title: Clinal variation at phenology-related genes in spruce: parallel evolution in FTL2 and Gigantea?
abstract: Parallel clines in different species, or in different geographical regions of the same species, are an important source of information on the genetic basis of local adaptation. We recently detected latitudinal clines in SNPs frequencies and gene expression of candidate genes for growth cessation in Scandinavian populations of Norway spruce (Picea abies). Here we test whether the same clines are also present in Siberian spruce (P. obovata), a close relative of Norway spruce with a different Quaternary history. We sequenced nine candidate genes and 27 control loci and genotyped 14 SSR loci in six populations of P. obovata located along the Yenisei river from latitude 56°N to latitude 67°N. In contrast to Scandinavian Norway spruce that both departs from the standard neutral model (SNM) and shows a clear population structure, Siberian spruce populations along the Yenisei do not depart from the SNM and are genetically unstructured. Nonetheless, as in Norway spruce, growth cessation is significantly clinal. Polymorphisms in photoperiodic (FTL2) and circadian clock (Gigantea, GI, PRR3) genes also show significant clinal variation and/or evidence of local selection. In GI, one of the variants is the same as in Norway spruce. Finally, a strong cline in gene expression is observed for FTL2, but not for GI. These results, together with recent physiological studies, confirm the key role played by FTL2 and circadian clock genes in the control of growth cessation in spruce species and suggest the presence of parallel adaptation in these two species.
authors.affiliation: Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, 75236 Uppsala, Sweden.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, 75236 Uppsala, Sweden.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tsuda
authors.affiliation: Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, 75236 Uppsala, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Stocks
authors.affiliation: Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, 75236 Uppsala, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Källman
authors.affiliation: Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, 75236 Uppsala, Sweden.
authors.forename: Nannan
authors.initials: N
authors.lastname: Xu
authors.affiliation: Finnish Forest Research Institute, 900014, Finland.
authors.forename: Katri
authors.initials: K
authors.lastname: Kärkkäinen
authors.affiliation: Finnish Forest Research Institute, 900014, Finland.
authors.forename: Tea
authors.initials: T
authors.lastname: Huotari
authors.affiliation: Institute of Plant and Animal Ecology, Urals Division of the Russian Academy of Sciences, 620144 Ekaterinburg, Russia.
authors.forename: Vladimir L
authors.initials: VL
authors.lastname: Semerikov
authors.affiliation: Consiglio Nazionale delle Ricerche, Institute of Biosciences and Bioresources, 50019 Sesto Fiorentino, Firenze, Italy.
authors.forename: Giovanni G
authors.initials: GG
authors.lastname: Vendramin
authors.affiliation: Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life Laboratory, Uppsala University, 75236 Uppsala, Sweden martin.lascoux@ebc.uu.se.
authors.forename: Martin
authors.initials: M
authors.lastname: Lascoux
mesh_terms: D001499:Bayes Theorem; D016000:Cluster Analysis; D003198:Computer Simulation; D003710:Demography; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D005787:Gene Frequency / Q000235:genetics; D017343:Genes, Plant; D056426:Genetic Loci; D005828:Genetics, Population; D005843:Geography; D016014:Linear Models; D015810:Linkage Disequilibrium / Q000235:genetics; D009711:Nucleotides / Q000235:genetics; D028222:Picea / Q000235:genetics* / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012800:Siberia
chemical_list: D009711:Nucleotides; D010940:Plant Proteins
keywords: FTL2; Gigantea; clinal variation; parallel evolution; spruce