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1.
Helicobacter pylori (H. pylori) can convert to coccoid form in unfavorable conditions or as a result of antibiotic treatment. In order to adapt to harsh environments, H. pylori requires a stringent response which, encoded by the spoT gene, has a bifunctional enzyme possessing both (p)ppGpp synthetic and degrading activity. Our goal in this study was to compare spoT gene expression in spiral and induced coccoid forms of H. pylori with use of amoxicillin. First, clinical isolate coccoid forms were induced with amoxicillin; then, the viability test was analyzed by flow cytometer. After RNA extraction, cDNA synthesis and designing a specific primer for spoT gene, evaluation of the desired gene expression in both forms were studied. Bacterial isolates exposed to amoxicillin at MIC and 1/2 MIC induced morphological conversion better and faster than other MIC concentration. The expression of spoT gene was significantly downregulated in spiral forms of H. pylori, while the gene expression was upregulated and + 30.3-fold changes was seen in coccoid forms of bacterium. To summarize, spoT gene is one of the key factors for antibiotic resistance and its enhanced expression in coccoid form can be a valuable diagnostic marker for recognition of H. pylori during morphological conversion.  相似文献   

2.
In addition to the already known cagA gene, novel genetic markers have been associated with Helicobacter pylori (H. pylori) virulence: the dupA and vacAi genes. These genes might play an important role as specific markers to determine the clinical outcome of the disease, especially the vacAi gene, which has been expected to be a good marker of severe pathologies like gastric adenocarcinoma. In the present study, the association of cagA, dupA, and vacAi genes with gastroduodenal pathologies in Chilean patients was studied. One hundred and thirty-two patients positive for H. pylori were divided into two groups—non-severe and severe gastric pathologies—and investigated for the presence of cagA, dupA, and vacAi H. pylori virulence genes by PCR. The cagA gene was detected in 20/132 patients (15.2%), the vacAi1 gene was detected in 54/132 patients (40.9%), the vacAi2 gene was detected in 26/132 patients (19.7%), and the dupA gene was detected in 50/132 (37.9%) patients. Logistic regression model analysis showed that the vacAi1 isoform gene in the infected strains and the severity of the diseases outcome were highly associated, causing severe gastric damage that may lead to gastric cancer (p < 0.0001; OR = 8.75; 95% CI 3.54–21.64). Conversely, cagA (p = 0.3507; OR = 1.62; 95% CI 0.59–4.45) and vacAi2 (p = 0.0114; OR = 3.09; 95% CI 1.26–7.60) genes were not associated with damage, while the dupA gene was associated significantly with non-severe clinical outcome (p = 0.0032; OR = 0.25; 95% CI 0.09–0.65). In addition, dupA gene exerts protection against severe gastric pathologies induced by vacAi1 by delaying the outcome of the disease by approximately 20 years.  相似文献   

3.
Some Bacillus species, especially Bacillus subtilis and Bacillus pumilus groups, have highly similar 16S rRNA gene sequences, which are hard to identify based on 16S rDNA sequence analysis. To conquer this drawback, rpoB, recA sequence analysis along with randomly amplified polymorphic (RAPD) fingerprinting was examined as an alternative method for differentiating Bacillus species. The 16S rRNA, rpoB and recA genes were amplified via a polymerase chain reaction using their specific primers. The resulted PCR amplicons were sequenced, and phylogenetic analysis was employed by MEGA 6 software. Identification based on 16S rRNA gene sequencing was underpinned by rpoB and recA gene sequencing as well as RAPD-PCR technique. Subsequently, concatenation and phylogenetic analysis showed that extent of diversity and similarity were better obtained by rpoB and recA primers, which are also reinforced by RAPD-PCR methods. However, in one case, these approaches failed to identify one isolate, which in combination with the phenotypical method offsets this issue. Overall, RAPD fingerprinting, rpoB and recA along with concatenated genes sequence analysis discriminated closely related Bacillus species, which highlights the significance of the multigenic method in more precisely distinguishing Bacillus strains. This research emphasizes the benefit of RAPD fingerprinting, rpoB and recA sequence analysis superior to 16S rRNA gene sequence analysis for suitable and effective identification of Bacillus species as recommended for probiotic products.  相似文献   

