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1.
Ann Oncol ; 29(2): 324-331, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29186296

RESUMEN

The success of targeted therapies, including inhibitors of the vascular endothelial growth factor pathway or the mammalian target of rapamycin, in the treatment of metastatic renal cell carcinoma led to interest in testing their efficacy in the adjuvant setting. Results from the first trials are now available, with other studies due to report imminently. This review provides an overview of adjuvant targeted therapy in renal cell carcinoma, including interpretation of currently available conflicting data and future direction of research. We discuss the key differences between the completed targeted therapy adjuvant trials, and highlight the importance of accurately identifying patients who are likely to benefit from adjuvant treatment. We also consider reasons why blinded independent radiology review and treatment dose may prove critical for adjuvant treatment success. The implications of using disease-free survival as a surrogate end point for overall survival from the patient perspective and measurement of health benefit have recently been brought into focus and are discussed. Finally, we discuss how the ongoing adjuvant trials with targeted therapies and checkpoint inhibitors may improve our understanding and ability to prevent tumor recurrence after nephrectomy in the future.


Asunto(s)
Carcinoma de Células Renales/tratamiento farmacológico , Quimioterapia Adyuvante/métodos , Neoplasias Renales/tratamiento farmacológico , Terapia Molecular Dirigida/métodos , Selección de Paciente , Antineoplásicos/uso terapéutico , Carcinoma de Células Renales/mortalidad , Carcinoma de Células Renales/patología , Supervivencia sin Enfermedad , Humanos , Neoplasias Renales/mortalidad , Neoplasias Renales/patología , Recurrencia Local de Neoplasia/patología , Factores de Riesgo , Resultado del Tratamiento
2.
Ann Oncol ; 28(3): 604-610, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-27993815

RESUMEN

Background: The majority of renal cell carcinoma (RCC) studies analyze primary tumors, and the corresponding results are extrapolated to metastatic RCC tumors. However, it is unknown if gene expression profiles from primary RCC tumors differs from patient-matched metastatic tumors. Thus, we sought to identify differentially expressed genes between patient-matched primary and metastatic RCC tumors in order to understand the molecular mechanisms underlying the development of RCC metastases. Patients and methods: We compared gene expression profiles between patient-matched primary and metastatic RCC tumors using a two-stage design. First, we used Affymetrix microarrays on 15 pairs of primary RCC [14 clear cell RCC (ccRCC), 1 papillary] tumors and patient-matched pulmonary metastases. Second, we used a custom NanoString panel to validate seven candidate genes in an independent cohort of 114 ccRCC patients. Differential gene expression was evaluated using a mixed effect linear model; a random effect denoting patient was included to account for the paired data. Third, The Cancer Genome Atlas (TCGA) data were used to evaluate associations with metastasis-free and overall survival in primary ccRCC tumors. Results: We identified and validated up regulation of seven genes functionally involved in the formation of the extracellular matrix (ECM): DCN, SLIT2, LUM, LAMA2, ADAMTS12, CEACAM6 and LMO3. In primary ccRCC, CEACAM6 and LUM were significantly associated with metastasis-free and overall survival (P < 0.01). Conclusions: We evaluated gene expression profiles using the largest set to date, to our knowledge, of patient-matched primary and metastatic ccRCC tumors and identified up regulation of ECM genes in metastases. Our study implicates up regulation of ECM genes as a critical molecular event leading to visceral, bone and soft tissue metastases in ccRCC.


Asunto(s)
Proteínas ADAMTS/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Antígenos CD/genética , Carcinoma de Células Renales/genética , Moléculas de Adhesión Celular/genética , Decorina/genética , Péptidos y Proteínas de Señalización Intercelular/genética , Proteínas con Dominio LIM/genética , Laminina/genética , Lumican/genética , Proteínas del Tejido Nervioso/genética , Adulto , Anciano , Biomarcadores de Tumor/genética , Carcinoma de Células Renales/patología , Supervivencia sin Enfermedad , Matriz Extracelular/genética , Femenino , Proteínas Ligadas a GPI/genética , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Masculino , Análisis por Micromatrices/métodos , Persona de Mediana Edad , Metástasis de la Neoplasia
3.
World J Urol ; 35(3): 367-378, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27342991

