While studies of alternative pre-mRNA splicing regulation have typically focused 
on RNA-binding proteins and their target sequences within nascent message, it is 
becoming increasingly evident that mRNA splicing, RNA polymerase II (pol II) 
elongation and chromatin structure are intricately intertwined. The majority of 
introns in higher eukaryotes are excised prior to transcript release in a manner 
that is dependent on transcription through pol II. As a result of 
co-transcriptional splicing, variations in pol II elongation influence 
alternative splicing patterns, wherein a slower elongation rate is associated 
with increased inclusion of alternative exons within mature mRNA. Physiological 
barriers to pol II elongation, such as repressive chromatin structure, can 
thereby similarly impact splicing decisions. Surprisingly, pre-mRNA splicing can 
reciprocally influence pol II elongation and chromatin structure. Here, we 
highlight recent advances in co-transcriptional splicing that reveal an 
extensive network of coupling between splicing, transcription and chromatin 
remodeling complexes. This article is part of a Special Issue entitled: 
Chromatin in time and space.