| 1. |
- Bergman, A., et al.
(författare)
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Rapid identification of pathogenic yeast isolates bt real-time PCR and two-dimensional melting-point analysis
- 2007
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Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer. - 0934-9723 .- 1435-4373. ; 26:11, s. 813-818
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Tidskriftsartikel (refereegranskat)abstract
- There is a need in the clinical microbiological laboratory for rapid and reliable methods for the universal identification of fungal pathogens. Two different regions of the rDNA gene complex, the highly polymorphic ITS1 and ITS2, were amplified using primers targeting conserved regions of the 18S, 5.8S and 28S genes. After melting-point analysis of the amplified products, the Tm of the two PCR-products were plotted into a spot diagram where all the 14 tested, clinically relevant yeasts separated with good resolution. Real-time amplification of two separate genes, melting-point analysis and two-dimensional plotting of Tm data can be used as a broad-range method for the identification of clinical isolates of pathogenic yeast such as Candida and Cryptococcus spp.
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| 2. |
- Bergman, I. M., et al.
(författare)
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A two-nucleotide deletion renders the mannose-binding lectin 2 (MBL2) gene nonfunctional in Danish Landrace and Duroc pigs
- 2014
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Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 66:3, s. 171-184
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Tidskriftsartikel (refereegranskat)abstract
- The mannose-binding lectins (MBLs) are central components of innate immunity, facilitating phagocytosis and inducing the lectin activation pathway of the complement system. Previously, it has been found that certain single-nucleotide polymorphisms (SNPs) in porcine MBL1 and MBL2 (pMBL1, pMBL2) affect mRNA expression, serum concentration, and susceptibility to disease, but the combinatory effect of pMBL1 and pMBL2 genotypes needs further elucidation. In the present study, pMBL1 and pMBL2 alleles, combined pMBL haplotypes, and MBL-A concentration in serum were analyzed in purebred Landrace (N = 30) and Duroc (N = 10) pigs. Furthermore, the combined pMBL haplotypes of 89 PiStrain x (Large White x Landrace) crossbred pigs were studied, and the genotypes of 67 crossbreds challenged with Escherichia coli were compared to their individual disease records. In the purebred animals, three non-synonymous SNPs and a two-nucleotide deletion were detected in the coding sequence of pMBL2. The two-nucleotide deletion was present at a frequency of 0.88 in the Landrace pigs and 0.90 in the Duroc pigs, respectively. In the crossbreds, the T allele of the SNP G949T in pMBL1-previously shown to have profound effect on MBL-A concentration even in the heterozygote condition-was detected in 47 % of the animals. Finally, an association was found between low-producing MBL genotypes and low body weight on the day of weaning in the same animals.
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| 3. |
- Bergman, Ingrid-Maria, 1961-, et al.
(författare)
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European wild boars and domestic pigs display different polymorphic patterns in the Toll-like receptor (TLR) 1, TLR2, and TLR6 genes
- 2010
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Ingår i: Immunogenetics. - : Springer. - 0093-7711 .- 1432-1211. ; 62:1, s. 49-58
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Tidskriftsartikel (refereegranskat)abstract
- During the last decade, the Toll-like receptors (TLRs) have been extensively studied and their immense importance in innate immunity is now being unveiled. Here, we report pronounced differences – probably reflecting the domestication process and differences in selective pressure – between wild boars and domestic pigs regarding single nucleotide polymorphisms (SNPs) in TLR genes. The open reading frames of TLR1, TLR2, and TLR6 were sequenced in 25 wild boars, representing three populations, and in 15 unrelated domestic pigs of Hampshire, Landrace, and Large White origin. In total, 20, 27, and 26 SNPs were detected in TLR1, TLR2, and TLR6, respectively. In TLR1 and TLR2, the numbers of SNPs detected were significantly lower (P ≤ 0.05, P ≤ 0.01) in the wild boars than in the domestic pigs. In the wild boars, one major high frequency haplotype was found in all three genes, while the same pattern was exhibited only by TLR2 in the domestic pigs. The relative frequency of non-synonymous (dN) and synonymous (dS) SNPs was lower for the wild boars than for the domestic pigs in all three genes. In addition, differences in diversity between the genes were revealed: the mean heterozygosity at the polymorphic positions was markedly lower in TLR2 than in TLR1 and TLR6. Because of its localization – in proximity of the bound ligand – one of the non-synonymous SNPs detected in TLR6 may represent species-specific function on the protein level. Furthermore, the codon usage pattern in the genes studied deviated from the general codon usage pattern in Sus scrofa.
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| 4. |
- Bergman, Ingrid-Maria, et al.
(författare)
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European wild boars and domestic pigs display different polymorphic patterns in the Toll-like receptor (TLR)1, TLR2, TLR6, and TLR10 genes.
- 2010
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Ingår i: International Symposium on Animal Genomics for Animal Health Paris, France, 31 May – 2 June 2010. ; , s. 35-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Toll-like receptors (TLR) are vitally important pattern recognition receptors linking innate and adaptive immunity. Several single nucleotide polymorphisms (SNP) in human TLR genes have been associated with disease. There are few studies on associations between polymorphisms in TLR genes and disease in pigs, but the TLR2/TLR6 heterodimer is activated by Mycoplasma hyopneumoniae, and the expression of TLR2, TLR4, and TLR9 is modulated in the presence of different Salmonella serovars. Porcine TLR1, TLR6, and TLR10 are located in a cluster on the p arm of chromosome 8, while TLR2 resides on the q arm. Previously, we identified quantitative trait loci (QTL) for immune-related traits on pig chromosome 8, close to the KIT gene and the microsatellite S0225, respectively. In order to explore polymorphism in some TLR genes in European wild boars and domestic pigs, TLR1, TLR2, and TLR6 were sequenced in 25 wild boars, representing three populations, and in 15 domestic pigs of Hampshire, Landrace, and Large White origin. Similarly, TLR10 was sequenced in 15 wild boars and 15 domestic pigs. In TLR1 and TLR2, more SNP were present in the domestic pigs than in the wild boars. In TLR6, SNP numbers were similar in both animal groups, but the level of heterozygosity was higher in the domestic pigs than in the wild boars. In TLR10, again, more SNP were present in the domestic pigs, and a higher number of nonsynonymous SNP were detected in TLR10 compared to the other genes. This may suggest redundancy for TLR10 in pigs.
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| 5. |
- Bergman, Ingrid-Maria, et al.
(författare)
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Extensive polymorphism in the porcine Toll-like receptor 10 gene
- 2012
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Ingår i: International Journal of Immunogenetics. - 1744-3121 .- 1744-313X. ; 39:1, s. 68-76
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Tidskriftsartikel (refereegranskat)abstract
- The great importance of the Toll-like receptors (TLRs) in innate immunity is well established, but one family member – TLR10 – remains elusive. TLR10 is expressed in various tissues in several species, but its ligand is not known and its function is still poorly understood. The open reading frame of TLR10 was sequenced in 15 wild boars, representing three populations, and in 15 unrelated domestic pigs of Hampshire, Landrace and Large White origin. Amino acid positions corresponding to detected nonsynonymous single nucleotide polymorphisms (SNPs) were analysed in the crystal structures determined for the human TLR1–TLR2–lipopeptide complex and the human TLR10 Toll/Interleukin 1 receptor (TIR) dimer. SNP occurrence in wild boars and domestic pigs was compared, and haplotypes for the TLR10 gene and the TLR6-1-10 gene cluster were reconstructed. Despite the limited number of animals sequenced in the present study (N = 30), a larger number of SNPs were found in TLR10 than recently reported for TLR1, TLR6 and TLR2. Thirty-three SNPs were detected, of which 20 were nonsynonymous. The relative frequency of nonsynonymous (dN) and synonymous (dS) SNPs between wild boars and domestic pigs was higher in TLR10 than recently reported for TLR1, TLR6 and TLR2. However, the polymorphism reported in the present study seems to leave the function of the TLR10 molecule unaffected. Furthermore, no nonsynonymous SNPs were detected in the part of the gene corresponding to the hinge region of the receptor, probably reflecting rigorously acting functional constraint. The total number of SNPs and the number of nonsynonymous SNPs were significantly lower (P < 0.05) in the wild boars than in the domestic pigs, and fewer TLR10 haplotypes were present in the wild boars. The majority of the TLR6-1-10 haplotypes were specific for either wild boars or domestic pigs, probably reflecting differences in microbial environment and population history.
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| 6. |
- Bergman, Ingrid-Maria, 1961-
(författare)
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Polymorphism in pattern recognition receptor genes in pigs
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The mammalian immune defense consists of two systems, which are interconnected and co-operate to provide host defense. The innate immune system is always active and detects and responds to non-self without delay. The adaptive immune system has a lag phase, but is more specific and has got a memory.The innate immune system relies on pattern recognition receptors (PRRs) to detect molecular patterns signaling microbial presence. This thesis focuses on a centrally placed family of PRRs, namely the Toll-like receptors (TLRs), and on mannan-binding lectin (MBL), a PRR which initiates the lectin activation pathway of complement. TLRs are expressed on the cell surface and in intracellular compartments, while MBL is a soluble protein present in most body fluids.Polymorphism – literally ’many forms’ – refers to variation between individuals, at DNA level as well as in traits. A single nucleotide polymorphism (SNP) implicates that alternative nucleotides are present at a particular position in the genome. Mutations, together with phenomena like gene duplication and whole genome duplication, are the ultimate source of variation in nature and the fuel for evolution. Through natural selection and breeding, i.e. artificial selection, species are shaped and change over time.Domestic animals are well suited for genetic studies, since they enable comparisons of populations exposed to different selection criteria and environmental challenges. Also, in the case of pigs, comparisons to the wild ancestor – i.e. the wild boar – can shed light on the evolutionary process. Moreover, pigs are large animal models for humans.Paper I reports the refinement of previously identified quantitative trait loci for immune-related traits on pig chromosome 8.Papers II and III report differences in polymorphic patterns between wild boars and domestic pigs in the TLR1, TLR2, TLR6, and TLR10 genes. In TLR1 and TLR2, more SNPs were present in the domestic pigs than in the wild boars. In TLR6, SNP numbers were similar in both animal groups, but the level of heterozygosity was higher in the domestic pigs than in the wild boars. In TLR10, again, more SNPs were present in the domestic pigs, and a higher number of non-synonymous SNPs was detected in TLR10 compared to the other genes. This might suggest redundancy for TLR10 in pigs.Paper IV reports the presence of an SNP, previously detected in domestic pigs and assumed to affect MBL concentrations in serum, in European wild boars. Also, the connection between the presumed low-producing allele and low MBL concentration in serum was confirmed. Moreover, a novel SNP, with potential to be functionally important, was detected.Owing to the domestication process and differences in selection pressure, differences in polymorphic patterns between wild boars and domestic pigs are not surprising. However, since breeding means choosing among genotypes, the opposite pattern – more SNPs in wild boars than in domestic pigs – would have been expected. However, the result confirms other studies, which have shown that European wild boars went through a bottle neck before domestication started. The higher number of SNPs in domestic pigs may be due to relaxed purifying selection during the domestication process.
