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1.
Tumour Biol ; 45(1): 31-54, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37574746

RESUMO

BACKGROUND: Lack of druggable targets and complex expression heterogeneity of known targets is common among TNBC subtypes. An enhanced expression of galectin-3 in TNBCs has already been documented. We have observed a tumor progression-dependent galectin-3 expression in TNBCs compared to adjacent epithelium and non TNBCs. OBJECTIVE: To unravel the association of galectin- 3 in tumor progression, aggressiveness and drug resistance in TNBC patients. METHODS: Galectin-3 expression in 489 breast cancer tissues was correlated with clinicopathological features and the results were validated in cell lines and mouse model by silencing galectin-3 using shRNA and the proteins were profiled by western blot and qRT-PCR. Protein interaction was analyzed by GFP Trap and Mass spectrometry. RESULTS: Galectin-3 expression correlated with tumor stage in TNBC and a lower galectin-3 expression was associated with poor patient survival. The positive correlation between galectin-3, vimentin and CD44 expression, pinpoints galectin-3 contribution to epithelial to mesenchymal transition, drug resistance and stemness. Vimentin was found as an interacting partner of galectin-3. Duplexing of galecin-3 and vimentin in patient samples revealed the presence of tumor cells co-expressing both galectin-3 and vimentin. In vitro studies also showed its role in tumor cell survival and metastatic potential, elementary for tumor progression. In vivo studies further confirmed its metastatic potential. CONCLUSIONS: Tumor progression dependent expression pattern of galectin 3 was found to indicate prognosis. Co-expression of galectin-3 and vimentin in tumor cells promotes tumor dissemination, survival and its metastatic capability in TNBCs.


Assuntos
Neoplasias de Mama Triplo Negativas , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Movimento Celular/genética , Transição Epitelial-Mesenquimal/genética , Galectina 3/genética , Galectina 3/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Vimentina/genética , Vimentina/metabolismo
2.
Plants (Basel) ; 11(5)2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35270092

RESUMO

Major biotic stresses viz., bacterial blight (BB) and blast and brown plant hopper (BPH) coupled with abiotic stresses like drought stress, significantly affect rice yields. To address this, marker-assisted intercross (IC) breeding involving multiple donors was used to combine three BB resistance genes-xa5, xa13 and Xa21, two blast resistance genes-Pi9 and Pi54, two BPH resistance genes-Bph20 and Bph21, and four drought tolerant quantitative trait loci (QTL)-qDTY1.1, qDTY2.1, qDTY3.1 and qDTY12.1-in the genetic background of the elite Indian rice cultivar 'Krishna Hamsa'. Three cycles of selective intercrossing followed by selfing coupled with foreground selection and phenotyping for the target traits resulted in the development of 196 introgression lines (ILs) with a myriad of gene/QTL combinations. Based on the phenotypic reaction, the ILs were classified into seven phenotypic classes of resistance/tolerance to the following: (1) BB, blast and drought-5 ILs; (2) BB and blast-10 ILs; (3) BB and drought-9 ILs; (4) blast and drought-42 ILs; (5) BB-3 ILs; (6) blast-84 ILs; and (7) drought-43 ILs; none of the ILs were resistant to BPH. Positive phenotypic response (resistance) was observed to both BB and blast in 2 ILs, BB in 9 ILs and blast in 64 ILs despite the absence of corresponding R genes. Inheritance of resistance to BB and/or blast in such ILs could be due to the unknown genes from other parents used in the breeding scheme. Negative phenotypic response (susceptibility) was observed in 67 ILs possessing BB-R genes, 9 ILs with blast-R genes and 9 ILs harboring QTLs for drought tolerance. Complex genic interactions and recombination events due to the involvement of multiple donors explain susceptibility in some of the marker positive ILs. The present investigation successfully demonstrates the possibility of rapid development of multiple stress-tolerant/resistant ILs in the elite cultivar background involving multiple donors through selective intercrossing and stringent phenotyping. The 196 ILs in seven phenotypic classes with myriad of gene/QTL combinations will serve as a useful genetic resource in combining multiple biotic and abiotic stress resistance in future breeding programs.

