scholarly journals Genetic polymorphism of ToxB+ Pyrenophora tritici-repentis strains

2021 ◽  
Vol 19 (2) ◽  
pp. 121-129
Author(s):  
Nina V. Mironenko ◽  
Aleksandra S. Orina ◽  
Nadezhda M. Kovalenko
Keyword(s):  
Copy Number ◽  
Low Frequency ◽  
Original Strain ◽  
Division Rate ◽  
Wheat Varieties ◽  
Additional Function ◽  
Average Copy Number ◽  
Pyrenophora Tritici Repentis ◽  
Leaf Chlorosis ◽  
Average Copy

BACKGROUND: The phytotoxin Ptr ToxB as well as Ptr ToxA is one of the pathogenic factors of Pyrenophora tritici-repentis, that cause leaf chlorosis on susceptible wheat varieties, and is encoded by ToxB gene. P. tritici-repentis strains with ToxB gene are rather rare worldwide. MATERIALS AND METHODS: The object of the study was 37 strains isolated from the leaves of wheat grown in Greece. The virulence of the strains was analyzed and the presence of effector genes as well as the average copy number of ToxB was determined. RESULTS: The race composition of P. tritici-repentis population turned out to be mainly represented by the avirulent race 4 (50% of the strains). Strains of race 1 were not found, while strains of other races were found with a low frequency in the population. All analyzed P. tritici-repentis strains had ToxB gene in the genome, while its homologues and ToxA gene were not detected. The average copy number (R) of ToxB in three P. tritici-repentis strains varied from 0.24 to 1.22. The average copy number of ToxB in the mitotic generation of P. tritici-repentis Gr8 strain, which was characterized by the lowest value of R = 0.24, varied from 0.01 to 0.74 and, on average, turned out to be 2 times higher than in the original strain Gr8. CONCLUSION: Presumably, P. tritici-repentis has a mechanism that gives ToxB+ nuclei an advantage in the division rate over ToxB nuclei. This mechanism indicates the existence of an additional function of this gene that is not associated with pathogenicity.

Array CGH Analysis for PTCL-U Revealed Two Genetically Distinct Subgroups.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2054-2054
Author(s):  
Masao Nakagawa ◽  
Aya Oshiro ◽  
Hiroyuki Tagawa ◽  
Sivasundaram Karnan ◽  
Shinobu Tsuzuki ◽  
...  
Keyword(s):  
T Cell ◽  
Comparative Genomic Hybridization ◽  
Copy Number ◽  
Array Cgh ◽  
Comparative Genomic ◽  
Simple Type ◽  
Genomic Hybridization ◽  
Complex Type ◽  
Average Copy Number ◽  
Average Copy

Abstract Peripheral T-cell lymphoma, unspecified (PTCL-U) is the most common group among Peripheral T-cell lymphomas (PTCLs). This category consists of the cases which do not belong to any of the recognizable subtypes of PTCLs in WHO classification. PTCL-U comprises heterogeneous groups in morphology and phenotype. Molecular basis of clinical heterogeneity is needed to identify distinct subgroups with clnical relevance. Several reports of conventional cytogenetic studies including comparative genomic hybridization (CGH) showed some recurrent aberrations, but failed to identify the genetic hallmarks to categorize distinct subgroups. So far, no array-based comparative genomic hybridization (array CGH) study for PTCL-U has been reported. Here we analyzed 29 cases of PTCL-U by means of array CGH consisting of 2265 artificial chromosome clones that cover the whole genome at a 1.3 mega base resolution. The analysis clearly divided these cases into two distinct subgroups on the basis of frequency of genomic alterations. One group consists of 17 cases which showed significant lower copy number changes (average copy number gains: 0.5 regions, average copy number losses: 0.1 regions). The other group had average copy number gains of 15.7 regions and losses of 15.0 regions in 12 cases. We designate the former as “simple type” and the latter as “complex type”. In the complex type, regions of recurrent (>20%) gain are detected on chromosome 1q23.3-24.2, 3q25.31-tel, 4p15.1-16.1, 4q28.3-31.23, 5q34, 6p24.1-25.1, 7p21.3-tel, 7p21.1, 7q, 8q24.23, 11q13.4-tel, 12p11.21-11.22, 16p12.3-13.3, 17q11.2-22. Regions of recurrent (>20%) losses are detected on chromosome 1p13.1-13.3, 2q37.3, 4q21.21-21.23, 4q34.3-35.1, 5q21.2-23.1, 6p12.1-q14.3, 6q23.2-24.1, 6q25.1-26, 7p14.3-22.1, 9p21.3, 10p14-qtel, 12p13.1-13.2, 13, 14q12, 16q, 17p, 18p, 20q13-2, 22q11.21-12.2. Median age is 62 years in the simple type and 73 years in the complex type, respectively. Median survival is 27 months in the simple type and 11 months in the complex type. Log-rank test for overall survival between the simple type and the complex type showed inferior survival for the complex type but significance was marginal (p=0.21). Our findings showed that PTCL-U comprised two genetically distinct subgroups, implying that distinct mechanisms underlay in molecular pathogenesis of PTCL-U. Furthermore cilinicopathological features of each group are also being studied.

