I have collected Nanogrid Single-Nucleus RNA Sequencing data from an already published study. While checking the top 20 highly variable genes using the Seurat package, I am getting a bunch of microRNA genes (eg: MIR1244-1) and RNA genes (eg: SNAR-B1). I am confused here because I thought it is impossible to capture microRNA gene expression using the 10X workflow because mature microRNA (miRNA) transcripts lack a polyA tail. What am I missing?