title: Interconversion of germline-limited and somatic DNA in a scrambled gene.
abstract: Ciliates have a somatic and a germline nucleus; after sexual conjugation a new somatic nucleus forms from the new zygotic germline nucleus. Formation of the somatic nucleus involves precise elimination of a large portion of DNA sequences from the germline. Here we compare the architecture of the germline and somatic versions of the actin I gene in two geographically isolated strains of Stylonychia lemnae. We show that the structure of the germline gene is surprisingly mercurial, with the distinction between germline-limited and somatic sequences variable over the course of evolution. This is, to our knowledge, the first example of evolutionary swapping of retained versus deleted sequences during ciliate development, with sequences deleted during development that are specifically retained in another strain.
authors.affiliation: Institute of Cell Biology, Witten/Herdecke University, 58448, Witten, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Möllenbeck
authors.forename: Andre R O
authors.initials: AR
authors.lastname: Cavalcanti
authors.forename: Franziska
authors.initials: F
authors.lastname: Jönsson
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Lipps
authors.forename: Laura F
authors.initials: LF
authors.lastname: Landweber
mesh_terms: D000199:Actins / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D016798:Ciliophora / Q000235:genetics*; D004247:DNA / Q000032:analysis; D005785:Gene Conversion; D017125:Genes, Protozoan; D018503:Genome, Protozoan; D048631:Micronucleus, Germline / Q000235:genetics*; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D000199:Actins; D004247:DNA