Retention of the last intron

Here are a few publications addressing Morpholinos and retention of the last intron.

See the section: Retention of wnt11b Intron 4 Recapitulates the Failure to Form Somites in tra2b Morphants
Dichmann DS, Walentek P, Harland RM. The Alternative Splicing Regulator Tra2b Is Required for Somitogenesis and Regulates Splicing of an Inhibitory Wnt11b Isoform. Cell Rep. 2015 Jan 21. pii: S2211-1247(14)01099-7. doi: 10.1016/j.celrep.2014.12.046. [Epub ahead of print].
http://www.ncbi.nlm.nih.gov/pubmed/25620705

Forcing a terminal intron inclusion:
Shchelkunova A, Ermolinsky B, Boyle M, Mendez I, Lehker M, Martirosyan KS, Kazansky AV. Tuning of Alternative Splicing - Switch From Proto-Oncogene to Tumor Suppressor. Int J Biol Sci. 2013;9(1):45-54. doi:10.7150/ijbs.5194.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3535533/

Blocking regulatory elements to increase intron retention:
Parra M, Yeo G, Conboy JG. Intron Retention Mechanisms That Regulate SF3B1 and Mitoferrin Gene Expression during Late Erythropoiesis. Blood. 2016;128:1200.
http://www.bloodjournal.org/content/128/22/1200