ABSTRACT
Objective To compare the differences in pathogenicity and gene expression profiles between adult Schistosoma japonicum isolated from hilly and marshland and lake regions of Anhui Province, so as to provide the scientific evidence for formulating the precise schistosomiasis control strategy in different endemic foci. Methods C57BL/6 mice were infected with cercariae of S. japonicum isolates from Shitai County (hilly regions) and Susong County (marshland and lake regions) of Anhui Province in 2021, and all mice were sacrificed 44 days post-infection and dissected. The worm burdens, number of S. japonicum eggs deposited in the liver, and the area of egg granulomas in the liver were measured to compare the difference in the pathogenicity between the two isolates. In addition, female and male adult S. japonicum worms were collected and subjected to transcriptome sequencing, and the gene expression profiles were compared between Shitai and Susong isolates of S. japonicum. The differentially expressed genes (DEGs) were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Results The total worm burdens [(14.50 ± 3.96) worms/mouse vs. (16.10 ± 3.78) worms/mouse; t = 0.877, P = 0.392], number of female and male paired worms [(4.50 ± 0.67) worms/mouse vs. (5.10 ± 1.45) worms/mouse; t = 1.129, P = 0.280], number of unpaired male worms [(5.50 ± 4.01) worms/mouse vs. (5.60 ± 1.69) worms/mouse; t = 0.069, P = 0.946], number of eggs deposited in per gram liver [(12 116.70 ± 6 508.83) eggs vs. (16 696.70 ± 4 571.56) eggs; t = 1.821, P = 0.085], and area of a single egg granuloma in the liver [(74 359.40 ± 11 766.34) µm2 vs. (74 836.90 ± 13 086.12) µm2; t = 0.081, P = 0.936] were comparable between Shitai and Susong isolates of S. japonicum. Transcriptome sequencing identified 584 DEGs between adult female worms and 1 598 DEGs between adult male worms of Shitai and Susong isolates of S. japonicum. GO enrichment analysis showed that the DEGs between female adults were predominantly enriched in biological processes of stimulus response, cytotoxicity, multiple cell biological processes, metabolic processes, cellular processes and signaling pathways, cellular components of cell, organelles and cell membranes and molecular functions of binding and catalytic ability, and KEGG enrichment analysis showed that these DEGs were significantly enriched in pathways of vascular endothelial growth factor signaling, glutathione metabolism, arginine and proline metabolism. In addition, the DEGs between male adults were predominantly enriched in biological processes of signaling transduction, multiple cell biological processes, regulation of biological processes, metabolic processes, development processes and stimulus responses, cellular components of extracellular matrix and cell junction and molecular functions of binding and catalytic ability, and these DEGs were significantly enriched in pathways of Wnt signaling, Ras signaling, natural killer cells-mediated cytotoxicity, extracellular matrix-receptor interactions and arginine biosynthesis. Conclusions There is no significant difference in the pathogenicity between S. japonicum isolates from hilly and marshland and lake regions of Anhui Province; however, the gene expression profiles vary significantly between S. japonicum isolates.
ABSTRACT
Objective To characterize the epidermal growth factor receptor (EGFR) gene in Schistosoma japonicum (SjEGFR gene) and investigate the role of the EGFR gene in regulating the growth, reproductive system, maturation and fecundity of S. japonicum. Methods Rapid amplification of cDNA ends (RACE) was performed to obtain the full length of the SjEGFR gene, and the SjEGFR gene expression was quantified in different developmental stages of S. japonicum using a quantitative real-time PCR (qPCR) assay. The tissue localization of the SjEGFR gene was detected in 22-day parasite using whole-mount in situ hybridization (WISH). Following RNA interference (RNAi)-induced knockdown of the SjEGFR gene, the worm length, pairing rate and worm burden of S. japonicum were measured, and the worm morphology was observed using optical microscopy and confocal microscopy. Results The SjEGFR gene was identified with a conserved tyrosine-kinase active site, and the SjEGFR gene expression was detected at various developmental stages in male and female parasites. WISH showed that the transcript of the SjEGFR gene was localized on the tegument and in the digestive organs of S. japonicum. RNAi-induced SjEGFR knockdown resulted in marked suppression of the worm growth, smaller size of male testicles that contained more immature spermatocytes, and apparent impairment of ovary and vitelline gland development. In addition, no eggs were found in the uterus of SjEGFR knocked-down female parasites, indicating the interruption of egg production. Conclusions Inhibition of SjEGFR expression may remarkably suppress the growth and maturation of S. japonicum, and interrupt the egg production.