title: RNA Binding Protein Ptbp2 Is Essential for Male Germ Cell Development.
abstract: RNA binding proteins (RBPs) are increasingly recognized as essential factors in tissue development and homeostasis. The polypyrimidine tract binding (PTB) protein family of RBPs are important posttranscriptional regulators of gene expression. In the nervous system, the function and importance of PTB protein 2 (Ptbp2) as a key alternative splicing regulator is well established. Ptbp2 is also abundantly expressed during spermatogenesis, but its role in this developmental program has not been explored. Additionally, the importance of alternative splicing regulation in spermatogenesis is unclear. Here, we demonstrate that Ptbp2 is essential for spermatogenesis. We also describe an improved dual fluorescence flow cytometry strategy to discriminate, quantify, and collect germ cells in different stages of development. Using this approach, in combination with traditional histological methods, we show that Ptbp2 ablation results in germ cell loss due to increased apoptosis of meiotic spermatocytes and postmeiotic arrest of spermatid differentiation. Furthermore, we show that Ptbp2 is required for alternative splicing regulation in the testis, as in brain. Strikingly, not all of the alternatively spliced RNAs examined were sensitive to Ptbp2 loss in both tissues. Collectively, the data provide evidence for an important role for alternative splicing regulation in germ cell development and a central role for Ptbp2 in this process.
authors.affiliation: Center for RNA Molecular Biology, Case Western Reserve University, Cleveland, Ohio, USA Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Leah L
authors.initials: LL
authors.lastname: Zagore
authors.affiliation: Center for RNA Molecular Biology, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Grabinski
authors.affiliation: Center for RNA Molecular Biology, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Sweet
authors.affiliation: Center for RNA Molecular Biology, Case Western Reserve University, Cleveland, Ohio, USA Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Molly M
authors.initials: MM
authors.lastname: Hannigan
authors.affiliation: Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: R Michael
authors.initials: RM
authors.lastname: Sramkoski
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA.
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.affiliation: Center for RNA Molecular Biology, Case Western Reserve University, Cleveland, Ohio, USA Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA ddl33@case.edu.
authors.forename: Donny D
authors.initials: DD
authors.lastname: Licatalosi
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D002478:Cells, Cultured; D005260:Female; D017353:Gene Deletion; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008297:Male; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D038941:Polypyrimidine Tract-Binding Protein / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D013091:Spermatogenesis; D013094:Spermatozoa / Q000166:cytology* / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000378:metabolism
chemical_list: D009419:Nerve Tissue Proteins; C429773:Ptbp2 protein, mouse; D012333:RNA, Messenger; D038941:Polypyrimidine Tract-Binding Protein