4.
A complex study on the adaptation of cn and vn mutants and the allozymes of alcoholdehydrogenase (ADH) was carried out in initially pure lines, and their panmixia populations during exchange of the mutant genotype with that of wild-type flies (C-S) and D) through saturating crossings. The relative adaptation of the genotypes was estimated by their effect on reproductive efficiency in the experimentally obtained population. Fecundity, lifespan, and the resistance of the studied genotypes to hyperthermia were investigated individually. It was shown that the high level of adaptation of the cn mutants and the low level of adaptation of the vg mutants was correlated with the presence of different ADH allozymes. In the studied population, the F-allozyme of ADH accompanied the vg mutation, while the S-allozyme of the enzyme was detected in cn mutants. Saturating crossings of C-S(Adh Svg(Adh F) and D(Adh F) × cn(Adh S), along with the parallel determination of the allele composition of the Adh locus, demonstrated that the complete substitution of the F-allozyme of ADH in the vg mutants by the S-allozyme in D flies, as well as the substitution of the S-allozyme of ADH in the cn mutants by the F-allozyme in D flies was realized only after the 15th–20th backcrosses. These results favor the coadaptation of cn and vg marker genes with alleles of the Adh locus and indicate the important role of the latter in the adaptation of genotypes. In the studied population, selection acted primarily against the vg mutants, which were inferior to the cn mutants, and heterozygote genotypes in indices of the main adaptation components.  相似文献   

5.
As observed in other self-incompatible species in the Pyrinae subtribe, loquat (Eriobotrya japonica) demonstrates gametophytic self-incompatibility that is controlled by the S-locus, which encodes a polymorphic stylar ribonuclease (S-RNase). This allows the female reproductive organ (style) to recognize and reject the pollen from individuals with the same S-alleles, but allows the pollen from individuals with different S-alleles to effect fertilization. The S-genotype is therefore an important consideration in breeding strategies and orchard management. In an attempt to optimize the selection of parental lines in loquat production, the S-RNase alleles of 35 loquat cultivars and their 26 progeny, as well as five wild loquat species, were identified and characterized in this study. The best pollinizer cultivar combinations were also explored. A total of 28 S-alleles were detected, 21 of which constituted novel S-RNase alleles. The S-haplotypes S2 and S6 were the most frequent, followed by S 29 , S 31 , S 5 , S 24 , S 28 , S 33 , S 34 , S 32 , and S 15 , while the rare alleles S 1 , S 9 , S 14 , S 16 , S 17 , S 18 , S 19 , S 20 , S 21 , S 22 , S 23 , S 27 , and S 35 were only observed in one of the accessions tested. Moreover, the S-genotypes of five wild loquat species (E. prinoides, E. bengalensis, E. prinoides var. dadunensis, E. deflexa, and E. japonica) are reported here for the first time. The results will not only facilitate the selection of suitable pollinators for optimal orchard management, but could also encourage the crossbreeding of wild loquat species to enhance the genetic diversity of loquat cultivars.  相似文献   

6.
Radish, belonging to the family Brassicaceae, has a self-incompatibility which is controlled by multiple alleles on the S locus. To employ the self-incompatibility in an F1 breeding system, identification of S haplotypes is necessary. Since collection of S haplotypes and determination of nucleotide sequences of SLG, SRK, and SCR alleles in cultivated radish have been conducted by different groups independently, the same or similar sequences with different S haplotype names and different sequences with the same S haplotype names have been registered in public databases, resulting in confusion of S haplotype names for researchers and breeders. In the present study, we developed S homozygous lines from radish F1 hybrid cultivars in Japan and determined the nucleotide sequences of SCR, the S domain and the kinase domain of SRK, and the SLG of a large number of S haplotypes. Comparing these sequences with our previously published sequences, the haplotypes were ordered into 23 different S haplotypes. The sequences of the 23 S haplotypes were compared with S haplotype sequences registered by different groups, and we suggested a unification of these S haplotypes. Furthermore, dot-blot hybridization using SRK allele-specific probes was examined for developing a standard method for S haplotype identification.  相似文献   

7.