scholarly journals Fast and accurate average genome size and 16S rRNA gene average copy number computation in metagenomic data

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Emiliano Pereira-Flores ◽  
Frank Oliver Glöckner ◽  
Antonio Fernandez-Guerra
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Genome Size ◽  
Copy Number ◽  
Metagenomic Data ◽  
Rrna Gene ◽  
Average Copy Number ◽  
Average Copy

scholarly journals Viability of pathogenic dermatophytes during a 4-week treatment with 1% topical luliconazole for tinea pedis

2019 ◽  
Vol 58 (3) ◽  
pp. 401-403 ◽  
Author(s):  
Tomoyuki Iwanaga ◽  
Tsuyoshi Ushigami ◽  
Kazushi Anzawa ◽  
Takashi Mochizuki
Keyword(s):  
Ribosomal Rna ◽  
Internal Transcribed Spacer ◽  
Copy Number ◽  
Tinea Pedis ◽  
Pathogenic Fungi ◽  
Topical Administration ◽  
Initial Visit ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Average Copy

Abstract The viability of pathogenic fungi in the scale was investigated during topical administration of 1% luliconazole (LLCZ). Thirteen tinea pedis patients found to be positive on KOH examination were assessed by mycological examinations and quantitative real-time polymerase chain reaction (PCR) targeted internal transcribed spacer (ITS) in ribosomal RNA gene at the initial visit and after 2 and 4 weeks of treatment. Assays showed that the average copy number of ITS DNA had significantly decreased to 22.9% at 2 weeks and 4.8% at 4 weeks compared with the initial visit. LLCZ topical treatment could defeat almost pathogenic dermatophytes in the scales within 4 weeks.

scholarly journals Comparative transcriptome and histological analyses of wheat in response to phytotoxic aphid Schizaphis graminum and non-phytotoxic aphid Sitobion avenae feeding

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yong Zhang ◽  
Yu Fu ◽  
Jia Fan ◽  
Qian Li ◽  
Frédéric Francis ◽  
...  
Keyword(s):  
Plant Defence ◽  
Sitobion Avenae ◽  
Schizaphis Graminum ◽  
Wheat Varieties ◽  
Leaf Chlorosis ◽  
Defence Genes ◽  
Genes Encoding ◽  
Defence Responses ◽  
Wheat Leaves ◽  
Ethylene Signalling

