| 1. |
- Dorshorst, Ben, et al.
(författare)
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A Complex Genomic Rearrangement Involving the Endothelin 3 Locus Causes Dermal Hyperpigmentation in the Chicken
- 2011
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Ingår i: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 7:12, s. e1002412-
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Tidskriftsartikel (refereegranskat)abstract
- Dermal hyperpigmentation or Fibromelanosis (FM) is one of the few examples of skin pigmentation phenotypes in the chicken, where most other pigmentation variants influence feather color and patterning. The Silkie chicken is the most widespread and well-studied breed displaying this phenotype. The presence of the dominant FM allele results in extensive pigmentation of the dermal layer of skin and the majority of internal connective tissue. Here we identify the causal mutation of FM as an inverted duplication and junction of two genomic regions separated by more than 400 kb in wild-type individuals. One of these duplicated regions contains endothelin 3 (EDN3), a gene with a known role in promoting melanoblast proliferation. We show that EDN3 expression is increased in the developing Silkie embryo during the time in which melanoblasts are migrating, and elevated levels of expression are maintained in the adult skin tissue. We have examined four different chicken breeds from both Asia and Europe displaying dermal hyperpigmentation and conclude that the same structural variant underlies this phenotype in all chicken breeds. This complex genomic rearrangement causing a specific monogenic trait in the chicken illustrates how novel mutations with major phenotypic effects have been reused during breed formation in domestic animals.
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| 2. |
- Ek, Weronica, et al.
(författare)
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Genetic analysis of metabolic traits in an intercross between body weight-selected chicken lines
- 2010
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Ingår i: Physiological Genomics. - : American Physiological Society. - 1094-8341 .- 1531-2267. ; 42:1, s. 20-22
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Tidskriftsartikel (refereegranskat)abstract
- A network of four interacting loci has been reported previously to influence growth in two lines of chickens divergently selected for body weight at 56 days of age. Located on chromosomes 3 (Growth4), 4 (Growth6), 7 (Growth9), and 20 (Growth12), they explained nearly half of the difference in body weight at selection age between the two lines. The original study reported effects on body weight and fat deposition, but no attempts were made to explore the effects of the network on other phenotypes measured in the F(2) population. In this study we conducted further analyses to evaluate the specific effects of the four-locus network on other metabolic traits as well as refining results from the original study by including a larger number of genetic markers in the quantitative trait locus (QTL) regions. We confirm the previously described effect of the epistatic network on body weight and show that the network increases the total amount of muscle and fat as well as the weight of the internal organs. The network as a whole did not change the relative content of any studied organs or tissues in the body. There was, however, a significant interaction between the loci on chromosomes 3 and 7 that changed the relative proportion of abdominal fat and breast muscle in the chicken by increasing abdominal fat weight without a corresponding increase in muscle mass.
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| 3. |
- Englund, Thomas, et al.
(författare)
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Relatedness and diversity of nine Swedish local chicken breeds as indicated by the mtDNA D-loop
- 2014
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 151, s. 229-233
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Tidskriftsartikel (refereegranskat)abstract
- In this study part of the mitochondrial D-loop was sequenced in a total of 40 samples from nine Swedish local chicken breeds. Among our 40 samples we observed 15 segregating sites and seven different haplotypes. The most common haplotype was present in all investigated individuals in fi ve breeds and together with other haplotypes in three breeds. This haplotype is common in domestic chickens and has been found in both local and commercial breeds in many parts of the world. The breed Ö landsh ö na was most different from the other Swedish breeds with all three individuals sharing a haplotype that differed from the most common haplotype at nine of the 15 segregating sites.
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| 4. |
- Eriksson, Jonas, et al.
(författare)
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Identification of the yellow skin gene reveals a hybrid origin of the domestic chicken
- 2008
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Ingår i: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 4:2, s. e1000010-
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Tidskriftsartikel (refereegranskat)abstract
- Yellow skin is an abundant phenotype among domestic chickens and is caused by a recessive allele (W*Y) that allows deposition of yellow carotenoids in the skin. Here we show that yellow skin is caused by one or more cis-acting and tissue-specific regulatory mutation(s) that inhibit expression of BCDO2 (beta-carotene dioxygenase 2) in skin. Our data imply that carotenoids are taken up from the circulation in both genotypes but are degraded by BCDO2 in skin from animals carrying the white skin allele (W*W). Surprisingly, our results demonstrate that yellow skin does not originate from the red junglefowl (Gallus gallus), the presumed sole wild ancestor of the domestic chicken, but most likely from the closely related grey junglefowl (Gallus sonneratii). This is the first conclusive evidence for a hybrid origin of the domestic chicken, and it has important implications for our views of the domestication process.
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| 5. |
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| 6. |
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| 7. |
- Ka, Sojeong, 1976-, et al.