Key message

Map-based cloning identified a candidate gene for resistance to the anthracnose fungal pathogen Colletotrichum orbiculare in cucumber, which reveals a novel function for the highly conserved STAYGREEN family genes for host disease resistance in plants.

Abstract

Colletotrichum orbiculare is a hemibiotrophic fungal pathogen that causes anthracnose disease in cucumber and other cucurbit crops. No host resistance genes against the anthracnose pathogens have been cloned in crop plants. Here, we reported fine mapping and cloning of a resistance gene to the race 1 anthracnose pathogen in cucumber inbred lines Gy14 and WI 2757. Phenotypic and QTL analysis in multiple populations revealed that a single recessive gene, cla, was underlying anthracnose resistance in both lines, but WI2757 carried an additional minor-effect QTL. Fine mapping using 150 Gy14?×?9930 recombinant inbred lines and 1043 F2 individuals delimited the cla locus into a 32 kb region in cucumber Chromosome 5 with three predicted genes. Multiple lines of evidence suggested that the cucumber STAYGREEN (CsSGR) gene is a candidate for the anthracnose resistance locus. A single nucleotide mutation in the third exon of CsSGR resulted in the substitution of Glutamine in 9930 to Arginine in Gy14 in CsSGR protein which seems responsible for the differential anthracnose inoculation responses between Gy14 and 9930. Quantitative real-time PCR analysis indicated that CsSGR was significantly upregulated upon anthracnose pathogen inoculation in the susceptible 9930, while its expression was much lower in the resistant Gy14. Investigation of allelic diversities in natural cucumber populations revealed that the resistance allele in almost all improved cultivars or breeding lines of the U.S. origin was derived from PI 197087. This work reveals an unknown function for the highly conserved STAYGREEN (SGR) family genes for host disease resistance in plants.
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8.
We aimed to study MLH1 and MGMT methylation status in Helicobacter pylori-associated chronic gastritis in Egyptian patients with and without gastric cancer. 39 patients were included in our study. They were divided into 2 groups; patients without (group I) and with gastric adenocarcinoma (group II). Patients were subjected to clinical examination, abdominal ultrasound and upper endoscopy for gastric biopsy. Biopsies were subjected to urease test, histological examination, and DNA purification. H. pylori, Braf, Kras, MLH1 and MGMT methylation were assessed by quantitative PCR. DNA sequencing was performed to assess Braf and Kras genes mutation. qPCR of H. pylori was significantly higher in patients with adenocarcinoma (group II) than those without adenocarcinoma (group I); with a p < 0.001 as well as in patients with age above 50 years with a p value = 0.008. By applying logistic regression analysis it was reported that the H. pylori qPCR is a significant predictor to the adenocarcinoma with OR = 1.025 (95 % CI: 1. 002–1.048), with sensitivity of 90 % and specificity of 100 %. Adenocarcinoma patients had a significantly higher mean age and levels of H. Pylori, Braf, K-ras, methylated MGMT and methylated MLH1 than those of gastritis patients. DNA sequence analysis of Braf (codon 12) and Kras (codon 600) had genes mutation in gastric adenocarcinoma versus chronic gastritis. Conclusion: H. pylori may cause epigenetic changes predisposing the patients to cancer stomach. Estimation of H. pylori by qPCR can be a good predictor to adenocarcinoma. Braf and Kras genes mutation were reveled in gastritis and adenocarcinoma patients.  相似文献   

9.

Key message

A novel powdery mildew-resistance gene, designated Pm58, was introgressed directly from Aegilops tauschii to hexaploid wheat, mapped to chromosome 2DS, and confirmed to be effective under field conditions. Selectable KASP? markers were developed for MAS.