RESUMEN

PURPOSE: To review the management of metastatic upper tract urothelial carcinoma (UTUC) including recent advances in targeted and immune therapies as an update to the 2014 joint international consultation on UTUC, co-sponsored by the Société Internationale d'Urologie and International Consultation on Urological Diseases. METHODS: A PubMed database search was performed between January 2013 and May 2016 related to the treatment of metastatic UTUC, and 54 studies were selected for inclusion. RESULTS: The management of patients with metastatic UTUC is primarily an extrapolation from evidence guiding the management of metastatic urothelial carcinoma of the bladder. The first-line therapy for metastatic UTUC is platinum-based combination chemotherapy. Standard second-line therapies are limited and ineffective. Patients with UTUC who progress following platinum-based chemotherapy are encouraged to participate in clinical trials. Recent advances in genomic profiling present exciting opportunities to guide the use of targeted therapy. Immunotherapy with checkpoint inhibitors has demonstrated extremely promising results. Retrospective studies provide support for post-chemotherapy surgery in appropriately selected patients. CONCLUSIONS: The management of metastatic UTUC requires a multi-disciplinary approach. New insights from genomic profiling using targeted therapies, novel immunotherapies, and surgery represent promising avenues for further therapeutic exploration.


Asunto(s)
Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Transicionales/terapia , Neoplasias Renales/patología , Neoplasias Ureterales/patología , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Bevacizumab/administración & dosificación , Carboplatino/administración & dosificación , Carcinoma de Células Transicionales/secundario , Cisplatino/administración & dosificación , Desoxicitidina/administración & dosificación , Desoxicitidina/análogos & derivados , Docetaxel , Humanos , Inmunoterapia , Indoles/administración & dosificación , Pelvis Renal , Niacinamida/administración & dosificación , Niacinamida/análogos & derivados , Paclitaxel/administración & dosificación , Compuestos de Fenilurea/administración & dosificación , Pirroles/administración & dosificación , Sorafenib , Sunitinib , Taxoides/administración & dosificación , Gemcitabina
4.
J Surg Oncol ; 103(2): 105-9, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21259242

RESUMEN

BACKGROUND: Locally recurrent rectal cancer involving the upper sacrum is generally considered a contra-indication to curative surgery. The aim of this study was to determine if a survival benefit was seen in patients undergoing high sacrectomy. METHODS: All patients with locally recurrent rectal cancer involving the sacrum above the 3rd sacral body between 1999 and 2007 were retrospectively reviewed. Kaplan-Meier survival analysis was performed. RESULTS: Nine patients were identified with a median age of 63 years. The proximal extent of sacral resection was through S2 (n = 6), S1 (n = 2), and L5-S1 (n = 1). All patients had R0 negative-margin resection. Median operative time was 13.7 hr, and median operative blood transfusion was 3.7 L. Thirty-day mortality was nil. Postoperative complications requiring surgical intervention occurred in three patients. Local re-recurrence in the pelvis occurred in one patient. The overall median survival was 31 months (range, 2-39 months). Three patients still alive are free of disease after 40, 76, and 101 months, respectively. Ultimately, all deaths were due to metastatic disease. CONCLUSIONS: High sacrectomy that achieves clear margins in patients with recurrent rectal cancer is safe and feasible. A majority will die of metastatic disease, but long-term survival may be possible in some patients.


Asunto(s)
Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/cirugía , Neoplasias del Recto/mortalidad , Neoplasias del Recto/cirugía , Sacro/cirugía , Neoplasias de la Columna Vertebral/secundario , Neoplasias de la Columna Vertebral/cirugía , Adulto , Anciano , Causas de Muerte , Colostomía , Supervivencia sin Enfermedad , Estudios de Factibilidad , Femenino , Humanos , Estimación de Kaplan-Meier , Laparotomía , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Neoplasias de la Columna Vertebral/mortalidad , Derivación Urinaria
5.
Vet Microbiol ; 134(3-4): 254-60, 2009 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-18823724