3.
Tumour Biol ; 43(1): 77-96, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33998569

RESUMO

Cancer metastasis and therapy resistance are the foremost hurdles in oncology at the moment. This review aims to pinpoint the functional aspects of a unique multifaceted glycosylated molecule in both intracellular and extracellular compartments of a cell namely galectin-3 along with its metastatic potential in different types of cancer. All materials reviewed here were collected through the search engines PubMed, Scopus, and Google scholar. Among the 15 galectins identified, the chimeric gal-3 plays an indispensable role in the differentiation, transformation, and multi-step process of tumor metastasis. It has been implicated in the molecular mechanisms that allow the cancer cells to survive in the intravascular milieu and promote tumor cell extravasation, ultimately leading to metastasis. Gal-3 has also been found to have a pivotal role in immune surveillance and pro-angiogenesis and several studies have pointed out the importance of gal-3 in establishing a resistant phenotype, particularly through the epithelial-mesenchymal transition process. Additionally, some recent findings suggest the use of gal-3 inhibitors in overcoming therapeutic resistance. All these reports suggest that the deregulation of these specific lectins at the cellular level could inhibit cancer progression and metastasis. A more systematic study of glycosylation in clinical samples along with the development of selective gal-3 antagonists inhibiting the activity of these molecules at the cellular level offers an innovative strategy for primary cancer prevention.


Assuntos
Proteínas Sanguíneas/metabolismo , Carcinogênese/patologia , Epigênese Genética/genética , Galectinas/metabolismo , Neoplasias/patologia , Apoptose/fisiologia , Proteínas Sanguíneas/genética , Carcinogênese/genética , Transição Epitelial-Mesenquimal/genética , Galectinas/genética , Glicosilação , Humanos , Metástase Neoplásica/patologia , Neoplasias/genética
4.
Field Crops Res ; 260: 107977, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33390645

RESUMO

The complexity of genotype × environment interactions under drought reduces heritability, which determines the effectiveness of selection for drought tolerance and development of drought tolerant varieties. Genetic progress measured through changes in yield performance over time is important in determining the efficiency of breeding programmes in which test cultivars are replaced each year on the assumption that the new cultivars will surpass the older cultivars. The goal of our study was to determine the annual rate of genetic gain for rice grain yield in a drought-prone rainfed system in a series of multi-environment trials conducted from 2005 to 2014 under the Drought Breeding Network of Indian sites in collaboration with the International Rice Research Institute (IRRI). Our results show a positive trend in grain yield with an annual genetic yield increase of about 0.68 % under irrigated control, 0.87 % under moderate reproductive stage drought stress and 1.9 % under severe reproductive stage drought stress due to breeding efforts. The study also demonstrates the effectiveness of direct selection for grain yield under both irrigated control as well as managed drought stress screening to improve yield in typical rainfed systems. IRRI's drought breeding programme has exhibited a significant positive trend in genetic gain for grain yield over the years under both drought stress as well as favorable irrigated control conditions. Several drought tolerant varieties released from the programme have outperformed the currently grown varieties under varied conditions in the rainfed environments on farmers' fields.

5.
Rev Sci Instrum ; 92(12): 124705, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34972462

RESUMO

In many low-noise applications, extracting information from the extremely noisy signal is required. This task can be accomplished by a lock-in amplifier if the frequency of the signal is known before detection. Error signal output from the physics package of the rubidium atomic clock (RbAC) is one of those noisy signals. A lock-in amplifier extracts the desired information from such a signal as the frequency of the error signal is known beforehand. The Space Applications Centre of the Indian Space Research Organisation is developing the Indian Rubidium Atomic Frequency Standard (IRAFS) for Navigation with Indian Constellation. We have developed a digital lock-in amplifier with a very high-resolution frequency control voltage for IRAFS. This paper demonstrates the digital lock-in amplifier with a novel method of combining two 12-bit digital-to-analog converters (DACs) to get higher resolution 20-bit output for precise frequency control and tuning. This design technique allows a digital lock-in amplifier to be used for high-performance RbAC for space applications as precision DACs with higher resolution are not available in space-qualified versions.

