In theory it should be easiest to deduce the origin of recently gained introns due to the lack of host-induced mutations, yet even introns gained recently did not arise from any of the aforementioned mechanisms. These findings thus raise the question of whether or not the proposed mechanisms of intron gain fail to describe the mechanistic origin of many novel introns because they are not accurate mechanisms of intron gain, or if there are other, yet to be discovered, processes generating novel introns.In intron transposition, the most commonly purported intron gain mechanism, a spliced intron is thought to reverse splice into either its own mRNA or another mRNA at a previously intron-less position. This intron-containing mRNA is then reverse transcribed and the resulting intron-containing cDNA may then cause intron gain via complete or partial recombination with its original genomic locus. Transposon insertions can also result in intron creation. Such an insertion could intronize the transposon without disrupting the coding sequence when a transposon inserts into the sequence AGGT, resulting in the duplication of this sequence on each side of the transposon. It is not yet understood why these elements are spliced, whether by chance, or by some preferential action by the transposon. In tandem genomic duplication, due to the similarity between consensus donor and acceptor splice sites, which both closely resemble AGGT, the tandem genomic duplication of an exonic segment harboring an AGGT sequence generates two potential splice sites.
Revefenacin, sold under the brand name Yupelri, is a medication for the treatment of chronic obstructive pulmonary disease (COPD). It was approved for use in the United States in 2018. It was developed by Theravance Biopharma and is marketed by Mylan. Revefenacin is formulated as a solution that is nebulized and inhaled.Revefenacin is a bronchodilator that exerts its effect as a long-acting muscarinic antagonist. References
External links
"Revefenacin". Drug Information Portal. U.S. National Library of Medicine.