RESUMEN

The cattle rickettsia Anaplasma marginale is distributed worldwide and is transmitted by about 20 tick species, but only Rhipicephalus simus, a strictly African tick species, has been shown to transmit the vaccine strain of A. centrale. The aim of the present study was to examine transmission of field strains of A. marginale and of the vaccine strain of A. centrale by three tick species -Hyalomma excavatum, Rhipicephalus sanguineus and Rhipicephalus (Boophilus) annulatus - to susceptible calves. Two genetically distinct Israeli field strains of A. marginale, tailed and non-tailed (AmIsT and AmIsNT, respectively), were efficiently transmitted by R. sanguineus, whereas H. excavatum transmitted only the tailed isolate, and R. (Boophilus) annulatus did not transmit A. marginale. None of the three tick species transmitted A. centrale. By means of msp1a primers in PCR assays, amplicons of similar sizes were obtained from either A. marginale-infected calves that were used for acquisition feeding, from R. sanguineus fed on the infected calves, or from calves to which anaplasmosis had been successfully transmitted by these ticks. Although an A. centrale-specific fragment was amplified from salivary glands of R. sanguineus, no transmission to susceptible cattle occurred during 3 months of observation, and anaplasmosis was not induced in splenectomized calves that were subinoculated with blood from calves on which R. sanguineus had fed.


Asunto(s)
Anaplasma centrale/inmunología , Anaplasma marginale/inmunología , Anaplasmosis/inmunología , Vacunas Bacterianas/inmunología , Garrapatas , Animales , Bovinos , Femenino , Masculino , Esplenectomía
6.
Clin Cancer Res ; 6(5): 1896-9, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10815913

RESUMEN

We evaluated p27KIP1 and p21WAF1 expression in 52 patients treated by salvage radical prostatectomy and bilateral pelvic lymphadenectomy for biopsy-proven locally persistent or recurrent prostate cancer after external beam radiation therapy. We defined low and high expression based on the median value observed in our sample. Five-year distant metastasis-free survival and cancer-specific survival were 71 and 82%, respectively, for patients with low expression of p21 (< or =5%), compared with 94 and 100%, respectively, for those with high expression of p21 (>5%; P = 0.02 and 0.01, respectively). Five-year distant metastasis-free survival and cancer-specific survival were 71 and 82%, respectively, for patients with low expression of p27 (<50%), compared with 88 and 96%, respectively, for those with high expression of p27 (> or =50%; P = 0.06 and 0.01, respectively). These findings indicate that p21 and p27 expression levels are significant predictors of survival for patients selected for salvage prostatectomy for recurrent prostate cancer.


Asunto(s)
Proteínas de Ciclo Celular , Ciclinas/biosíntesis , Proteínas Asociadas a Microtúbulos/biosíntesis , Neoplasias de la Próstata/metabolismo , Proteínas Supresoras de Tumor , Anciano , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Modelos de Riesgos Proporcionales , Antígeno Prostático Específico/metabolismo , Prostatectomía , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/terapia , Terapia Recuperativa , Análisis de Supervivencia
7.
Clin Cancer Res ; 5(10): 2820-3, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10537347

RESUMEN

The biological aggressiveness of lymph node-positive prostate cancer is closely linked to cancer volume in nodal metastases. We evaluated MIB-1 (Ki-67) labeling index and bcl-2 expression in primary cancer and matched nodal metastases from 138 node-positive patients treated with radical prostatectomy and bilateral pelvic lymphadenectomy between 1987 and 1992 at the Mayo Clinic. One hundred twenty-eight patients (93%) received androgen deprivation therapy within 90 days after radical prostatectomy. Mean patient age was 66 years (range, 51-78). The median follow-up was 6.7 years (range, 0.03-11). MIB-1 (Ki-67) labeling index was determined by digital image analysis, and nodal cancer volume was determined by the grid method. Systemic progression, defined as the presence of distant metastasis documented by biopsy or radiographic examination, was used as an outcome end point in the Cox proportional hazard models. MIB-1 labeling index in nodal metastases was predictive of systemic progression-free survival (P = 0.001). The 8-year systemic progression-free survival was 100% for those with MIB-1 labeling index <3.5% compared with 78% for those with MIB-1 labeling index > or =7.8%. MIB-1 labeling index correlated with Gleason score, DNA ploidy, and nodal cancer volume (P<0.001, 0.04, and <0.001, respectively). After controlling for nodal cancer volume, MIB-1 labeling index remained significant in predicting systemic progression-free survival (P = 0.047). bcl-2 expression in the primary cancer and lymph node metastasis was associated with systemic progression-free survival in univariate analysis (P = 0.027 and 0.048, respectively) but was not significant after adjusting for nodal cancer volume (P = 0.52 and 0.17, respectively). Our data indicate that assessment of cell proliferation in nodal metastasis is predictive of clinical outcome in prostate cancer patients with regional lymph node metastasis.


