| 1. |
- Warren, Wesley C, et al.
(författare)
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The genome of a songbird
- 2010
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 464:7289, s. 757-762
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Tidskriftsartikel (refereegranskat)abstract
- The zebra finch is an important model organism in several fields with unique relevance to human neuroscience. Like other songbirds, the zebra finch communicates through learned vocalizations, an ability otherwise documented only in humans and a few other animals and lacking in the chicken-the only bird with a sequenced genome until now. Here we present a structural, functional and comparative analysis of the genome sequence of the zebra finch (Taeniopygia guttata), which is a songbird belonging to the large avian order Passeriformes. We find that the overall structures of the genomes are similar in zebra finch and chicken, but they differ in many intrachromosomal rearrangements, lineage-specific gene family expansions, the number of long-terminal-repeat-based retrotransposons, and mechanisms of sex chromosome dosage compensation. We show that song behaviour engages gene regulatory networks in the zebra finch brain, altering the expression of long non-coding RNAs, microRNAs, transcription factors and their targets. We also show evidence for rapid molecular evolution in the songbird lineage of genes that are regulated during song experience. These results indicate an active involvement of the genome in neural processes underlying vocal communication and identify potential genetic substrates for the evolution and regulation of this behaviour.
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| 2. |
- Künstner, Axel, et al.
(författare)
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Comparative genomics based on massive parallel transcriptome sequencing reveals patterns of substitution and selection across 10 bird species
- 2010
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 19:Suppl.1, s. 266-276
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Tidskriftsartikel (refereegranskat)abstract
- Next-generation sequencing technology provides an attractive means to obtain largescale sequence data necessary for comparative genomic analysis. To analyse the patterns of mutation rate variation and selection intensity across the avian genome, we performed brain transcriptome sequencing using Roche 454 technology of 10 different non-model avian species. Contigs from de novo assemblies were aligned to the two available avian reference genomes, chicken and zebra finch. In total, we identified 6499 different genes across all 10 species, with ∼1000 genes found in each full run per species. We found evidence for a higher mutation rate of the Z chromosome than of autosomes (male-biased mutation) and a negative correlation between the neutral substitution rate (dS) and chromosome size. Analyses of the mean dN/dS ratio (ω) of genes across chromosomes supported the Hill-Robertson effect (the effect of selection at linked loci) and point at stochastic problems with x as an independent measure of selection. Overall, this study demonstrates the usefulness of next-generation sequencing for obtaining genomic resources for comparative genomic analysis of non-model organisms.
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| 3. |
- Nabholz, Benoit, et al.
(författare)
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Obtaining mtDNA genomes from next-generation transcriptome sequencing : A case study on the basal Passerida (Aves: Passeriformes) phylogeny
- 2010
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 57:1, s. 466-470
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Tidskriftsartikel (refereegranskat)abstract
- Classically, the mitochondrial genome is sequenced by a series of amplicons using conserved PCR primers. Here we show how shot-gun transcriptome sequencing can be used to obtain the complete set of protein-coding genes from the mtDNA of four passerine bird species. With these sequences, we address the still unresolved basal Passerida relationships (Ayes: Passeriformes). Our analysis suggests a new hypothesis for the basal relationships of Passerida, namely a clade grouping Sylvioidea and Passeroidea, with Paridae and Muscicapidae as successive sister groups to this clade. This study demonstrates the usefulness of next-generation sequencing transcriptome sequencing for obtaining new mtDNA genomes.
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| 4. |
- Zapka, Manuela, et al.
(författare)
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Night-time neuronal activation of Cluster N in a day- and night-migrating songbird
- 2010
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Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 32:4, s. 619-624
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Tidskriftsartikel (refereegranskat)abstract
- Magnetic compass orientation in a night-migratory songbird requires that Cluster N, a cluster of forebrain regions, is functional. Cluster N, which receives input from the eyes via the thalamofugal pathway, shows high neuronal activity in night-migrants performing magnetic compass-guided behaviour at night, whereas no activation is observed during the day, and covering up the birds' eyes strongly reduces neuronal activation. These findings suggest that Cluster N processes light-dependent magnetic compass information in night-migrating songbirds. The aim of this study was to test if Cluster N is active during daytime migration. We used behavioural molecular mapping based on ZENK activation to investigate if Cluster N is active in the meadow pipit (Anthus pratensis), a day- and night-migratory species. We found that Cluster N of meadow pipits shows high neuronal activity under dim-light at night, but not under full room-light conditions during the day. These data suggest that, in day- and night-migratory meadow pipits, the light-dependent magnetic compass, which requires an active Cluster N, may only be used during night-time, whereas another magnetosensory mechanism and/or other reference system(s), like the sun or polarized light, may be used as primary orientation cues during the day.
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