title: Blastocyst formation is blocked in mouse embryos lacking the splicing factor SRp20.
abstract: SRp20 is a splicing factor belonging to the highly conserved family of SR proteins [1] [2] [3] [4], which have multiple roles in the regulation of constitutive and alternative splicing in vivo. It has been suggested that SR proteins are involved in bringing together the splice sites during spliceosome assembly [5]. SR proteins show partial redundancy, as each single SR protein can restore splicing activity to a splicing-deficient cytoplasmic extract (termed S-100 extract). Nevertheless, several studies demonstrate that individual SR proteins have different effects on the selection of specific alternative splice sites, and they recognize distinct RNA sequences [6] [7] [8] [9] [10] [11] [12]. Also, inactivation of two SR proteins, B52/SRp55 in Drosophila [13] or ASF/SF2 in the chicken cell line DT40 [14], is lethal, indicating the existence of nonredundant functions. Here, using Cre-loxP-mediated recombination in mice to inactivate the SRp20 gene, we found that it is essential for mouse development. Mutant preimplantation embryos failed to form blastocysts and died at the morula stage. Immunofluorescent staining showed that SRp20 is present in oocytes and early stages of embryonic development. This is the first report of mice deficient for a member of the SR protein family. Our experiments confirm that, although similar in structure, the SR proteins are not functionally redundant.
authors.affiliation: Max Planck Institute for Immunobiology, Stuebeweg 51, D-79108, Freiburg i. Br, Germany. jumaa@immunbio.mpg.de
authors.forename: H
authors.initials: H
authors.lastname: Jumaa
authors.forename: G
authors.initials: G
authors.lastname: Wei
authors.forename: P J
authors.initials: PJ
authors.lastname: Nielsen
mesh_terms: D000483:Alleles; D000818:Animals; D001755:Blastocyst / Q000737:chemistry; D018274:Electroporation; D047108:Embryonic Development; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D005455:Fluorescent Antibody Technique; D017353:Gene Deletion; D005838:Genotype; D051379:Mice; D009028:Morula / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D016601:RNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D000068103:Serine-Arginine Splicing Factors; D013997:Time Factors
chemical_list: D016601:RNA-Binding Proteins; C106161:Srsf3 protein, mouse; D000068103:Serine-Arginine Splicing Factors