6.
Rice (N Y) ; 13(1): 29, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32472217

RESUMO

BACKGROUND: Unfavorable climatic changes have led to an increased threat of several biotic and abiotic stresses over the past few years. Looking at the massive damage caused by these stresses, we undertook a study to develop high yielding climate-resilient rice, using genes conferring resistance against blast (Pi9), bacterial leaf blight (BLB) (Xa4, xa5, xa13, Xa21), brown planthopper (BPH) (Bph3, Bph17), gall midge (GM) (Gm4, Gm8) and QTLs for drought tolerance (qDTY1.1 and qDTY3.1) through marker-assisted forward breeding (MAFB) approach. RESULT: Seven introgression lines (ILs) possessing a combination of seven to ten genes/QTLs for different biotic and abiotic stresses have been developed using marker-assisted selection (MAS) breeding method in the background of Swarna with drought QTLs. These ILs were superior to the respective recurrent parent in agronomic performance and also possess preferred grain quality with intermediate to high amylose content (AC) (23-26%). Out of these, three ILs viz., IL1 (Pi9+ Xa4+ xa5+ Xa21+ Bph17+ Gm8+ qDTY1.1+ qDTY3.1), IL6 (Pi9+ Xa4+ xa5+ Xa21+ Bph3+ Bph17+ Gm4+ Gm8+ qDTY1.1+ qDTY3.1) and IL7 (Pi9+ Xa4+ xa5+ Bph3+ Gm4+ qDTY1.1+ qDTY3.1) had shown resistance\tolerance for multiple biotic and abiotic stresses both in the field and glasshouse conditions. Overall, the ILs were high yielding under various stresses and importantly they also performed well in non-stress conditions without any yield penalty. CONCLUSION: The current study clearly illustrated the success of MAS in combining tolerance to multiple biotic and abiotic stresses while maintaining higher yield potential and preferred grain quality. Developed ILs with seven to ten genes in the current study showed superiority to recurrent parent Swarna+drought for multiple-biotic stresses (blast, BLB, BPH and GM) together with yield advantages of 1.0 t ha- 1 under drought condition, without adverse effect on grain quality traits under non-stress.

7.
Bioinformation ; 16(9): 695-701, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34621115

RESUMO

It is of interest to list plants and its usage in olden days. The history of plants is closely related with the history of medicine since time immemorial. Various literature data shows the usage of medicinal plants. It is linked to various system of medicine like Siddha, Ayurveda and Unani. This is in practice for more than 5000 years. People in olden age had a detailed knowledge on these plants. Hence, we collected such data from the first five volumes of Epigraphia Indica, which was published, by the Archeological survey of India from 1882 to 1977. These data provides a framework on various plants and its usage in various ways, in different time period in human history. This helps us to drive valuable bio-medical information for application in modern scientific biomedical methods. We further plan to sort and glean such data so as to help in evaluating the total biomedical data in Epigraphia Indica to extract useful biological knowledge for application in evidence-based biomedicine.

8.
J Genet ; 982019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31819024

RESUMO

The brown planthopper (BPH) Nilaparvata lugens (Stål) (Homoptera: Delphacidae) is considered a threat to rice (Oryza sativa ssp.) crop in many parts of the world including India. Among the BPH-resistance (R) genes so far reported in rice, most of them are ineffective against BPH biotype 4 predominant in the Indian sub-continent. In this study, we show the introgression line RPBio4918-230S was identified as BPH resistant after five years of rigorous screening at seedling stage and two years at tillering and reproductive stages. The inheritance of resistance indicated that two recessive genes are involved at seedling and reproductive stages. The allelic relation with known genes using linked reported markers suggested that the genes present in RPBio4918-230S are different. We report here the genetics of the two newly introgressed BPH resistance genes from O. nivara in the background of Swarna which are effective at all the important growth stages. The genes have been tentatively named as bph39(t) and bph40(t). The honeydew area (feeding rate) and days to wilt parameters observed at 30 days after sowing in BC1F3 indicated that newly introgressed genes have both antibiosis and tolerance mechanisms for resistance. The BPH resistance genes identified in this study would facilitate the breeding of broad spectrum and durable resistance in rice against BPH biotype 4.


