Welcome to the Minor Intron Database (MIDB), created by the Kanadia Lab at the University of Connecticut. Our lab studies the dynamics of minor intron splicing and its effect on development. Minor introns, or U12-type introns were initially identified based on their divergent terminal dinucleotide sequences (Jackson, 1991). Soon thereafter, it was found that these introns in fact contained an entirely different 5’ splice site and branch point sequence compared to the other class of introns, called major introns (Hall and Padgett, 1994; Dietrich et al., 1997). As such, these minor introns could not be spliced by the major spliceosome. Indeed, the Steitz lab then identified several components of a different splicing machinery, which could splice these minor introns, and this was called the minor spliceosome (Tarn and Steitz, 1996).

This database can assist you in identifying minor introns in over 270 species across a phylogenetically diverse subset of eukaryotes. We provide a taxonomic breakdown of introns based on the nucleic acid sequence at their splice-sites using position-weight matrices. While the database primarily focuses on minor introns, data is included for all intron types including minor, minor-like, minor-hybrid, major-hybrid, major-like, major, and non-canonical. In addition to intron classification, the MIDB includes an extensive orthology network on the gene, protein and intron level. All data sources are included at the gene level and will be updated regularly as needed, with the most recent update date included below. For more information regarding the classification scheme please reference: (Olthof and Schwoerer et al., in preparation, 2022).

If you have used any information obtained from the MIDB for your own research, we ask you to please cite: (Olthof et al., 2019) and (Olthof and Schwoerer et al., in preparation, 2022).

MIDB search functionality is split into basic and advanced search pages. The basic search page allows a user to search on species, gene and transcript. This returns all matching genes and transcripts. The user can click on the respective hyperlink to view any level of the gene, transcript and associated introns. The advanced search page allows for more flexibility in your search, with new functionality added as the need arises. If you would like to make any suggestions regarding desired search functionality, please contact the email provided below. Users can also download all data within the database. Data is stored in zip files on the download pages and organized by species. Further instructions for each of these pages can be found at the top of the respective page.

If you would like to learn more about our research, please visit our website at kanadialab.uconn.edu. For all comments and questions, please contact: rahul.kanadia@uconn.edu