Abstract

Powdery mildew caused by Blumeria graminis (DC.) f. sp. tritici (Bgt) remains a significant threat to wheat (Triticum aestivum L.) production. The rapid breakdown of race-specific resistance to Bgt reinforces the need to identify novel sources of resistance. The d-genome species, Aegilops tauschii, is an excellent source of disease resistance that is transferrable to T. aestivum. The powdery mildew-resistant Ae. tauschii accession TA1662 (2n?=?2x?=?DD) was crossed directly with the susceptible hard white wheat line KS05HW14 (2n?=?6x?=?AABBDD) followed by backcrossing to develop a population of 96 BC2F4 introgression lines (ILs). Genotyping-by-sequencing was used to develop a genome-wide genetic map that was anchored to the Ae. tauschii reference genome. A detached-leaf Bgt assay was used to screen BC2F4:6 ILs, and resistance was found to segregate as a single locus (χ?=?2.0, P value?=?0.157). The resistance gene, referred to as Pm58, mapped to chromosome 2DS. Pm58 was evaluated under field conditions in replicated trials in 2015 and 2016. In both years, a single QTL spanning the Pm58 locus was identified that reduced powdery mildew severity and explained 21% of field variation (P value?<?0.01). KASP? assays were developed from closely linked GBS-SNP markers, a refined genetic map was developed, and four markers that cosegregate with Pm58 were identified. This novel source of powdery mildew-resistance and closely linked genetic markers will support efforts to develop wheat varieties with powdery mildew resistance.
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10.

Key message

An NB-LRR gene, TYNBS1, was isolated from Begomovirus-resistance locus Ty-2. Transgenic plant analysis revealed that TYNBS1 is a functional resistance gene. TYNBS1 is considered to be synonymous with Ty-2.

Abstract

Tomato yellow leaf curl disease caused by Tomato yellow leaf curl virus (TYLCV) is a serious threat to tomato (Solanum lycopersicum L.) production worldwide. A Begomovirus resistance gene, Ty-2, was introduced into cultivated tomato from Solanum habrochaites by interspecific crossing. To identify the Ty-2 gene, we performed genetic analysis. Identification of recombinant line 3701 confirmed the occurrence of a chromosome inversion in the Ty-2 region of the resistant haplotype. Genetic analysis revealed that the Ty-2 gene is linked to an introgression encompassing two markers, SL11_25_54277 and repeat A (approximately 200 kb). Genomic sequences of the upper and lower border of the inversion section of susceptible and resistant haplotypes were determined. Two nucleotide-binding domain and leucine-rich repeat-containing (NB-LRR) genes, TYNBS1 and TYNBS2, were identified around the upper and lower ends of the inversion section, respectively. TYNBS1 strictly co-segregated with TYLCV resistance, whereas TYNBS2 did not. Genetic introduction of genomic fragments containing the TYNBS1 gene into susceptible tomato plants conferred TYLCV resistance. These results demonstrate that TYNBS1 is a functional resistance gene for TYLCV, and is synonymous with the Ty-2 gene.
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11.
Multiple susceptibility genes (S), identified in Arabidopsis, have been shown to be functionally conserved in crop plants. Mutations in these S genes result in resistance to different pathogens, opening a new way to achieve plant disease resistance. The aim of this study was to investigate the role of Defense No Death 1 (DND1) in susceptibility of tomato and potato to late blight (Phytophthora infestans). In Arabidopsis, the dnd1 mutant has broad-spectrum resistance against several fungal, bacterial, and viral pathogens. However this mutation is also associated with a dwarfed phenotype. Using an RNAi approach, we silenced AtDND1 orthologs in potato and tomato. Our results showed that silencing of the DND1 ortholog in both crops resulted in resistance to the pathogenic oomycete P. infestans and to two powdery mildew species, Oidium neolycopersici and Golovinomyces orontii. The resistance to P. infestans in potato was effective to four different isolates although the level of resistance (complete or partial) was dependent on the aggressiveness of the isolate. In tomato, DND1-silenced plants showed a severe dwarf phenotype and autonecrosis, whereas DND1-silenced potato plants were not dwarfed and showed a less pronounced autonecrosis. Our results indicate that S gene function of DND1 is conserved in tomato and potato. We discuss the possibilities of using RNAi silencing or loss-of-function mutations of DND1 orthologs, as well as additional S gene orthologs from Arabidopsis, to breed for resistance to pathogens in crop plants.  相似文献   

