Sam68 insures proper 3'-end pre-mRNA processing during germ cell differentiation

Male germ cells express the widest repertoire of transcript variants in mammalian tissues. Nevertheless, factors and mechanisms underlying such pronounced diversity are largely unknown. The splicing regulator Sam68 is highly expressed in meiotic cells and its ablation results in defective spermatogenesis. Herein, we uncover an extensive splicing program operated by Sam68 across meiosis, primarily characterized by alternative last exon (ALE) regulation in genes of functional relevance for spermatogenesis. Lack of Sam68 preferentially causes premature transcript termination at internal polyadenylation sites. RNA‐Seq data for purified spermatocytes and spermatids isolated from Sam68+/+ and Sam68-/- mice.