Assuntos
Genes de Plantas/genética , Hemípteros , Oryza/genética , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Animais , Cruzamento , Mapeamento Cromossômico , Cruzamentos Genéticos , Resistência à Doença/genética , Oryza/parasitologia , Floema , Característica Quantitativa Herdável , Xilema
9.
Sci Rep ; 9(1): 8136, 2019 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-31148549

RESUMO

Micronutrient especially iron and zinc-enriched rice hold immense promise for sustainable and cost-effective solutions to overcome malnutrition. In this context, BC2F5 population derived from cross between RP-Bio226 and Sampada was used to localize genomic region(s)/QTL(s) for grain Fe (iron) and Zn (zinc) content together with yield and yield-related traits. Genotyping of mapping population with 108 SSR markers resulted in a genetic map of 2317.5 cM with an average marker distance of 21.5 cM. Mean grain mineral content in the mapping population across the two seasons ranged from 10.5-17.5 ppm for Fe and 11.3-22.1 ppm for Zn. Based on the multi-season phenotypic data together with genotypic data, a total of two major QTLs for Fe (PVE upto 17.1%) and three for Zn (PVE upto 34.2%) were identified. Comparative analysis across the two seasons has revealed four consistent QTLs for Fe (qFe1.1, qFe1.2, qFe6.1 and qFe6.2) and two QTL for Zn content (qZn1.1 and qZn6.2). Additionally, based on the previous and current studies three meta-QTLs for grain Fe and two for grain Zn have been identified. In-silico analysis of the identified QTL regions revealed the presence of potential candidate gene(s) such as, OsPOT, OsZIP4, OsFDR3, OsIAA5 etc., that were previously reported to influence grain Fe and Zn content. The identified QTLs could be utilized in developing high yielding, Fe and Zn denser varieties by marker assisted selection (MAS).


Assuntos
Cruzamentos Genéticos , Ferro/química , Oryza/genética , Zinco/química , Mapeamento Cromossômico , Grão Comestível/química , Grão Comestível/genética , Genes de Plantas , Marcadores Genéticos , Genótipo , Micronutrientes , Repetições de Microssatélites , Oryza/química , Fenótipo , Melhoramento Vegetal , Locos de Características Quantitativas , Estações do Ano
10.
Rice (N Y) ; 12(1): 8, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30778782

RESUMO

BACKGROUND: Climate extremes such as drought and flood have become major constraints to the sustainable rice crop productivity in rainfed environments. Availability of suitable climate-resilient varieties could help farmers to reduce the grain yield losses resulting from the climatic extremities. The present study was undertaken with an aim to develop high-yielding drought and submergence tolerant rice varieties using marker assisted introgression of qDTY1.1, qDTY2.1, qDTY3.1 and Sub1. Performance of near isogenic lines (NILs) developed in the background of Swarna was evaluated across 60 multi-locations trials (MLTs). The selected promising lines from MLTs were nominated and evaluated in national trials across 18 locations in India and 6 locations in Nepal. RESULTS: Grain yield advantage of the NILs with qDTY1.1 + qDTY2.1 + qDTY3.1 + Sub1 and qDTY2.1 + qDTY3.1 + Sub1 ranged from 76 to 2479 kg ha- 1 and 396 to 2376 kg ha- 1 under non-stress (NS) respectively and 292 to 1118 kg ha- 1 and 284 to 2086 kg ha- 1 under reproductive drought stress (RS), respectively. The NIL, IR96322-34-223-B-1-1-1-1 having qDTY1.1 + qDTY2.1 + qDTY3.1 + Sub1 has been released as variety CR dhan 801 in India. IR 96321-1447-651-B-1-1-2 having qDTY1.1 + qDTY3.1 + Sub 1 and IR 94391-131-358-19-B-1-1-1 having qDTY3.1 + Sub1 have been released as varieties Bahuguni dhan-1' and 'Bahuguni dhan-2' respectively in Nepal. Background recovery of 94%, 93% and 98% was observed for IR 96322-34-223-B-1-1-1-1, IR 96321-1447-651-B-1-1-2 and IR 94391-131-358-19-B-1-1-1 respectively on 6 K SNP Infinium chip. CONCLUSION: The drought and submergence tolerant rice varieties with pyramided multiple QTLs can ensure 0.2 to 1.7 t ha- 1 under reproductive stage drought stress and 0.1 to 1.0 t ha- 1 under submergence conditions with no yield penalty under non-stress to farmers irrespective of occurrence of drought and/or flood in the same or different seasons.

11.
J Org Chem ; 83(16): 9530-9537, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-30037227

RESUMO

A rapid and efficient synthesis of aminotetrazole from aryl azides, isocyanides, and TMSN3 is developed. The reaction is promoted by sequential Pd(0)/Fe(III) catalysis. The reaction sequence utilizes the Pd-catalyzed azide-isocyanide denitrogenative coupling reaction to generate unsymmetric carbodiimide in situ, which reacts with TMSN3 in the presence of FeCl3 in a single pot. The methodology has distinct advantages over traditional synthetic approaches where toxic Hg and Pb salts are employed at stoichiometric scale.