12.
Pathogenicity of Candida albicans is associated with its capacity switch from yeast-like to hyphal growth. The hyphal form is capable to penetrate the epithelial surfaces and to damage the host tissues. Therefore, many investigations have focused on mechanisms that control the morphological transitions of C. albicans. Recently, certain studies have showed that non-albicans Candida species can reduce the capacity of C. albicans to form biofilms and to develop candidiasis in animal models. Then, the objective of this study was to evaluate the effects of Candida krusei and Candida glabrata on the morphogenesis of C. albicans. Firstly, the capacity of reference and clinical strains of C. albicans in forming hyphae was tested in vitro. After that, the expression of HWP1 (hyphal wall protein 1) gene was determined by quantitative real-time PCR (polymerase chain reaction) assay. For both reference and clinical strains, a significant inhibition of the hyphae formation was observed when C. albicans was incubated in the presence of C. krusei or C. glabrata compared to the control group composed only by C. albicans. In addition, the culture mixed of C. albicans-C. krusei or C. albicans-C. glabrata reduced significantly the expression of HWP1 gene of C. albicans in relation to single cultures of this specie. In both filamentation and gene expression assays, C. krusei showed the higher inhibitory activity on the morphogenesis of C. albicans compared to C. glabrata. C. krusei and C. glabrata are capable to reduce the filamentation of C. albicans and consequently decrease the expression of the HWP1 gene.  相似文献   

13.
The association of the variable rs1801282 locus of the PPARG2 gene (peroxisome proliferator-activated receptor gamma) with type 2 diabetes mellitus and its complications was analyzed in inhabitants of the Republic of Bashkortostan. The genotype frequencies of the variable rs1801282 locus of the PPARG2 gene did not significantly differ in groups of healthy persons and patients with type 2 diabetes in all three considered inheritance models (codominant, dominant, and recessive). At the same time, it was demonstrated that the risk of one of the diabetic complications, i.e., diabetic nephropathy, was associated with the variable rs1801282 locus of the PPARG2 gene. Diabetic nephropathy was more common in patients with the C/C genotype (62.7%) compared to the C/G and G/G genotypes (37.5%), P = 0.036. The G allele is protective in regard to diabetic nephropathy (OR = 0.36) in patients with type 2 diabetes mellitus.  相似文献   

14.
15.
The study was aimed to analyze the relation between individual genotypes and allelic variants of SNPs g.2141C>G of growth hormone gene, g.914T>A and g.257A>G of growth hormone receptor gene with growth and reproduction traits and to evaluate the populationgenetic structure in Aberdeen-Angus cattle (Bos taurus L., 1758) sample of Eastern Ukraine according SNPs studied. Allele C of SNP g.2141C>G has a positive correlation with birth weight, body stature, bigger rump, udder and total exterior evaluation score, shorter calving interval and better calve birth weight and negative correlation with calve average daily gain. Allele T of SNP g.914T>A has positive correlation with the muscle and udder size; live weight in each age, average daily gain, weight and average daily gain of calves born conform to the principle AA>TTTA. SNP g.257A>G showed a positive correlation for G allele with muscle size. The population is in equilibrium for SNPs g.2141C>G and g.257A>G, and in disequilibrium for SNP g.914T>A. The analysis showed no linkage disequilibrium between SNPs g.914T>A and g.257A>G. Inbreeding coefficient FST in Aberdeen-Angus group studied was 16.1%.  相似文献   

16.
Using bioinformatics analysis, the homologs of genes Sr33 and Sr35 were identified in the genomes of Triticum aestivum, Hordeum vulgare, and Triticum urartu. It is known that these genes confer resistance to highly virulent wheat stem rust races (Ug99). To identify amino acid sites important for this resistance, the found homologs were compared with the Sr33 and Sr35 protein sequences. It was found that sequences S5DMA6 and E9P785 are the closest homologs of protein RGAle, a Sr33 gene product, and sequences M7YFA9 (CNL-C) and F2E9R2 are homologs of protein CNL9, a Sr35 gene product. It is assumed that the homologs of genes Sr33 and Sr35, which were obtained from the wild relatives of wheat and barley, can confer resistance to various forms of stem rust and can be used in the future breeding programs aimed at improvement of national wheat varieties.  相似文献   

