Comprehensive Transcriptome Analysis of Sex-Biased Expressed Genes Reveals Discrete Biological and Physiological Features of Male and Female Schistosoma japonicum

Abstract

Schistosomiasis is a chronic and debilitating disease caused by blood flukes (digenetic trematodes) of the genus Schistosoma. Schistosomes are sexually dimorphic and exhibit dramatic morphological changes during a complex lifecycle which requires subtle gene regulatory mechanisms to fulfil these complex biological processes. In the current study, a 41,982 features custom DNA microarray, which represents the most comprehensive probe coverage for any schistosome transcriptome study, was designed based on public domain and local databases to explore differential gene expression in S. japonicum. We found that approximately 1/10 of the total annotated genes in the S. japonicum genome are differentially expressed between adult males and females. In general, genes associated with the cytoskeleton, and motor and neuronal activities were readily expressed in male adult worms, whereas genes involved in amino acid metabolism, nucleotide biosynthesis, gluconeogenesis, glycosylation, cell cycle processes, DNA synthesis and genome fidelity and stability were enriched in females. Further, miRNAs target sites within these gene sets were predicted, which provides a scenario whereby the miRNAs potentially regulate these sex-biased expressed genes. The study significantly expands the expressional and regulatory characteristics of gender-biased expressed genes in schistosomes with high accuracy. The data provide a better appreciation of the biological and physiological features of male and female schistosome parasites, which may lead to novel vaccine targets and the development of new therapeutic interventions.

Transcriptomic analysis of male and female Schistosoma mekongi adult worms

“…Genes encoding cytoskeleton-, motor- and neuronal-associated proteins (dynein, tropomyosin 2, myosin light chain kinase and plexin A1) were predominantly upregulated in male worms. Our findings are consistent with previous studies of S. mansoni and S. japonicum [ 20 , 21 , 23 , 49 – 51 ]. Upregulation of cytoskeleton and motor proteins in male worms may imply their role in the physical support of female worms to facilitate their migration against blood flow from hepatic portal sites to the smaller mesenteric circulation where they lay their eggs [ 24 ].…”

Histone deacetylase inhibition modulates histone acetylation at gene promoter regions and affects genome-wide gene transcription in Schistosoma mansoni

“…Recently, a report on S . japonicum genes differentially expressed between genders has shown that a total of 685 and 430 genes were detected in males and females, respectively, as having significant fold-change values ≥ 2 simultaneously in the forward and the reverse strand [62]. Our results confirm that also in S .…”

A next-generation microarray further reveals stage-enriched gene expression pattern in the blood fluke Schistosoma japonicum

“…However, two pre-requisites for egg production are mating and nutrient acquisition. In fulfilment of the former process, the gene encoding gynecophoral canal protein has been shown upregulated in adults, with a dramatic bias towards male worms [59]. In regards to nutrient uptake, and consistent with a previous study [18], over-expression of a number of ‘blood processing’ proteases in adult worms was also revealed here.…”

“…Most of these genes are female-biased expressed genes [59] with potential molecular functions in egg production [60]. …”