Transcriptomic differences between larval stages of Anisakis simplex (s.s)

The herring worm, Anisakis simplex, is a parasitic nematode of marine mammals characterized by a complex life cycle. The presence of invasive larvae of this parasite has been documented in 200 species of fish and 25 species of cephalopods around the world. Parasitic nematodes of the genus Anisakis are responsible for a human disease called anisakiasis. A. simplex has been recognized as a biohazardous organism and knowledge of the full spectrum of RNAs transcribed and expressed by this parasite is needed. Changes in the biology and epidemiology of Anisakis species may be exacerbated by the ever-changing environment. This could lead to an expansion of the areas where the genus Anisakis is found and an increase in the number of infected host species due to molecular changes in their transcriptome, further justifying our attention to anisakiasis. In this study, we used high-throughput RNA-Seq data and bioinformatics to characterize the mRNA expression patterns of two larval stages (L3 and L4) of A. simplex from two different geographical regions (Baltic and Atlantic populations). In this paper, we present the transcriptomic analysis of L3 and L4 larval stages of A. simplex s. s. from two different geographical regions: the Galician coast of the north-east Atlantic (Ria de Vigo, Spain) and the Polish coast of the south-east Baltic Sea (Wladyslawowo, Poland). In addition, we have identified a number of long non-coding RNAs that are mainly expressed to regulate the expression of other genes. Taken together, these results can help us to better understand the rapidly growing population of this species in different geographical areas, regardless of different climatic conditions and different host species. This work was supported by the National Science Centre of Poland, grant no. 2018/31/B/NZ9/01683.