| 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. |
- Clayton, Geoffrey C., et al.
(författare)
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THE CIRCUMSTELLAR ENVIRONMENT OF R CORONAE BOREALIS : WHITE DWARF MERGER OR FINAL-HELIUM-SHELL FLASH?
- 2011
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 743:1, s. 44-
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Tidskriftsartikel (refereegranskat)abstract
- In 2007, R Coronae Borealis (R CrB) went into a historically deep and long decline. In this state, the dust acts like a natural coronagraph at visible wavelengths, allowing faint nebulosity around the star to be seen. Imaging has been obtained from 0.5 to 500 mu m with Gemini/GMOS, Hubble Space Telescope/WFPC2, Spitzer/MIPS, and Herschel/SPIRE. Several of the structures around R CrB are cometary globules caused by wind from the star streaming past dense blobs. The estimated dust mass of the knots is consistent with their being responsible for the R CrB declines if they form along the line of sight to the star. In addition, there is a large diffuse shell extending up to 4 pc away from the star containing cool 25 K dust that is detected all the way out to 500 mu m. The spectral energy distribution of R CrB can be well fitted by a 150 AU disk surrounded by a very large diffuse envelope which corresponds to the size of the observed nebulosity. The total masses of the disk and envelope are 10(-4) and 2M(circle dot), respectively, assuming a gas-to-dust ratio of 100. The evidence pointing toward a white dwarf merger or a final-helium-shell flash origin for R CrB is contradictory. The shell and the cometary knots are consistent with a fossil planetary nebula. Along with the fact that R CrB shows significant lithium in its atmosphere, this supports the final-helium-shell flash. However, the relatively high inferred mass of R CrB and its high fluorine abundance support a white dwarf merger.
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| 3. |
- Anderson, Beverley H., et al.
(författare)
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Mutations in CTC1, encoding conserved telomere maintenance component 1, cause Coats plus
- 2012
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 44:3, s. 338-342
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Tidskriftsartikel (refereegranskat)abstract
- Coats plus is a highly pleiotropic disorder particularly affecting the eye, brain, bone and gastrointestinal tract. Here, we show that Coats plus results from mutations in CTC1, encoding conserved telomere maintenance component 1, a member of the mammalian homolog of the yeast heterotrimeric CST telomeric capping complex. Consistent with the observation of shortened telomeres in an Arabidopsis CTC1 mutant and the phenotypic overlap of Coats plus with the telomeric maintenance disorders comprising dyskeratosis congenita, we observed shortened telomeres in three individuals with Coats plus and an increase in spontaneous gamma H2AX-positive cells in cell lines derived from two affected individuals. CTC1 is also a subunit of the alpha-accessory factor (AAF) complex, stimulating the activity of DNA polymerase-alpha primase, the only enzyme known to initiate DNA replication in eukaryotic cells. Thus, CTC1 may have a function in DNA metabolism that is necessary for but not specific to telomeric integrity.
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| 4. |
- Zhang, Guojie, et al.
(författare)
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Comparative genomics reveals insights into avian genome evolution and adaptation
- 2014
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 346:6215, s. 1311-1320
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Tidskriftsartikel (refereegranskat)abstract
- Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific erosion of repetitive elements, large segmental deletions, and gene loss. Avian genomes furthermore show a remarkably high degree of evolutionary stasis at the levels of nucleotide sequence, gene synteny, and chromosomal structure. Despite this pattern of conservation, we detected many non-neutral evolutionary changes in protein-coding genes and noncoding regions. These analyses reveal that pan-avian genomic diversity covaries with adaptations to different lifestyles and convergent evolution of traits.
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| 5. |
- Flavin, Richard, et al.
(författare)
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SPINK1 protein expression and prostate cancer progression
- 2014
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Ingår i: Clinical Cancer Research. - Philadelphia, USA : American Association for Cancer Research. - 1078-0432 .- 1557-3265. ; 20:18, s. 4904-11
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: SPINK1 overexpression has been described in prostate cancer and is linked with poor prognosis in many cancers. The objective of this study was to characterize the association between SPINK1 overexpression and prostate cancer-specific survival.Experimental design: The study included 879 participants in the U.S. Physicians' Health Study and Health Professionals Follow-Up Study, diagnosed with prostate cancer (1983-2004) and treated by radical prostatectomy. Protein tumor expression of SPINK1 was evaluated by immunohistochemistry on tumor tissue microarrays.Results: Seventy-four of 879 (8%) prostate cancer tumors were SPINK1 positive. Immunohistochemical data were available for PTEN, p-Akt, pS6, stathmin, androgen receptor (AR), and ERG (as a measure of the TMPRSS2:ERG translocation). Compared with SPINK1-negative tumors, SPINK1-positive tumors showed higher PTEN and stathmin expression, and lower expression of AR (P < 0.01). SPINK1 overexpression was seen in 47 of 427 (11%) ERG-negative samples and in 19 of 427 (4%) ERG-positive cases (P = 0.0003). We found no significant associations between SPINK1 status and Gleason grade or tumor stage. There was no association between SPINK1 expression and biochemical recurrence (P = 0.56). Moreover, there was no association between SPINK1 expression and prostate cancer mortality (there were 75 lethal cases of prostate cancer during a mean of 13.5 years follow-up; HR = 0.71; 95% confidence interval, 0.29-1.76).Conclusions: Our results suggest that SPINK1 protein expression may not be a predictor of recurrence or lethal prostate cancer amongst men treated by radical prostatectomy. SPINK1 and ERG protein expression do not seem to be entirely mutually exclusive, as some previous studies have suggested.
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