Asunto(s)
Neoplasias de la Próstata/patología , Anciano , División Celular , Humanos , Antígeno Ki-67/análisis , Metástasis Linfática , Masculino , Persona de Mediana Edad , Neoplasias de la Próstata/mortalidad , Proteínas Proto-Oncogénicas c-bcl-2/análisis
8.
Prev Vet Med ; 120(2): 232-235, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-25890821

RESUMEN

Neosporosis, caused by the intracellular protozoan Neospora caninum, is a major cause of abortion and reproductive failure in cattle worldwide. The principal route of transmission of neosporosis is via in utero infection of the offspring. There is no effective prophylactic treatment or vaccine available against bovine neosporosis. A N. caninum NcIs491 isolate was examined for its ability to immunize and reduce abortions in naturally infected dairy cows under field conditions. N. caninum-seropositive pregnant dams were inoculated with 10(8) live tachyzoites during mid-term pregnancy. A total of 520 N. caninum seropositive dams were included in this study, of these, 146 were immunized and 374 cows served as a non-vaccinated control group. A significantly lower incidence of abortion was observed in vaccinated compared to non-vaccinated cows, 16 and 26% respectively (P=0.01), with a vaccine efficacy of 39%. However, the number of seropositive offspring remained similar in both groups. Overall, this field trial suggests that vaccination with live N. caninum tachyzoites should be considered as an effective measure to reduce abortions caused by neosporosis in naturally infected cows.


Asunto(s)
Aborto Veterinario/prevención & control , Enfermedades de los Bovinos/prevención & control , Coccidiosis/veterinaria , Neospora/inmunología , Vacunas Antiprotozoos/uso terapéutico , Vacunación/veterinaria , Aborto Veterinario/parasitología , Animales , Bovinos , Enfermedades de los Bovinos/parasitología , Coccidiosis/parasitología , Coccidiosis/prevención & control , Femenino , Israel , Embarazo , Vacunas Atenuadas/uso terapéutico
9.
Am J Clin Pathol ; 113(2): 275-9, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10664630

RESUMEN

We compared the grading and staging of transurethral resection of the bladder (TURB) and cystectomy specimens for 105 patients who underwent radical cystectomy for urothelial carcinoma between 1980 and 1984. Of 105 patients, 96% underwent cystectomy within 100 days of TURB (median interval, 10 days). Grading was performed according to the 1998 World Health Organization/International Society of Urologic Pathology grading system and staging according to the 1997 TNM classification. Histologic grade was low-grade, 13; high-grade, 92 in TURB specimens; low-grade, 17; high-grade, 88 in cystectomy specimens. Pathologic stage was Ta, 15; T1, 55; and T2, 35 in TURB specimens; Ta, 5; T1, 19; T2, 19; T3, 46; and T4, 16 in cystectomy specimens. Histologic grade at TURB was associated with pathologic stage at cystectomy (P < .001). When all advanced-stage (muscle-invasive) carcinomas (pT2 or more) were considered together, 55 patients were understaged by TURB, 4 had higher stage in TURB than in cystectomy, and 46 were the same stage as by cystectomy. Forty-three of 55 patients with stage T1 carcinoma at TURB had advanced-stage carcinoma at cystectomy, including 34 who had extravesicular extension (pT3 or more). We found pathologic understanding by TURB occurs in a significant number of patients with bladder cancer; the newly proposed grading system predicted final pathologic stage.