17.
Helicobacter (H.) pylori infection is an important risk factor for gastric cancer that causes gastric inflammation. Inflammatory chemokines such as interleukin (IL)-8 and regulated on activation normal T cell expressed and secreted (RANTES) are elevated in the gastric mucosa by H. pylori. This study aimed to investigate the effects of Lactobacillus paracasei strain 06TCa19, a probiotic strain, on IL-8 and RANTES expression and production induced by H. pylori using human gastric epithelial cell lines. Strain 06TCa19 was shown to suppress H. pylori-mediated elevation of gene expression related to these chemokines in MKN45 cells. The strain also suppressed the increase in IL-8 and RANTES products induced by H. pylori in AGS cells as well as in MKN45 cells. In MKN45 cells inoculated with H. pylori, strain 06TCa19 was shown to downregulate the activation of NF-κB and p38 MAPK signaling pathways. Additionally, the level of the CagA virulence protein of H. pylori in the MKN45 cells and the number of viable H. pylori adhering to MKN45 cells decreased with the addition of strain 06TCa19. Moreover, the strain 06TCa19 notably increased lactic acid in the supernatant of MKN45 cells. Thus, lactic acid released from strain 06TCa19 might have inhibited the adhesion of H. pylori to MKN45 cells and prevented the insertion of H. pylori CagA into the cells, and elevation of IL-8 and RANTES genes and proteins might be suppressed by downregulating the NF-κB and p38 MAPK pathways. Therefore, use of strain 06TCa19 may prevent H. pylori-associated gastric inflammation.  相似文献   

18.
The present study was designed to characterize phenotypically and genotypically a Trueperella pyogenes strain isolated from a brain abscess of an adult roebuck (Capreolus capreolus). The species identity could be confirmed by phenotypical investigations, by MALDI-TOF MS analysis, and by sequencing the 16S ribosomal RNA (rRNA) gene, the 16S–23S rRNA intergenic spacer region (ISR); by sequencing the target genes rpoB, gap, and tuf; and by detection of T. pyogenes chaperonin-encoding gene cpn60 with a previously developed loop-mediated isothermal amplification (LAMP) assay. The T. pyogenes strain could additionally be characterized by PCR-mediated amplification of several known and putative virulence factor-encoding genes which revealed the presence of the genes plo encoding pyolysin and nanH and nanP encoding neuraminidases; the genes fimA, fimC, and fimE encoding the fimbrial subunits FimA, FimC, and FimE; and the gene cbpA encoding collagen-binding protein CbpA. The present data give a detailed characterization of a T. pyogenes strain isolated from a brain abscess of a roebuck. However, the route of infection of the roebuck remains unclear.  相似文献   

19.
Polyploid Prunus spinosa (2n = 4×) and P. insititia (2n = 6×) represent enormous genetic potential in Central Europe, which can be exploited in breeding programmes. In Hungary, 17 cultivar candidates were selected from wild-growing populations including 10 P. spinosa, 4 P. insititia and three P. spinosa × P. domestica hybrids (2n = 5×). Their taxonomic classification was based on their phenotypic characteristics. Six simple sequence repeats (SSRs) and the multiallelic S-locus genotyping were used to characterize genetic variability and reliable identification of the tested accessions. A total of 98 SSR alleles were identified, which presents 19.5 average allele number per locus, and each of the 17 genotypes could be discriminated based on unique SSR fingerprints. A total of 23 S-RNase alleles were identified. The complete and partial S-genotype was determined for 8 and 9 accessions, respectively. The identification of a cross-incompatible pair of cultivar candidates and several semi-compatible combinations help maximize fruit set in commercial orchards. Our results indicate that the S-allele pools of wild-growing P. spinosa and P. insititia are overlapping in Hungary. A phylogenetic and principal component analysis confirmed the high level of diversity and genetic differentiation present within the analysed genotypes and helped clarify doubtful taxonomic identities. Our data confirm that S-locus genotyping is suitable for diversity studies in polyploid Prunus species. The analysed accessions represent huge genetic potential that can be exploited in commercial cultivation.  相似文献   

20.
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