12.
Plant Soil ; 417(1): 377-392, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-31258196

RESUMO

AIMS: Drought is the major constraint to rainfed rice productivity in South Asia, but few reports provide detailed characterization of the soil properties related to drought stress severity in the region. The aim of the study was to provide a compilation of drought breeding network sites and their respective levels of drought stress, and to relate soil parameters with yield reduction by drought. METHODS: This study characterized levels of drought stress and soil nutrient and physical properties at 18 geographically distributed research station sites involved in rice varietal screening in Bangladesh, India, and Nepal, as well as at farmers' fields located near the research stations. RESULTS: Based on soil resistance to penetration profiles, a hardpan was surprisingly absent at about half of the sites characterized. Significant relationships of depth of compaction and yield reduction by drought indicated the effects of soil puddling on susceptibility to cracking, rather than water retention by hardpans, on plant water availability in this region. The main difference between research stations and nearby farmers' fields was in terms of soil compaction. CONCLUSIONS: These results present an initiative for understanding the range of severities of reproductive-stage drought stress in drought-prone rainfed lowland rice-growing areas in South Asia.

13.
Org Lett ; 18(3): 356-9, 2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26761401

RESUMO

A ruthenium catalyzed intramolecular C-S coupling reaction of N-arylthioureas for the synthesis of 2-aminobenzothiazoles has been developed. Kinetic, isotope labeling, and computational studies reveal the involvement of an electrophilic ruthenation pathway instead of a direct C-H activation. Stereoelectronic effect of meta-substituents on the N-arylthiourea dictates the final regioselective outcome of the reaction.

14.
Plant Sci ; 242: 278-287, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26566845

RESUMO

Rice is a staple cereal of India cultivated in about 43.5Mha area but with relatively low average productivity. Abiotic factors like drought, flood and salinity affect rice production adversely in more than 50% of this area. Breeding rice varieties with inbuilt tolerance to these stresses offers an economically viable and sustainable option to improve rice productivity. Availability of high quality reference genome sequence of rice, knowledge of exact position of genes/QTLs governing tolerance to abiotic stresses and availability of DNA markers linked to these traits has opened up opportunities for breeders to transfer the favorable alleles into widely grown rice varieties through marker-assisted backcross breeding (MABB). A large multi-institutional project, "From QTL to variety: marker-assisted breeding of abiotic stress tolerant rice varieties with major QTLs for drought, submergence and salt tolerance" was initiated in 2010 with funding support from Department of Biotechnology, Government of India, in collaboration with International Rice Research Institute, Philippines. The main focus of this project is to improve rice productivity in the fragile ecosystems of eastern, northeastern and southern part of the country, which bear the brunt of one or the other abiotic stresses frequently. Seven consistent QTLs for grain yield under drought, namely, qDTY1.1, qDTY2.1, qDTY2.2, qDTY3.1, qDTY3.2, qDTY9.1 and qDTY12.1 are being transferred into submergence tolerant versions of three high yielding mega rice varieties, Swarna-Sub1, Samba Mahsuri-Sub1 and IR 64-Sub1. To address the problem of complete submergence due to flash floods in the major river basins, the Sub1 gene is being transferred into ten highly popular locally adapted rice varieties namely, ADT 39, ADT 46, Bahadur, HUR 105, MTU 1075, Pooja, Pratikshya, Rajendra Mahsuri, Ranjit, and Sarjoo 52. Further, to address the problem of soil salinity, Saltol, a major QTL for salt tolerance is being transferred into seven popular locally adapted rice varieties, namely, ADT 45, CR 1009, Gayatri, MTU 1010, PR 114, Pusa 44 and Sarjoo 52. Genotypic background selection is being done after BC2F2 stage using an in-house designed 50K SNP chip on a set of twenty lines for each combination, identified with phenotypic similarity in the field to the recipient parent. Near-isogenic lines with more than 90% similarity to the recipient parent are now in advanced generation field trials. These climate smart varieties are expected to improve rice productivity in the adverse ecologies and contribute to the farmer's livelihood.


