Purifying selection against spurious splicing signals contributes to the base composition evolution of the polypyrimidine tract.

ABSTRACT: Among eukaryotes, the major spliceosomal pathway is highly conserved. While long introns may contain additional regulatory sequences, the ones in short introns seem to be nearly exclusively related to splicing. Although these regulatory sequences involved in splicing are well-characterized, little is known about their evolution. At the 3' end of introns, the splice signal nearly universally contains the dimer AG, which consists of purines, and the polypyrimidine tract upstream of this 3' splice signal is characterized by over-representation of pyrimidines. If the over-representation of pyrimidines in the polypyrimidine tract is also due to avoidance of a premature splicing signal, we hypothesize that AG should be the most under-represented dimer. Through the use of DNA-strand asymmetry pat

SUBMITTER: Yıldırım B 

PROVIDER: S-EPMC10946897 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature