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141.
Blood parasites shape extreme major histocompatibility complex diversity in a migratory passerine 下载免费PDF全文
Aleksandra Biedrzycka Wojciech Bielański Adam Ćmiel Wojciech Solarz Tadeusz Zając Magdalena Migalska Alvaro Sebastian Helena Westerdahl Jacek Radwan 《Molecular ecology》2018,27(11):2594-2603
Pathogens are one of the main forces driving the evolution and maintenance of the highly polymorphic genes of the vertebrate major histocompatibility complex (MHC). Although MHC proteins are crucial in pathogen recognition, it is still poorly understood how pathogen‐mediated selection promotes and maintains MHC diversity, and especially so in host species with highly duplicated MHC genes. Sedge warblers (Acrocephalus schoenobaenus) have highly duplicated MHC genes, and using data from high‐throughput MHC genotyping, we were able to investigate to what extent avian malaria parasites explain temporal MHC class I supertype fluctuations in a long‐term study population. We investigated infection status and infection intensities of two different strains of Haemoproteus, that is avian malaria parasites that are known to have significant fitness consequences in sedge warblers. We found that prevalence of avian malaria in carriers of specific MHC class I supertypes was a significant predictor of their frequency changes between years. This finding suggests that avian malaria infections partly drive the temporal fluctuations of the MHC class I supertypes. Furthermore, we found that individuals with a large number of different supertypes had higher resistance to avian malaria, but there was no evidence for an optimal MHC class I diversity. Thus, the two studied malaria parasite strains appear to select for a high MHC class I supertype diversity. Such selection may explain the maintenance of the extremely high number of MHC class I gene copies in sedge warblers and possibly also in other passerines where avian malaria is a common disease. 相似文献
142.
MHC‐mediated sexual selection on birdsong: Generic polymorphism,particular alleles and acoustic signals 下载免费PDF全文
László Zsolt Garamszegi Magdalena Zagalska‐Neubauer David Canal János Török Sándor Zsebők 《Molecular ecology》2018,27(11):2620-2633
Several hypotheses predict that the major histocompatibility complex (MHC) drives mating preference in females. Olfactory, colour or morphological traits are often found as reliable signals of the MHC profile, but the role of avian song mediating MHC‐based female choice remains largely unexplored. We investigated the relationship between several MHC and acoustic features in the collared flycatcher (Ficedula albicollis), a European passerine with complex songs. We screened a fragment of the class IIB second exon of the MHC molecule, of which individuals harbour 4–15 alleles, while considerable sequence diversity is maintained at the population level. To make statistical inferences from a large number of comparisons, we adopted both null‐hypothesis testing and effect size framework in combination with randomization procedures. After controlling for potential confounding factors, neither MHC allelic diversity nor the presence of particular alleles was associated remarkably with the investigated qualitative and quantitative song traits. Furthermore, genetic similarity among males based on MHC sequences was not reflected by the similarity in their song based on syllable content. Overall, these results suggest that the relationship between features of song and the allelic composition and diversity of MHC is not strong in the studied species. However, a biologically motivated analysis revealed that individuals that harbour an MHC allele that impairs survival perform songs with broader frequency range. This finding suggests that certain aspects of the song may bear reliable information concerning the MHC profile of the individuals, which can be used by females to optimize mate choice. 相似文献
143.
Tibor Janda Radwan Khalil Judit Tajti Magda Pál Gabriella Szalai Szabolcs Rudnóy Ilona Rácz György Kátay Anna B. Molnár Magdalena A. Lejmel Tihana Marček Gyöngyvér Gell Zsófia Birinyi Éva Darko 《Plant Growth Regulation》2018,85(2):305-315
High salinity is one of the major environmental factors limiting the productivity of crop species worldwide. Improving the stress tolerance of cultivated plants and thus increasing crop yields in an environmentally friendly way is a crucial task in agriculture. In the present work the ability of a new derivative, S-methylmethionine-salicylate (MMS), to improve the salt tolerance of wheat plants was tested parallel with its related compounds salicylic acid and S-methylmethionine. The results show that while these compounds are harmful at relatively high concentration (0.5 mM), they may provide protection against high salinity at lower (0.1 mM) concentration. This was confirmed by gas exchange, chlorophyll content and chlorophyll-a fluorescence induction measurements. While osmotic adjustment probably plays a critical role in the improved salt tolerance, neither Na or K transport from the roots to the shoots nor proline synthesis are the main factors in the tolerance induced by the compounds tested. MMS, S-methylmethionine and Na-salicylate had different effects on flavonol biosynthesis. It was also shown that salt treatment had a substantial influence on the SA metabolism in wheat roots and leaves. Present results suggest that the investigated compounds can be used to improve salt tolerance in plants. 相似文献
144.
Magdalena Wąsik Katarzyna Nazimek Krzysztof Bryniarski 《Microbiology and immunology》2018,62(8):485-496
145.
Magdalena Mazur-Kuśnirek Zofia Antoszkiewicz Krzysztof Lipiński Joanna Kaliniewicz Sylwia Kotlarczyk Przemysław Żukowski 《Archives of animal nutrition》2019,73(2):111-126
The aim of this study was to determine the effect of a polyphenol product (PP) (Proviox) and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature. The experimental materials comprised 120 ROSS 308 broilers (6 treatments, 10 replications, 2 birds per replication). Dietary supplementation with vitamin E and PP was applied in the following experimental design: group I (negative control) – without supplementation; group II (positive control) – without supplementation; group III – supplementation with 100 mg vitamin E/kg; group IV – 200 mg vitamin E/kg; group V – 100 mg vitamin E/kg and 100 mg PP/kg; group VI – 200 mg PP/kg. In groups II–VI, broiler chickens aged 21–35 d were exposed to increased temperature (34°C for 10 h daily). In chickens exposed to high temperature, dietary supplementation with antioxidants, mostly PP, improved growth performance parameters, including body weight, body weight gain and feed intake until 28 d of age. Vitamin E added to broiler chicken diets at 200 mg/kg and vitamin E combined with PP was most effective in improving the total antioxidant status of birds, enhancing blood antioxidant enzyme activities and increasing vitamin E concentrations in the liver and breast muscles. Broilers fed diets supplemented with 200 mg/kg of vitamin E alone and vitamin E in combination with PP were characterised by a higher percentage content of breast muscles in the carcass. Dietary supplementation with antioxidants improved the water-holding capacity of meat, reduced natural drip loss and increased the crude ash content of meat. The breast muscles of chickens fed diets supplemented with PP had a lower contribution of yellowness. The breast muscles of chickens receiving diets with 100 mg vitamin E/kg(group III) and diets supplemented with PP (groups V and VI) were characterised by the highest concentrations of polyunsaturated fatty acids. The PP can be a valuable component of diets for broiler chickens exposed to high temperature. 相似文献
146.
Magdalena Polak-Berecka Adam Waśko Roman Paduch Tomasz Skrzypek Anna Sroka-Bartnicka 《Antonie van Leeuwenhoek》2014,106(4):751-762
The aim of this study was to analyze the cell envelope components and surface properties of two phenotypes of Lactobacillus rhamnosus isolated from the human gastrointestinal tract. The ability of the bacteria to adhere to human intestinal cells and to aggregate with other bacteria was determined. L. rhamnosus strains E/N and PEN differed with regard to the presence of exopolysaccharides (EPS) and specific surface proteins. Transmission electron microscopy showed differences in the structure of the outer cell surface of the strains tested. Bacterial surface properties were analyzed by Fourier transform infrared spectroscopy, fatty acid methyl esters and hydrophobicity assays. Aggregation capacity and adhesion of the tested strains to the human colon adenocarcinoma cell line HT29 was determined. The results indicated a high adhesion and aggregation ability of L. rhamnosus PEN, which possessed specific surface proteins, had a unique fatty acid content, and did not synthesize EPS. Adherence of L. rhamnosus was dependent on specific interactions and was promoted by surface proteins (42–114 kDa) and specific fatty acids. Polysaccharides likely hindered bacterial adhesion and aggregation by masking protein receptors. This study provides information on the cell envelope constituents of lactobacilli that influence bacterial aggregation and adhesion to intestinal cells. This knowledge will help to understand better their specific contribution in commensal–host interactions and adaptation to this ecological niche. 相似文献
147.
Lidia Ostanek Magdalena Ostanek-Pańka Danuta Bobrowska-Snarska Agnieszka Bińczak-Kuleta Katarzyna Fischer Mariusz Kaczmarczyk Andrzej Ciechanowicz Marek Brzosko 《Molecular biology reports》2014,41(9):6195-6200
To assess the association between PTPN22 1858C>T gene polymorphism and susceptibility to, and clinical presentation of, systemic lupus erythematosus (SLE). Our study included 135 SLE patients (120 women and 15 men; mean age 45.1 years; mean course of disease from 0.5 to 31 years) and 201 healthy subjects. The PTPN22 1858C>T gene polymorphism was genotyped by polymerase chain reaction restriction fragment length polymorphism. A significantly higher incidence of genotype CT in patients with SLE (36.3 %) was found, compared with the control group (24.9 %). The frequencies of C1858 and T1858 alleles were 78.1 and 21.9 % in SLE patients and 86.1 and 13.9 % in controls, respectively. Significantly higher SLE susceptibility was observed in patients carrying at least one T allele (p = 0.009; OR 1.86; 95 % CI 0.14–3.05). Significant association of the PTPN22 T1858 allele (CT + TT vs.CC) and secondary antiphospholipid syndrome was observed (p = 0.049). In SLE patients carrying the T1858 allele, higher levels of antiphospholipid antibodies (anticardiolipin antibodies and/or lupus anticoagulant) were found (p = 0.030; OR 2.17; 95 % CI 1.07–4.44). 相似文献
148.
The effect of experimental exposure to low doses of zearalenone on uterine histology and morphometry in prepubertal bitches 总被引:1,自引:0,他引:1
The experiment involved 30 clinically healthy prepubertal bitches aged approximately 70 days with an estimated initial body weight (BW) of 8 kg. The animals were randomly divided into two experimental groups (EI and EII) and a control group of 10 animals each. Group EI was administered 50 μg zearalenone (ZEN)/kg BW per os for 42 days, group EII received 75 μg zearalenone/kg BW per os for 42 days, and the control group was administered placebo per os for 42 days. The bitches were hysterectomized at the end of treatment, and samples of uterine tissue were collected for histological and morphometric analyses. The results of the study indicate that exposure to very low doses of ZEN (100% and 150% of the NOAEL) causes simple glandular hyperplasia of the endometrium accompanied by adenogenesis, angiogenesis, and vasodilatation with the related consequences. The noted changes were more pronounced in group EI and less visible in group EII in comparison with group C, which could be indicative of a hormetic dose response. 相似文献
149.
Ewa Maciaszczyk-Dziubinska Magdalena MigockaDonata Wawrzycka Katarzyna MarkowskaRobert Wysocki 《生物化学与生物物理学报:生物膜》2014
The yeast transporter Acr3p is a low affinity As(III)/H+ and Sb(III)/H+ antiporter located in the plasma membrane. It has been shown for bacterial Acr3 proteins that just a single cysteine residue, which is located in the middle of the fourth transmembrane region and conserved in all members of the Acr3 family, is essential for As(III) transport activity. Here, we report a systematic mutational analysis of all nine cysteine residues present in the Saccharomyces cerevisiae Acr3p. We found that mutagenesis of highly conserved Cys151 resulted in a complete loss of metalloid transport function. In addition, lack of Cys90 and Cys169, which are conserved in eukaryotic members of Acr3 family, impaired Acr3p trafficking to the plasma membrane and greatly reduced As(III) efflux, respectively. Mutagenesis of five other cysteines in Acr3p resulted in moderate reduction of As(III) transport capacities and sorting perturbations. Our data suggest that interaction of As(III) with multiple thiol groups in the yeast Acr3p may facilitate As(III) translocation across the plasma membrane. 相似文献
150.
Liliana Surmacz Danuta Plochocka Magdalena Kania Witold Danikiewicz Ewa Swiezewska 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2014,1841(2):240-250
cis-Prenyltransferases (CPTs) comprise numerous enzymes synthesizing isoprenoid hydrocarbon skeleton with isoprenoid units in the cis (Z) configuration. The chain-length specificity of a particular plant CPT is in most cases unknown despite the composition of the accumulated isoprenoids in the tissue of interest being well established. In this report AtCPT6, one of the nine Arabidopsis thaliana CPTs, is shown to catalyze the synthesis of a family of very short-chain polyisoprenoid alcohols of six, seven, and eight isoprenoid units, those of seven units dominating. The product specificity of AtCPT6 was established in vivo following its expression in the heterologous system of the yeast Saccharomyces cerevisiae and was confirmed by the absence of specific products in AtCPT6 T-DNA insertion mutants and their overaccumulation in AtCPT6-overexpressing plants. These observations are additionally validated in silico using an AtCPT6 model obtained by homology modeling. AtCPT6 only partially complements the function of the yeast homologue of CPT-Rer2 since it restores the growth but not protein glycosylation in rer2Δ yeast. This is the first in planta characterization of specific products of a plant CPT producing polyisoprenoids. Their distribution suggests that a joint activity of several CPTs is required to produce the complex mixture of polyisoprenoid alcohols found in Arabidopsis roots. 相似文献