Assuntos
Secas , Inundações , Oryza/genética , Locos de Características Quantitativas/genética , Tolerância ao Sal/genética , Adaptação Fisiológica/genética , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Marcadores Genéticos/genética , Programas Governamentais , Índia , Oryza/crescimento & desenvolvimento , Melhoramento Vegetal/métodos , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Seleção Artificial
15.
J Exp Bot ; 65(21): 6265-78, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25205576

RESUMO

The increased occurrence and severity of drought stress have led to a high yield decline in rice in recent years in drought-affected areas. Drought research at the International Rice Research Institute (IRRI) over the past decade has concentrated on direct selection for grain yield under drought. This approach has led to the successful development and release of 17 high-yielding drought-tolerant rice varieties in South Asia, Southeast Asia, and Africa. In addition to this, 14 quantitative trait loci (QTLs) showing a large effect against high-yielding drought-susceptible popular varieties were identified using grain yield as a selection criterion. Six of these (qDTY 1.1 , qDTY 2.2 , qDTY 3.1 , qDTY 3.2 , qDTY 6.1 , and qDTY 12.1 ) showed an effect against two or more high-yielding genetic backgrounds in both the lowland and upland ecosystem, indicating their usefulness in increasing the grain yield of rice under drought. The yield of popular rice varieties IR64 and Vandana has been successfully improved through a well-planned marker-assisted backcross breeding approach, and QTL introgression in several other popular varieties is in progress. The identification of large-effect QTLs for grain yield under drought and the higher yield increase under drought obtained through the use of these QTLs (which has not been reported in other cereals) indicate that rice, because of its continuous cultivation in two diverse ecosystems (upland, drought tolerant, and lowland, drought susceptible), has benefited from the existence of larger genetic variability than in other cereals. This can be successfully exploited using marker-assisted breeding.


Assuntos
Cruzamento/métodos , Secas , Oryza/genética , Locos de Características Quantitativas , Seleção Genética , Biomassa , Interação Gene-Ambiente , Variação Genética , Oryza/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento
16.
Phytopathology ; 102(2): 222-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21970567

RESUMO

Broadening of the genetic base for identification and transfer of genes for resistance to insect pests and diseases from wild relatives of rice is an important strategy in resistance breeding programs across the world. An accession of Oryza nivara, International Rice Germplasm Collection (IRGC) accession number 105710, was identified to exhibit high level and broad-spectrum resistance to Xanthomonas oryzae pv. oryzae. In order to study the genetics of resistance and to tag and map the resistance gene or genes present in IRGC 105710, it was crossed with the bacterial blight (BB)-susceptible varieties 'TN1' and 'Samba Mahsuri' (SM) and then backcrossed to generate backcross mapping populations. Analysis of these populations and their progeny testing revealed that a single dominant gene controls resistance in IRGC 105710. The BC(1)F(2) population derived from the cross IRGC 105710/TN1//TN1 was screened with a set of 72 polymorphic simple-sequence repeat (SSR) markers distributed across the rice genome and the resistance gene was coarse mapped on chromosome 7 between the SSR markers RM5711 and RM6728 at a genetic distance of 17.0 and 19.3 centimorgans (cM), respectively. After analysis involving 49 SSR markers located between the genomic interval spanned by RM5711 and RM6728, and BC(2)F(2) population consisting of 2,011 individuals derived from the cross IRGC 105710/TN1//TN1, the gene was fine mapped between two SSR markers (RMWR7.1 and RMWR7.6) located at a genetic distance of 0.9 and 1.2 cM, respectively, from the gene and flanking it. The linkage distances were validated in a BC(1)F(2) mapping population derived from the cross IRGC 105710/SM//2 × SM. The BB resistance gene present in the O. nivara accession was identified to be novel based on its unique map location on chromosome 7 and wider spectrum of BB resistance; this gene has been named Xa33. The genomic region between the two closely flanking SSR markers was in silico analyzed for putatively expressed candidate genes. In total, eight genes were identified in the region and a putative gene encoding serinethreonine kinase appears to be a candidate for the Xa33 gene.