(författare)
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Extremely Different Behaviours in High and Low Body Weight Lines of Chicken are Associated with Differential Expression of Genes Involved in Neuronal Plasticity
- 2009
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Ingår i: Journal of neuroendocrinology (Print). - : Wiley. - 0953-8194 .- 1365-2826 .- 0022-0795 .- 1479-6805. ; 21:3, s. 208-216
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Tidskriftsartikel (refereegranskat)abstract
- Long-term selection (> 45 generations) for low or high body weight from the same founder population has generated two extremely divergent lines of chickens, the low (LWS) and high weight (HWS) lines, which at the age of selection (56 days) differs by more than nine-fold in body weight. The HWS line chickens are compulsive feeders, whereas, in the LWS line, some individuals are anorexic and others have very low appetites. The involvement of the central nervous system in these behavioural differences has been experimentally supported. We compared a brain region at 0 and 56 days of age containing the major metabolic regulatory regions, including the hypothalamus and brainstem, using a global cDNA array expression analysis. The results obtained show that the long-term selection has produced minor but multiple expression differences. Genes that regulate neuronal plasticity, such as actin filament polymerisation and brain-derived neurotrophic factor, were identified as being differentially expressed. Genes involved in lipid metabolism were over-represented among differentially expressed genes. The expression data confirm that neural systems regulating feeding behaviours in these lines are different. The results suggest that the lines are set in separate developmental trajectories equipped with slightly different nervous systems. We suggest that the lines adapt behaviourally different to changing situations post hatch, such as the transition from dependence on yolk to feeding, in order to obtain energy. The present study has identified and exemplifies the kind of changes that may underlie the extreme differences in such behaviours.
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| 8. |
- Malekkhaiat Häffner, Sara, et al.
(författare)
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Interaction of Laponite with Membrane Components - Consequences for Bacterial Aggregation and Infection Confinement
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 11:17, s. 15389-15400
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Tidskriftsartikel (refereegranskat)abstract
- The antimicrobial effects of Laponite nanoparticles with or without loading of the antimicrobial peptide LL-37 was investigated along with their membrane interactions. The study combines data from ellipsometry, circular dichroism, fluorescence spectroscopy, particle size/ζ potential measurements, and confocal microscopy. As a result of the net negative charge of Laponite, loading of net positively charged LL-37 increases with increasing pH. The peptide was found to bind primarily to the outer surface of the Laponite nanoparticles in a predominantly helical conformation, leading to charge reversal. Despite their net positive charge, peptide-loaded Laponite nanoparticles did not kill Gram-negative Escherichia coli bacteria or disrupt anionic model liposomes. They did however cause bacteria flocculation, originating from the interaction of Laponite and bacterial lipopolysaccharide (LPS). Free LL-37, in contrast, is potently antimicrobial through membrane disruption but does not induce bacterial aggregation in the concentration range investigated. Through LL-37 loading of Laponite nanoparticles, the combined effects of bacterial flocculation and membrane lysis are observed. However, bacteria aggregation seems to be limited to Gram-negative bacteria as Laponite did not cause flocculation of Gram-positive Bacillus subtilis bacteria nor did it bind to lipoteichoic acid from bacterial envelopes. Taken together, the present investigation reports several novel phenomena by demonstrating that nanoparticle charge does not invariably control membrane destabilization and by identifying the ability of anionic Laponite nanoparticles to effectively flocculate Gram-negative bacteria through LPS binding. As demonstrated in cell experiments, such aggregation results in diminished LPS-induced cell activation, thus outlining a promising approach for confinement of infection and inflammation caused by such pathogens.
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| 9. |
- Malekkhaiat Häffner, Sara, et al.
(författare)
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Nanoclay-induced bacterial flocculation for infection confinement
- 2020
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 562, s. 71-80
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Tidskriftsartikel (refereegranskat)abstract
- Effects of size and charge of anionic nanoclays on their interactions with bacteria-mimicking lipid membranes, bacterial lipopolysaccharide (LPS), and Gram-negative bacteria were investigated using ellipsometry, dynamic light scattering, ζ-potential measurements, and confocal microscopy combined with Live/Dead staining. Based on particle size and charge density, three different anionic hectorite nanoclays were employed, and investigated in the presence and absence of the net cationic human antimicrobial peptide LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES). In the absence of this peptide, the nanoclays were found not to bind to similarly anionic bacteria-mimicking model phospholipid membranes, nor to destabilize these. Similarly, while all nanoclays induced aggregation of Escherichia coli bacteria, the flocculated bacteria remained alive after aggregation. In contrast, LL-37 alone, i.e. in the absence of nanoclay particles, displays antimicrobial properties through membrane lysis, but does not cause bacterial aggregation in the concentration range investigated. After loading the nanoclays with LL-37, potent bacterial aggregation combined with bacterial membrane lysis was observed for all nanoclay sizes and charge densities. Demonstrating the potential of these combined systems for confinement of infection, LPS-induced NF-κB activation in human monocytes was found to be strongly suppressed after nanoclay-mediated aggregation, with a wide tolerance for nanoparticle size and charge density.
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| 10. |
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