Abstract Background Infestation of the phytotoxic aphid Schizaphis graminum can rapidly induce leaf chlorosis in susceptible plants, but this effect is not observed with the nonphytotoxic aphid Sitobion avenae. However, few studies have attempted to identify the different defence responses induced in wheat by S. graminum and S. avenae feeding and the mechanisms underlying the activation of chlorosis by S. graminum feeding. Results S. graminum feeding significantly reduced the chlorophyll content of wheat leaves, and these effects were not observed with S. avenae. A transcriptomic analysis showed that the expression levels of genes involved in the salicylic acid, jasmonic acid and ethylene signalling defence pathways were significantly upregulated by both S. avenae and S. graminum feeding; however, more plant defence genes were activated by S. graminum feeding than S. avenae feeding. The transcript levels of genes encoding cell wall-modifying proteins were significantly increased after S. graminum feeding, but only a few of these genes were induced by S. avenae. Furthermore, various reactive oxygen species-scavenging genes, such as 66 peroxidase (POD) and 8 ascorbate peroxidase (APx) genes, were significantly upregulated after S. graminum feeding, whereas only 15 POD and one APx genes were induced by S. avenae feeding. The activity of four antioxidant enzymes was also significantly upregulated by S. graminum feeding. Cytological examination showed that S. graminum feeding induced substantial hydrogen peroxide (H2O2) accumulation in wheat leaves. The chlorosis symptoms and the loss of chlorophyll observed in wheat leaves after S. graminum feeding were reduced and inhibited by the scavenging of H2O2 by dimethylthiourea, which indicated that H2O2 plays important role in the induction of chlorosis by S. graminum feeding. Conclusions S. graminum and S. avenae feeding induces the JA, SA and ET signalling pathways, but S. graminum activated stronger plant defence responses than S. avenae. S. graminum feeding triggers strong ROS-scavenging activity and massive H2O2 production in wheat leaves, and the accumulation of H2O2 induced by S. graminum feeding is involved in the activation of chlorosis in wheat leaves. These results enhance our understanding of mechanisms underlying aphid-wheat interactions and provide clues for the development of aphid-resistant wheat varieties.

GPVI: the inside story

Blood ◽  
2009 ◽  
Vol 114 (9) ◽  
pp. 1723-1724 ◽  
Author(s):  
Alan Nurden
Keyword(s):  
Signal Transduction ◽  
Copy Number ◽  
Platelet Reactivity ◽  
Low Frequency

The search is on for natural regulators of platelet reactivity. In this issue of Blood, Trifiro and colleagues confirm that the low frequency isoform of platelet GPVI (VIb) attenuates ligand-mediated signal transduction and dampens down platelet reactivity with collagen while not affecting GPVI receptor copy number.

scholarly journals Identification and characterization of a natural polymorphism in FT-A2 associated with increased number of grains per spike in wheat

2021 ◽  
Author(s):  
Priscilla Glenn ◽  
Junli Zhang ◽  
Gina Brown-Guedira ◽  
Noah DeWitt ◽  
Jason P. Cook ◽  
...  
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Tetraploid Wheat ◽  
Low Frequency ◽  
Yield Component ◽  
Loss Of Function ◽  
Grain Number ◽  
Wheat Varieties ◽  
Positive Effects ◽  
Grain Number Per Spike

Abstract Key message We discovered a natural FT-A2 allele that increases grain number per spike in both pasta and bread wheat with limited effect on heading time. Abstract Increases in wheat grain yield are necessary to meet future global food demands. A previous study showed that loss-of-function mutations in FLOWERING LOCUS T2 (FT2) increase spikelet number per spike (SNS), an important grain yield component. However, these mutations were also associated with reduced fertility, offsetting the beneficial effect of the increases in SNS on grain number. Here, we report a natural mutation resulting in an aspartic acid to alanine change at position 10 (D10A) associated with significant increases in SNS and no negative effects on fertility. Using a high-density genetic map, we delimited the SNS candidate region to a 5.2-Mb region on chromosome 3AS including 28 genes. Among them, only FT-A2 showed a non-synonymous polymorphism (D10A) present in two different populations segregating for the SNS QTL on chromosome arm 3AS. These results, together with the known effect of the ft-A2 mutations on SNS, suggest that variation in FT-A2 is the most likely cause of the observed differences in SNS. We validated the positive effects of the A10 allele on SNS, grain number, and grain yield per spike in near-isogenic tetraploid wheat lines and in an hexaploid winter wheat population. The A10 allele is present at very low frequency in durum wheat and at much higher frequency in hexaploid wheat, particularly in winter and fall-planted spring varieties. These results suggest that the FT-A2 A10 allele may be particularly useful for improving grain yield in durum wheat and fall-planted common wheat varieties.

Sign in / Sign up

Export Citation Format

Share Document