16S metabarcoding sequences of Littorina obtusata microbiome: intestinal tissue
Infected and uninfected (with M. pygmaeus trematodes) molluscs Littorina saxatilis and L. obtusatawere collected in August 2021 at the Barents sea, Oscar Bay, Dalnye Zelentsy; N 69.117, E 36.070, from the upper and the lower shore level separately. The molluscs were dissected in the laboratory, and snail intestines were fixed in 70% ethanol individually. The DNA extraction from dissected guts of the infected and uninfected individuals of L. saxatilis and L. obtusata was performed with the DNeasy PowerSoil kit (QIAGEN). The 16S rDNA libraries preparation for the Illumina MiSeq sequencing (Evrogen) included the following steps: [1] the locus-specific PCR, using 515F and 806R primers from Caporaso et al. 2011; [2] the amplicon clean-up with the magnetic beads (Evrogen); [3] the indexing PCR and the 2nd clean-up with the magnetic beads; [4] the final pooling.