Assuntos
Resistência à Doença/genética , Oryza/genética , Doenças das Plantas/imunologia , Proteínas Serina-Treonina Quinases/genética , Xanthomonas/imunologia , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Cruzamentos Genéticos , Genes de Plantas/genética , Ligação Genética , Marcadores Genéticos/genética , Repetições de Microssatélites/genética , Oryza/imunologia , Oryza/microbiologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Locos de Características Quantitativas/genética
17.
Genet Res (Camb) ; 93(6): 397-408, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22189605

RESUMO

The cultivar Ajaya (IET 8585) exhibits durable broad-spectrum resistance to bacterial blight (BB) disease of rice and is widely used as a resistance donor. The present study was carried out to decipher the genetics of BB resistance in Ajaya and map the gene(s) conferring resistance. Genetic analysis in the F2 indicated a quantitative/additive nature of resistance governed by two loci with equal effects. Linked marker analysis and allelic tests revealed that one of the resistance genes is xa5. Sequence analysis of a 244 bp region of the second exon of the gene-encoding Transcription factor IIAγ (the candidate gene for xa5) confirmed the presence of xa5. Bulked-segregant analysis (BSA) revealed the putative location of the two quantitative trait loci (QTLs)/genes associated with resistance on chromosomes 5 and 8. Composite interval mapping located the first locus on Chr. 5S exactly in the genomic region spanned by xa5 and the second locus (qtl BBR 8.1) on Chr. 8L. Owing to its differential disease reaction with a set of seven hyper-virulent isolates of Xanthomonas oryzae, a map location on Chr. 8L, which was distinct from xa13 and data from allelism tests, the second resistance locus in Ajaya was determined to be novel and was designated as xaAj. A contig map spanning xaAj was constructed in silico and the genomic region was delimited to a 13.5 kb physical interval. In silico analysis of the genomic region spanning xaAj identified four putatively expressed candidate genes, one of which could be involved in imparting BB resistance in Ajaya along with xa5.


Assuntos
Mapeamento Cromossômico/métodos , Oryza/genética , Doenças das Plantas/genética , Locos de Características Quantitativas/genética , Sequência de Bases , Cromossomos de Plantas/genética , Cruzamentos Genéticos , Resistência à Doença/genética , Genes de Plantas/genética , Padrões de Herança/genética , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Oryza/microbiologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Polimorfismo Genético , Homologia de Sequência do Ácido Nucleico , Virulência , Xanthomonas/patogenicidade
18.
Int J Gynecol Cancer ; 20(6): 1046-51, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20683415

RESUMO

HYPOTHESIS: Assessment of the prevalence and type distribution of human papillomavirus (HPV) in squamous cell carcinomas (SCC) of the cervix across India was undertaken to estimate the impact of available prophylactic HPV-L1 vaccines in the country and to find out additional types that might be needed to be incorporated in second-generation vaccines. METHODS: High-risk (HR) HPVs were genotyped from 667 histopathologically confirmed cases of SCC from 6 different centers representing 4 regions across India: Advanced Centre for Treatment, Research and Education in Cancer, Mumbai; All India Institute of Medical Sciences, New Delhi; Cancer Foundation of India, Kolkata; Christian Medical College, Vellore; Kidwai Memorial Institute of Oncology, Bangalore; and Regional Cancer Center, Thiruvananthapuram. Human papillomaviruses in tumor biopsies were analyzed by Xcytonscreen HPV based on PGMY09/11 multiplex polymerase chain reaction and reverse dot blot assay. RESULTS: Overall viral prevalence across India was not different; 92.1% of 667 cases harbored HPV; 8% were negative. Infection with single HR type was seen in 86.8%: predominant types being HPV-16 followed by HPV-18, -45, -73, -31, -56, -52, -58, -59, -33, -68, -51, -35, -26, and -39. Human papillomavirus types 16/18-positive fraction formed 79.6%; other types comprised 12.4%. CONCLUSIONS: Prophylactic HPV-16/18-L1 vaccines would provide greater than 75% protection against SCC in India. Ranking and frequencies of non-16/18 types were different from earlier reports. Hence, considering the possibility of promotion of persistence of nonvaccine types in the vaccinees due to original antigenic sin and the lack of organized screening programs in India, a broad-based vaccine approach would be appropriate.