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| 7. |
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| 8. |
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| 9. |
- Dahlberg, Anna-Karin, et al.
(författare)
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Hydroxylated and methoxylated polybrominated diphenyl ethers in long-tailed ducks (Clangula hyemalis) and their main food, Baltic blue mussels (Mytilus trossulus x Mytilus edulis)
- 2016
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 144, s. 1475-1483
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Tidskriftsartikel (refereegranskat)abstract
- Long-tailed ducks (Clangula hyemalis) that breed in northern Europe and western Siberia and commonly winter in the Baltic Sea, are threatened by a significant population decrease. The ducks are, by primarily feeding on Baltic blue mussels (Mytilus trossulus x Mytilus edulis) while wintering in the Baltic Sea, potentially subjected to high levels of toxic hydroxylated polybrominated diphenyl ethers (OH-PBDEs). To assess long-tailed ducks exposure to polybrominated phenols (PBPs), polybrominated anisoles (PBAs), hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methylated counterparts (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs), livers of ten long-tailed ducks wintering in the Baltic Sea were analysed. Pattern and levels of analytes in long-tailed ducks (liver) and blue mussels sampled in March and May at nine sites in the Baltic Sea were compared. The geometric mean concentration (ng/g l.w.) in livers of long-tailed ducks and Baltic blue mussels were: ∑2PBPs: 0.57 and 48; ∑2PBAs: 0.83 and 11; ∑7OH-PBDEs: 6.1 and 45; ∑7MeO-PBDEs: 3.8 and 69; ∑7PBDEs: 8.0 and 7.2, respectively. Based on an estimated daily intake of 450 g fresh blue mussel meat, long-tailed ducks daily dietary intake of brominated substances while foraging in the Baltic Sea in March-May was estimated to; 390 ng ∑2PBPs, 90 ng ∑2PBAs, 370 ng ∑7OH-PBDEs, 590 ng ∑7MeO-PBDEs and 59 ng ∑7PBDEs. The low levels of PBPs, PBAs, OH-PBDEs and MeO-PBDEs in the long-tailed duck livers compared to blue mussel, despite a continuous daily intake, suggest that these compounds are poorly retained in long-tailed ducks.
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| 10. |
- Degerholm, Jenny, et al.
(författare)
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Phosphorus-limited growth dynamics in two Baltic Sea cyanobacteria, Nodularia sp and Aphanizomenon sp.
- 2006
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Ingår i: FEMS Microbiology Ecology. - : Oxford University Press (OUP). - 0168-6496 .- 1574-6941. ; 58:3, s. 323-332
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Tidskriftsartikel (refereegranskat)abstract
- Rates of carbon (C) specific growth and nitrogen (N(2)) fixation were monitored in cultures of Baltic Sea Nodularia and Aphanizomenon exposed to gradual limitation by inorganic phosphorus (P). Both cyanobacteria responded by decreased cellular P content followed by lowered rates of growth and N(2) fixation. C-specific growth and cellular N content changed faster in Aphanizomenon both when inorganic P was lowered as well as during reintroduction of P. Aphanizomenon also showed a more rapid increase in N-specific N(2) fixation associated with increased C-specific growth. When ambient concentrations of inorganic P declined, both cyanobacteria displayed higher rates of alkaline phosphatase (APase) activity. Lower substrate half-saturation constants (K(M)) and higher V(max) : K(M) ratio of the APase enzyme associated with Nodularia suggest a higher affinity for dissolved organic P (DOP) substrate than Aphanizomenon. Aphanizomenon, which appears more sensitive to changes in ambient dissolved inorganic P, may be adapted to environments with elevated concentrations of P or repeated intrusions of nutrient-rich water. Nodularia on the other hand, with its higher tolerance to increased P starvation may have an ecological advantage in stratified surface waters of the Baltic Sea during periods of low P availability.
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