title: Characterization and Expression of the Zebrafish qki Paralogs.
abstract: Quaking (QKI) is an RNA-binding protein involved in post-transcriptional mRNA processing. This gene is found to be associated with several human neurological disorders. Early expression of QKI proteins in the developing mouse neuroepithelium, together with neural tube defects in Qk mouse mutants, suggest the functional requirement of Qk for the establishment of the nervous system. As a knockout of Qk is embryonic lethal in mice, other model systems like the zebrafish could serve as a tool to study the developmental functions of qki. In the present study we sought to characterize the evolutionary relationship and spatiotemporal expression of qkia, qki2, and qkib; zebrafish homologs of human QKI. We found that qkia is an ancestral paralog of the single tetrapod Qk gene that was likely lost during the fin-to-limb transition. Conversely, qkib and qki2 are orthologs, emerging at the root of the vertebrate and teleost lineage, respectively. Both qki2 and qkib, but not qkia, were expressed in the progenitor domains of the central nervous system, similar to expression of the single gene in mice. Despite having partially overlapping expression domains, each gene has a unique expression pattern, suggesting that these genes have undergone subfunctionalization following duplication. Therefore, we suggest the zebrafish could be used to study the separate functions of qki genes during embryonic development.
authors.affiliation: Department of Evolution and Development, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
authors.forename: Katarzyna J
authors.initials: KJ
authors.lastname: Radomska
authors.affiliation: Department of Evolution and Development, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Sager
authors.affiliation: Department of Evolution and Development, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
authors.forename: Bryn
authors.initials: B
authors.lastname: Farnsworth
authors.affiliation: Department of Evolution and Development, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
authors.forename: Åsa
authors.initials: Å
authors.lastname: Tellgren-Roth
authors.affiliation: Department of Evolution and Development, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
authors.forename: Giulia
authors.initials: G
authors.lastname: Tuveri
authors.affiliation: Department of Neuroscience, Uppsala Biomedical Centre, Uppsala University, Uppsala, Sweden.
authors.forename: Christiane
authors.initials: C
authors.lastname: Peuckert
authors.affiliation: Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|Department of Neuropathology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom.
authors.forename: Petronella
authors.initials: P
authors.lastname: Kettunen
authors.affiliation: Department of Evolution and Development, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
authors.forename: Elena
authors.initials: E
authors.lastname: Jazin
authors.affiliation: Department of Evolution and Development, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
authors.forename: Lina S
authors.initials: LS
authors.lastname: Emilsson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D043344:Chordata / Q000033:anatomy & histology / Q000235:genetics; D017124:Conserved Sequence; D019143:Evolution, Molecular; D005121:Extremities / Q000196:embryology; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics; D009420:Nervous System / Q000196:embryology / Q000378:metabolism; D054259:Neural Tube / Q000378:metabolism; D010802:Phylogeny; D016601:RNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D017385:Sequence Homology; D013045:Species Specificity; D026801:Synteny; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; D029961:Zebrafish Proteins; C490831:qk protein, zebrafish