title: Drosophila Nnf1 paralogs are partially redundant for somatic and germ line kinetochore function.
abstract: Kinetochores allow attachment of chromosomes to spindle microtubules. Moreover, they host proteins that permit correction of erroneous attachments and prevent premature anaphase onset before bi-orientation of all chromosomes in metaphase has been achieved. Kinetochores are assembled from subcomplexes. Kinetochore proteins as well as the underlying centromere proteins and the centromeric DNA sequences evolve rapidly despite their fundamental importance for faithful chromosome segregation during mitotic and meiotic divisions. During evolution of Drosophila melanogaster, several centromere proteins were lost and a recent gene duplication has resulted in two Nnf1 paralogs, Nnf1a and Nnf1b, which code for alternative forms of a Mis12 kinetochore complex component. The rapid evolutionary divergence of centromere/kinetochore constituents in animals and plants has been proposed to be driven by an intragenome conflict resulting from centromere drive during female meiosis. Thus, a female meiosis-specific paralog might be expected to evolve rapidly under positive selection. While our characterization of the D. melanogaster Nnf1 paralogs hints at some partial functional specialization of Nnf1b for meiosis, we have failed to detect evidence for positive selection in our analysis of Nnf1 sequence evolution in the Drosophilid lineage. Neither paralog is essential, even though we find some clear differences in subcellular localization and expression during development. Loss of both paralogs results in developmental lethality. We therefore conclude that the two paralogs are still in early stages of differentiation.
authors.affiliation: Institute of Molecular Life Sciences (IMLS), University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
authors.forename: Ariane C
authors.initials: AC
authors.lastname: Blattner
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.|Swiss Institute of Bioinformatics (SIB), Quartier Sorge, Bâtiment Génopode, 1015, Lausanne, Switzerland.
authors.forename: José
authors.initials: J
authors.lastname: Aguilar-Rodríguez
authors.affiliation: Institute of Molecular Life Sciences (IMLS), University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
authors.forename: Marcella
authors.initials: M
authors.lastname: Kränzlin
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.|Swiss Institute of Bioinformatics (SIB), Quartier Sorge, Bâtiment Génopode, 1015, Lausanne, Switzerland.|Santa Fe Institute (SFI), Santa Fe, NM, 87501, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Wagner
authors.affiliation: Institute of Molecular Life Sciences (IMLS), University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. christian.lehner@imls.uzh.ch.
authors.forename: Christian F
authors.initials: CF
authors.lastname: Lehner
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002453:Cell Cycle / Q000235:genetics; D002470:Cell Survival / Q000235:genetics; D004330:Drosophila / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005298:Fertility / Q000235:genetics; D020440:Gene Duplication; D015870:Gene Expression; D005854:Germ Cells / Q000378:metabolism*; D018386:Kinetochores / Q000378:metabolism*; D008297:Male; D008540:Meiosis; D010802:Phylogeny; D021381:Protein Transport; D012641:Selection, Genetic
chemical_list: D029721:Drosophila Proteins
keywords: Centromere drive; Gene duplication; Kinetochore; Meiosis; Mis12 complex