptosporidium may be involved in multiple cellular processes apart from the invasion into host epithelial cells as suggested for P. falciparum merozoites onto host erythrocytes.

Micro and nanoplastics, pervasive environmental pollutants, pose significant threats to ecosystems and human health, necessitating urgent research and innovative solutions. Several research groups have investigated the uptake of synthetic microplastics (MPs) and nanoplastics (NPs) using various model organisms. We investigated the uptake and the growth inhibitory effect of polystyrene (PS) and polymethacrylate (PMA)-based MPs and NPs in Tetrahymena pyriformis. Carboxyl-modified PS-MPs showed a greater growth inhibitory effect than amine-modified PS-MPs and PMA-based MPs. We also studied the impact of these particles on the transcriptomics of T. pyriformis and observed that PS-MPs directly impact various signaling pathways related to oxidative stress. PMA-based MPs showed differential expressions of signaling pathways related to cancer and some related to oxidative stress. Using a fluorescent probe, we measured the reactive oxygen species (ROS) generated by carboxyl-modified PS-MPs and PMA-MPs and observed that PS-MPs generated greater ROS than PMA-MPs. This study suggests that it is important to understand the type and the nature of chemical modification of various MPs and the specific signaling pathways in particular oxidative-related pathways they target on diverse groups of organisms, as this will provide key information related to the effect of various modified MPs and NPs on human health.