Comparison of CRISPR Sequences in Archaea and Bacteria with Eukaryotic microRNAs

This study explores repetitive Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) sequences from the archaea Acidianus sp. and Acidianus ambivalens (A. ambivalens), as well as from the bacterium Yersinia ruckeri (Y. ruckeri). These sequences are compared with human microRNA (miRNA) sequences to investigate potential genetic similarities and disease associations.

CRISPR sequences were retrieved from the CRISPR/Cas⁺⁺ database, and human miRNA sequences were obtained from miRBase. Sequence alignments were performed using BLASTn with an E-value threshold of 1e-5 to identify significant similarities. Genes associated with matched human miRNAs were identified through the HGNC and GeneCards databases. Further analyses included comparison with disease-associated miRNAs reported in human and mouse datasets.

In Y. ruckeri, alignments revealed similarities to miRNAs linked with genes such as FOXO1, PTEN, PAX7, and DOCK3, which are associated with lung cancer and muscular dystrophies. In A. ambivalens, aligned miRNAs corresponded to loci including CHM13 and GRCh38, potentially linked to periembolic adenocarcinoma and mild pre-eclampsia. For Acidianus sp., matches were observed with miRNAs associated with genes like Irak2, NOS2, STAT1, and Numb, which have been implicated in Psoriatic arthritis, Alzheimer's disease, Hepatocellular carcinoma, and Coronary artery disease.

CRISPR sequences from these prokaryotes show notable similarities with human miRNAs, suggesting possible indirect links to genes involved in major diseases. These preliminary findings emphasize the need for further investigation into shared sequence motifs and their functional roles in host-pathogen interactions or evolutionary biology.