Assuntos
Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/virologia , Infecções por Papillomavirus/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/virologia , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Carcinoma de Células Escamosas/patologia , Estudos de Coortes , DNA Viral/análise , Feminino , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/isolamento & purificação , Humanos , Imuno-Histoquímica , Índia/epidemiologia , Pessoa de Meia-Idade , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/administração & dosagem , Reação em Cadeia da Polimerase , Lesões Pré-Cancerosas/epidemiologia , Lesões Pré-Cancerosas/patologia , Prevalência , Medição de Risco , Neoplasias do Colo do Útero/patologia , Esfregaço Vaginal
19.
Int J Cancer ; 125(1): 91-103, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-19358280

RESUMO

Human papilloma virus is a causative factor in the etiology of cervical cancer with HPV16 being the most prevalent genotype associated with it. Intratype variations in oncogenic E6/E7 and capsid L1 proteins of HPV 16 besides being of phylogenetic importance, are associated with risk of viral persistence and progression. The objective of this multicentric study was to identify HPV-16 E6, E7 and L1 variants prevalent in India and their possible biological effects. Squamous cell cervical cancer biopsies were collected from 6 centres in India and examined for the presence of HPV 16. Variants of HPV-16 were characterized by full length sequence analysis of L1, E6 and E7 genes in 412 samples. Similar distribution of the variants was seen from the different centres/regions, with the European variant E350G being the most prevalent (58%), followed by American Asian variant (11.4%). Fifty six changes were seen in E6 region, 31 being nonsynonymous. The most frequent being L83V (72.3%), Q14H (13.1%) and H78Y (12.1%). Twenty-nine alterations were seen in E7 region, with 12 being nonsynonymous. The most frequent being F57V (9%). L1 region showed 204 changes, of which 67 were nonsynonymous. The most frequent being 448insS (100%), and 465delD (100%), H228D (94%), T292A (85%). The identified variants some new and some already reported can disrupt pentamer formation, transcriptional regulation of the virus, L1 protein interface interaction, B and T cell epitopes, p53 degradation, and thus their distribution is important for development of HPV diagnostics, vaccine, and for therapeutic purpose.


Assuntos
Proteínas do Capsídeo/genética , Variação Genética , Papillomavirus Humano 16/genética , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/genética , Proteínas Repressoras/genética , Neoplasias do Colo do Útero/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/virologia , Feminino , Papillomavirus Humano 16/classificação , Humanos , Índia , Pessoa de Meia-Idade , Proteínas E7 de Papillomavirus , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/virologia , Neoplasias do Colo do Útero/virologia
20.
Clin Oncol (R Coll Radiol) ; 21(6): 488-93, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19386478

RESUMO

AIMS: Cisplatin-based chemotherapy with radiotherapy is currently the standard treatment for locally advanced carcinoma of the cervix. Recent studies have shown a better response with the addition of newer chemotherapeutic agents. The aim of this phase I study was to establish the maximum tolerated dose (MTD) of paclitaxel in combination with cisplatin as a radiosensitiser along with radiation therapy in the treatment of carcinoma of the cervix and to analyse the toxicity profile of the combination regimen. MATERIALS AND METHODS: In total, 21 newly diagnosed patients with squamous cell carcinoma of the cervix, International Federation of Gynecology and Obstetrics stage IB to IIIB were included in this trial. All patients received external beam radiation therapy to the pelvis (50 Gy in 25 fractions) delivered by conventional four-field box technique followed by low dose rate brachytherapy. Concurrent chemotherapy was administered with weekly cisplatin (30 mg/m(2)) and an escalating dose of weekly paclitaxel starting at 10 mg/m(2) up to 50 mg/m(2) (according to the modified Fibonacci series). RESULTS: The MTD of weekly paclitaxel was found to be 40 mg/m(2). The dose-limiting toxicity that occurred in our patients at a dose of 50 mg/m(2) weekly paclitaxel was grade 3 proctitis and vaginitis. CONCLUSION: In this phase I trial of concurrent radiation and combination chemotherapy with weekly paclitaxel and cisplatin (30 mg/m(2)/week), the MTD of paclitaxel was found to be 40 mg/m(2). This combination was feasible, with an acceptable toxicity profile.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/radioterapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Braquiterapia/efeitos adversos , Carcinoma de Células Escamosas/patologia , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Terapia Combinada , Relação Dose-Resposta a Droga , Feminino , Humanos , Dose Máxima Tolerável , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Radioterapia/efeitos adversos , Resultado do Tratamento , Neoplasias do Colo do Útero/patologia
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