| 1. |
- Dahlbom, Josefin, et al.
(författare)
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Boldness predicts social status in zebrafish (Danio rerio)
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:8
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Tidskriftsartikel (refereegranskat)abstract
- This study explored if boldness could be used to predict social status. First, boldness was assessed by monitoring individual zebrafish behaviour in (1) an unfamiliar barren environment with no shelter (open field), (2) the same environment when a roof was introduced as a shelter, and (3) when the roof was removed and an unfamiliar object (Lego® brick) was introduced. Next, after a resting period of minimum one week, social status of the fish was determined in a dyadic contest and dominant/subordinate individuals were determined as the winner/loser of two consecutive contests. Multivariate data analyses showed that males were bolder than females and that the behaviours expressed by the fish during the boldness tests could be used to predict which fish would later become dominant and subordinate in the ensuing dyadic contest. We conclude that bold behaviour is positively correlated to dominance in zebrafish and that boldness is not solely a consequence of social dominance.
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| 2. |
- Lagman, David, et al.
(författare)
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Expansion of transducin subunit gene families in early vertebrate tetraploidizations
- 2012
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Ingår i: Genomics. - : Elsevier BV. - 0888-7543 .- 1089-8646. ; 100:4, s. 203-211
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Tidskriftsartikel (refereegranskat)abstract
- Hundreds of gene families expanded in the early vertebrate tetraploidizations including many gene families in the phototransduction cascade. We have investigated the evolution of the heterotrimeric G-proteins of photoreceptors, the transducins, in relation to these events using both phylogenetic analyses and synteny comparisons. Three alpha subunit genes were identified in amniotes and the coelacanth, GNAT1-3; two of these were identified in amphibians and teleost fish, GNAT1 and GNAT2. Most tetrapods have four beta genes, GNB1-4, and teleosts have additional duplicates. Finally, three gamma genes were identified in mammals, GNGT1, GNG11 and GNGT2. Of these, GNGT1 and GNGT2 were found in the other vertebrates. In frog and zebrafish additional duplicates of GNGT2 were identified. Our analyses show all three transducin families expanded during the early vertebrate tetraploidizations and the beta and gamma families gained additional copies in the teleost-specific genome duplication. This suggests that the tetraploidizations contributed to visual specialisations.
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| 3. |
- Lagman, David, et al.
(författare)
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The vertebrate ancestral repertoire of visual opsins, transducin alpha subunits and oxytocin/vasopressin receptors was established by duplication of their shared genomic region in the two rounds of early vertebrate genome duplications
- 2013
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 13, s. 238-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Vertebrate color vision is dependent on four major color opsin subtypes: RH2 (green opsin), SWS1 (ultraviolet opsin), SWS2 (blue opsin), and LWS (red opsin). Together with the dim-light receptor rhodopsin (RH1), these form the family of vertebrate visual opsins. Vertebrate genomes contain many multi-membered gene families that can largely be explained by the two rounds of whole genome duplication (WGD) in the vertebrate ancestor (2R) followed by a third round in the teleost ancestor (3R). Related chromosome regions resulting from WGD or block duplications are said to form a paralogon. We describe here a paralogon containing the genes for visual opsins, the G-protein alpha subunit families for transducin (GNAT) and adenylyl cyclase inhibition (GNAI), the oxytocin and vasopressin receptors (OT/VP-R), and the L-type voltage-gated calcium channels (CACNA1-L). Results: Sequence-based phylogenies and analyses of conserved synteny show that the above-mentioned gene families, and many neighboring gene families, expanded in the early vertebrate WGDs. This allows us to deduce the following evolutionary scenario: The vertebrate ancestor had a chromosome containing the genes for two visual opsins, one GNAT, one GNAI, two OT/VP-Rs and one CACNA1-L gene. This chromosome was quadrupled in 2R. Subsequent gene losses resulted in a set of five visual opsin genes, three GNAT and GNAI genes, six OT/VP-R genes and four CACNA1-L genes. These regions were duplicated again in 3R resulting in additional teleost genes for some of the families. Major chromosomal rearrangements have taken place in the teleost genomes. By comparison with the corresponding chromosomal regions in the spotted gar, which diverged prior to 3R, we could time these rearrangements to post-3R. Conclusions: We present an extensive analysis of the paralogon housing the visual opsin, GNAT and GNAI, OT/VP-R, and CACNA1-L gene families. The combined data imply that the early vertebrate WGD events contributed to the evolution of vision and the other neuronal and neuroendocrine functions exerted by the proteins encoded by these gene families. In pouched lamprey all five visual opsin genes have previously been identified, suggesting that lampreys diverged from the jawed vertebrates after 2R.
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| 4. |
- Larhammar, Dan, et al.
(författare)
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Turtle ghrelin
- 2014
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 46:6, s. 524-525
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Tidskriftsartikel (refereegranskat)
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