MicroRNAs Are Involved in the Regulation of Ovary Development in the Pathogenic Blood Fluke Schistosoma japonicum

Abstract

Schistosomes, blood flukes, are an important global public health concern. Paired adult female schistosomes produce large numbers of eggs that are primarily responsible for the disease pathology and critical for dissemination. Consequently, understanding schistosome sexual maturation and egg production may open novel perspectives for intervening with these processes to prevent clinical symptoms and to interrupt the life-cycle of these blood-flukes. microRNAs (miRNAs) are key regulators of many biological processes including development, cell proliferation, metabolism, and signal transduction. Here, we report on the identification of Schistosoma japonicum miRNAs using small RNA deep sequencing in the key stages of male-female pairing, gametogenesis, and egg production. We identified 38 miRNAs, including 10 previously unknown miRNAs. Eighteen of the miRNAs were differentially expressed between male and female schistosomes and during different stages of sexual maturation. We identified 30 potential target genes for 16 of the S. japonicum miRNAs using antibody-based pull-down assays and bioinformatic analyses. We further validated some of these target genes using either in vitro luciferase assays or in vivo miRNA suppression experiments. Notably, suppression of the female enriched miRNAs bantam and miR-31 led to morphological alteration of ovaries in female schistosomes. These findings uncover key roles for specific miRNAs in schistosome sexual maturation and egg production.

First Report of Aleurocanthus spiniferus on Ailanthus altissima: Profiling of the Insect Microbiome and MicroRNAs

“…We retained only reads with length ranging from 15 to 35 nt, and their length distribution is shown in Figure 3. Frequency peaks were observed for sRNAs of 21 and 28 nt, in agreement with previous works on B. tabaci B and Q biotypes or other insects [64][65][66]. Thirty-six percent reads between 19 and 22 nt mapped to miRNAs, while 74% of 28 nt reads were unassigned ( Figure 3B).…”

“…MicroRNA bantam promotes cell proliferation, inhibits apoptosis, maintains germline stem cells, limits scaling growth of dendrites, and regulates circadian rhythm clock [66,71,72]. MicroRNA miR-8 prevents neurodegeneration in the brain, is involved in the development of wings and eyes, promotes organismal growth in larvae, and controls the morphology of neuromuscular junctions [71].…”

microRNA analysis of Taenia crassiceps cysticerci under praziquantel treatment and genome-wide identification of Taenia solium miRNAs

“…Identifying the function of specific miRNAs in parasitic species by experimental approaches is not an easy task (Xia et al, 2009) since in vitro culture and RNA interference (RNAi) systems have been successfully accomplished for only a few species (Mizukami et al, 2010;Bai et al, 2014;Wang et al, 2014;Guidi et al, 2015). As a first step to experimental validation, bioinformatic prediction of miRNA targets has been performed for a number of helminth parasites (Huang et al, 2009;Fu et al, 2013;Bai et al, 2014;Winter et al, 2015;Ma et al, 2016;Zhu et al, 2016). However, there is no information on miRNA targeted genes in the genus Taenia.…”

Epigenetics in Schistosomes: What We Know and What We Need Know

“…Thirteen microRNAs exhibit sex-biased expression, 10 of which are more abundant in females than in males, such as mir-31, mir-8447, bantam and mir-8437 (Marco et al, 2013). The miRNAs bantam and miR-31 are associated with the morphological formation of ovaries in female schistosomes in S. japonicum (Zhu et al, 2016). These results demonstrate that during the life cycle of schistosomes, different microRNAs are likely to participate in differentiation/maintenance processes.…”