Comparative profiling of microRNAs in male and female adults of Ascaris suum

Abstract

Ascaris nematodes, which cause ascariasis in humans and pigs, are among the most important nematodes from both health and economic perspectives. microRNA (miRNA) is now recognized as key regulator of gene expression at posttranscription level. The public availability of the genome and transcripts of Ascaris suum provides powerful resources for the research of miRNA profiles of the parasite. Therefore, we investigated and compared the miRNA profiles of male and female adult A. suum using Solexa deep sequencing combined with bioinformatic analysis and stem-loop reverse transcription polymerase chain reaction. Deep sequencing of small RNAs yielded 11.71 and 11.72 million raw reads from male and female adults of A. suum, respectively. Analysis showed that the noncoding RNA of the two genders, including tRNA, rRNA, snRNA, and snoRNA, were similar. By mapping to the A. suum genome, we obtained 494 and 505 miRNA candidates from the female and male parasite, respectively, and 87 and 82 of miRNA candidates were consistent with A. suum miRNAs deposited in the miRBase database. Among the miRNA candidates, 154 were shared by the two genders, and 340 and 351 were female and male specific with their target numbers ranged from one to thousands, respectively. Functional prediction revealed a set of elongation factors, heat shock proteins, and growth factors from the targets of gender-specific miRNAs, which were essential for the development of the parasite. Moreover, major sperm protein and nematode sperm cell motility protein were found in targets of the male-specific miRNAs. Ovarian message protein was found in targets of the female-specific miRNAs. Enrichment analysis revealed significant differences among Gene Ontology terms of miRNA targets of the two genders, such as electron carrier and biological adhesion process. The regulating functions of gender-specific miRNAs was therefore not only related to the fundamental functions of cells but also were essential to the germ development of the parasite. The present study provides a framework for further research of Ascaris miRNAs, and consequently leads to the development of potential nucleotide vaccines against Ascaris of human and animal health significance.

Sex-Biased Expression of MicroRNAs in Schistosoma mansoni

“…This is in agreement with the overall female-bias observed for protein-coding genes in both S. mansoni [10] and S. japonicum [11], although a recent expression analysis in S. japonicum showed no gender bias [13]. Recently, a work in the parasitic nematode Ascaris suum showed that microRNAs are differentially expressed between males and females [32]. Although the differences were small and the targeting properties of male and female microRNAs similar, they reported a tendency of male microRNA to target extracellular proteins [32].…”

Human platelet microRNA-mRNA networks associated with age and gender revealed by integrated plateletomics

“…42 Metallothionein genes or pseudogenes were 4 of the 9 mRNAs showing the highest expression in women in PRAX1 (supplemental Table 7A), perhaps due to estrogeninduced increase in cadmium levels that transcriptionally upregulate metallothionein genes. 43 Although miRNAs have been reported to be DE by gender in the Ascaris nematode, 44 we are unaware of prior reports of human miRNA profile comparisons of gender differences in any tissue. In PRAX1, we observed 2 of the 9 miRNAs DE by gender were more highly expressed in women.…”

Micromanagement of Immune System: Role of miRNAs in Helminthic Infections

“…Their germline is siRNA pathway dependent, whereas embryogenesis and larval development is dependent on miR pathway. The miR expression profile of male and female worm shared two novel miRs Asu-miR-share-391 and Asu-miR-share-404, the expression of miR-391 was more abundant in male than in female (Xu et al, 2013b). But their role in immune regulation needs to be further investigated.…”

“…The comparative miR expression profile of these two species had revealed 13 species-specific miRs that matched with miR4006b of Ciona intestinalis and miR 1957 matched with Mus musculus . Other miRs that could map to metabolic regulation and catalytic and binding function were common to both species (Xu et al, 2013b). Fromm et al (2015) used deep-sequencing method and identified 54 miRNA (42conserved and 13 novel) and isolated miR from extracellular vesicles (EV) also.…”