Abstract: The present disclosure relates to a recombinant nucleic acid molecule and an application thereof in preparation of a circular RNA, and in particular, to a recombinant nucleic acid molecule for preparing a circular RNA, a recombinant expression vector, a circular RNA, a composition, a method for preparing a circular RNA, a method for expressing a target polypeptide in a cell, a method for screening a target coding region sequence, a system for screening a target coding region sequence, and a method for screening a ribozyme recognition site sequence.

Abstract: The present disclosure relates to a recombinant nucleic acid molecule based on point mutation of translation initiation element and use thereof in the preparation of circular RNA, and in particular to a recombinant nucleic acid molecule for preparing circular RNA, a recombinant expression vector, circular RNA, a composition, a method for preparing circular RNA, a method for expressing a target polypeptide in a cell, a method for preventing or treating a disease, a method for editing a translation initiation element sequence, and a system for editing a translation initiation element sequence.

Abstract: The disclosure belongs to the technical field of bioinformatics and bioengineering, and specifically, relates to a Levenshtein distance-based IRES screening method, a polynucleotide screened based on this method, a circular nucleic acid molecule including the polynucleotide, a cyclization precursor nucleic acid molecule, a recombinant nucleic acid molecule, a recombinant expression vector, a recombinant host cell, and use. In the disclosure, averages of Levenshtein distances between all sample sequences and to-be-predicted sequences are compared, to efficiently and accurately determine whether there is an IRES in the to-be-predicted sequence, which has advantages of high efficiency and an accurate screening result.

Abstract: The present disclosure belongs to the technical field of bio-medicine, particularly, the present disclosure relates to a tissue-specifically expressed circular RNA molecule, a cyclization precursor RNA molecule, a recombinant nucleic acid molecule, a recombinant expression vector, a recombinant host cell, a composition, a pharmaceutical preparation and application thereof in preparation of a drug for preventing or treating diseases, as well as a method for preventing or treating diseases. The circular RNA molecule provided by the present disclosure operably links a coding region to an expression regulatory element, realizing specific high expression of a target polypeptide in target cells or target tissues, and low expression of the target polypeptide in non-target cells or non-target tissues, and having high tissue expression specificity, thereby providing a safe and effective treatment strategy for clinical targeted therapy of diseases such as tumors.