| 1. |
- Lehtonen, PK, et al.
(author)
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Candidate genes for colour and vision exhibit signals of selection across the pied flycatcher (Ficedula hypoleuca) breeding range
- 2012
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In: Heredity. - : Springer Science and Business Media LLC. - 1365-2540 .- 0018-067X. ; 108:4, s. 431-440
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Journal article (peer-reviewed)abstract
- The role of natural selection in shaping adaptive trait differentiation in natural populations has long been recognized. Determining its molecular basis, however, remains a challenge. Here, we search for signals of selection in candidate genes for colour and its perception in a passerine bird. Pied flycatcher plumage varies geographically in both its structural and pigment-based properties. Both characteristics appear to be shaped by selection. A single-locus outlier test revealed 2 of 14 loci to show significantly elevated signals of divergence. The first of these, the follistatin gene, is expressed in the developing feather bud and is found in pathways with genes that determine the structure of feathers and may thus be important in generating variation in structural colouration. The second is a gene potentially underlying the ability to detect this variation: SWS1 opsin. These two loci were most differentiated in two Spanish pied flycatcher populations, which are also among the populations that have the highest UV reflectance. The follistatin and SWS1 opsin genes thus provide strong candidates for future investigations on the molecular basis of adaptively significant traits and their co-evolution.
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| 2. |
- Saarikangas, J, et al.
(author)
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Missing-in-metastasis MIM/MTSS1 promotes actin assembly at intercellular junctions and is required for integrity of kidney epithelia
- 2011
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In: Journal of cell science. - : The Company of Biologists. - 1477-9137 .- 0021-9533. ; 124:8Pt 8, s. 1245-1255
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Journal article (peer-reviewed)abstract
- MIM/MTSS1 is a tissue-specific regulator of plasma membrane dynamics, whose altered expression levels have been linked to cancer metastasis. MIM deforms phosphoinositide-rich membranes through its I-BAR domain and interacts with actin monomers through its WH2 domain. Recent work proposed that MIM also potentiates Sonic hedgehog (Shh)-induced gene expression. Here, we generated MIM mutant mice and found that full-length MIM protein is dispensable for embryonic development. However, MIM-deficient mice displayed a severe urinary concentration defect caused by compromised integrity of kidney epithelia intercellular junctions, which led to bone abnormalities and end-stage renal failure. In cultured kidney epithelial (MDCK) cells, MIM displayed dynamic localization to adherens junctions, where it promoted Arp2/3-mediated actin filament assembly. This activity was dependent on the ability of MIM to interact with both membranes and actin monomers. Furthermore, results from the mouse model and cell culture experiments suggest that full-length MIM is not crucial for Shh signaling, at least during embryogenesis. Collectively, these data demonstrate that MIM modulates interplay between the actin cytoskeleton and plasma membrane to promote the maintenance of intercellular contacts in kidney epithelia.
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