Comparative Genomic and Transcriptomic Profiling Revealed the Molecular Basis of Starch Promoting the Growth and Proliferation of Balantioides coli .

Carbohydrates are the main source of nutrition for , supplying energy for cell growth and development. The research aimed at investigating the mechanism of starch on the growth and replication of . Single-cell separation was used to isolate single trophozoites of under a stereomicroscope, transcriptomic profiling was conducted based on the SMART-seq2 single-cell RNA-seq method. Comparative genomic analysis was performed on and eight other ciliates to obtain specific and expanded gene families of . GO and KEGG enrichment analysis were used to analyze the key genes of under the action of starch in the present study. The results of single-cell RNA-seq depicts starch affected the growth and replication of in two ways: (1) the cell cycle was positively promoted by the activation of the cAMP/PKA signaling pathway via glycolysis; (2) the cell autophagy was suppressed through the PI3K/AKT/mTOR pathway. Genes involved in endocytosis, carbohydrate utilization, and the cAMP/PKA signaling pathway were highly enriched in both specific and expanded gene families of . Starch can be ingested and hydrolyzed into glucose, in turn affecting various biological processes of . The molecular mechanism of the effect of starch on the growth and proliferation of by promoting cell cycle and inhibiting the autophagy of trophozoites has been elucidated in our study.