Abstract
microRNAs (miRNAs) are an abundant class of non-coding RNA species with important regulatory roles in gene expression at the posttranscriptional level. The helminth Acanthocheilonema viteae serves as model organism for research on parasitic filarial nematodes. Total RNA secreted or excreted in vitro by 1500 adult female and male A. viteae over 3 weeks was isolated from culture media previously processed by differential ultracentrifugation. miRNA sequencing revealed the presence of 360 unique miRNA candidates released by adult A. viteae in vitro. Among them, 74 high-confidence unique miRNAs, as well as several potential novel miRNA candidates were discovered. A large proportion of the sequenced miRNA candidates appeared differentially expressed between the male and female samples based on normalized copy count. The presence of extracellular vesicles, often rich in miRNAs, could not be confirmed unambiguously by transmission electron microscopy.