Transcriptome of Taenia solium during in vitro cyst activation and initial growth into the tapeworm stage

Abstract

The cestode Taenia solium develops as a tapeworm solely in the human intestine, starting from a larva (cyst). Upon maturing, it produces hundreds of thousands of infectious eggs. When ingested by pigs or humans, the eggs develop as cysts that lodge in various tissues, including the brain, leading to neurocysticercosis. Despite advances in understanding cestode biology through genomic and transcriptomic studies, particularly in model organisms, much remains unknown about the activation of T. solium cysts in the human digestive tract and the events that drive the development into adult worms-the stage responsible for dispersing the parasite. We present a transcriptome generated by Next Generation Sequencing from T. solium cysts activated in culture and collected at three different in vitro growth phases, defined by their morphology. Differentially expressed genes and biological processes relevant to activation and growth can be explored with the dataset. The information is valuable for identifying genes that regulate the molecular, metabolic, and cellular events leading to parasite maturation or elements driving its transmission.

Fig. 1

Experimental design and morphological phases of T. solium cysts around the evagination of the scolex in vitro. (a) Overview of the in vitro culture and sampling strategy. T. solium cysts from naturally infected pigs were cultured in RPMI medium at 37 °C with 5% CO₂. Taurocholic acid (TA) was added at time zero. Samples collected at three distinct moments correspond to different morphological phases around scolex evagination: PRE (6 h in vitro), EV (24–48 h in vitro), and POST (120 h in vitro). RNA extraction, cDNA synthesis, and bulk RNA sequencing followed. Bioinformatic analyses included quality control (FastQC), alignment (Rsubread), gene quantification (GenomicFeatures), and statistical analysis (DESeq 2). (b) Representative images of cysts from each group.

Fig. 2

Quality control and validation analysis of transcriptomic data across cyst developmental phases and TA treatment. (a) Principal Component Analysis (PCA) plot showing global transcriptomic variation among samples. Samples cluster primarily by parasite group and phase (represented by colors) and secondarily by TA treatment (denoted by outlined circles). (b) Hierarchical clustering heatmap of sample-to-sample distances based on variance-stabilized transformed counts. Clustering reflects developmental phases and TA conditions, supporting the consistency of sample grouping. (c) Sequencing depth (mapped reads) per replicate, with or without TA treatment (bar plot) and overall distribution (boxplot). Read counts range from approximately 9 to 31 million per sample, with a median of ~14.5 million. (d) MA plots displaying the shrunk log₂ fold-change relative to the log₁₀ of mean normalized counts, comparing EV vs. PRE in the absence (left) and presence (right) of TA.