Asunto(s)
Carcinoma de Células Transicionales/patología , Cistectomía , Estadificación de Neoplasias , Uretra , Neoplasias de la Vejiga Urinaria/patología , Neoplasias de la Vejiga Urinaria/cirugía , Adulto , Anciano , Carcinoma de Células Transicionales/cirugía , Femenino , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Músculos/patología , Invasividad Neoplásica
10.
Mol Biol (Mosk) ; 36(2): 252-60, 2002.
Artículo en Ruso | MEDLINE | ID: mdl-11969086

RESUMEN

Gene content proved to be less than expected in completely sequenced eukaryotic genomes. Moreover, gene number differs only three times between such distant organisms as human and Drosophila. Hence it is likely that the essential functional and structural differences between the two species mostly depend on the regulation of gene activity than on the set and quality of genes themselves. New data demonstrate that changes in chromatin structure play a greater role in the fine gene activity regulation than considered before. R.B. Khesin had foresaw many chromatin functions that only recently came to be recognized. Khesin was interested in genome inconstancy over his last years. A higher content of several important chromosomal proteins was recently revealed in chromatin of transposable genetic elements (TGE). The possible role of TGE in chromatin organization in the nucleus is considered.


Asunto(s)
Cromatina/química , Elementos Transponibles de ADN , Heterocromatina , Proteínas Nucleares/metabolismo , Animales , Cromatina/ultraestructura , Proteínas Cromosómicas no Histona/genética , Proteínas Cromosómicas no Histona/metabolismo , Metilasas de Modificación del ADN/genética , Metilasas de Modificación del ADN/metabolismo , Regulación de la Expresión Génica , Humanos , Proteínas Nucleares/genética
11.
Mol Biol (Mosk) ; 10(1): 3-34, 1976.
Artículo en Ruso | MEDLINE | ID: mdl-785238

RESUMEN

The problem to be reviewed in this study concerns the mechanism of regulation of gene activity relied on the structural changes of the chromatin. The role of histones in the regulation of transcription is discussed on the basis of the results obtained by the authors and literature data. In particular, the results are presented of the investigations of decrease of the histone amount in the cell nucleus using the deficiency of histone structural genes. This leads both to the increase of the X-chromosome template activity and the inhibition of variegated position effect. The latter is also inhibited by feeding of larvae with T2-DNA. It is supposed that the chromatin structure is a mechanism of epigenetic changes and the gene inactivation due to the position effect inherited in cell lineages in an example of such epigenetic changes.


Asunto(s)
Drosophila/fisiología , Animales , Catálisis , Cromosomas/ultraestructura , ARN Polimerasas Dirigidas por ADN , Escherichia coli/enzimología , Femenino , Genes , Histonas/biosíntesis , Masculino , ARN/biosíntesis , Cromosomas Sexuales , Transcripción Genética
12.
Mol Biol (Mosk) ; 15(2): 387-93, 1981.
Artículo en Ruso | MEDLINE | ID: mdl-6787408

RESUMEN

The amount of histone structural genes was determined in heterozygotes for two different deficiencies of the histone locus of the 2nd chromosome. In case one chromosome lacks histone genes, the number of histone structural genes in the normal homologous chromosome is likely to increase by means of magnification and compensation in the same way as in the case of rRNA genes.


Asunto(s)
Genes , Histonas/genética , Animales , Cromosomas/fisiología , Drosophila melanogaster/genética , Heterocigoto , Histonas/deficiencia
13.
Genetika ; 26(5): 817-25, 1990 May.
Artículo en Ruso | MEDLINE | ID: mdl-2168853

RESUMEN

The distribution along Drosophila melanogaster polytene X-chromosome and autosomes of 10911 in situ hybridization sites of a broad spectrum of copialike mobile elements is investigated. It is shown that against DNA content X-chromsomal cytological sections 14 + 15 and 16 + 17 contain much less mobile elements than other chromosomal regions. These X-chromosomal regions are also characterized both by significant decrease in the meiotic recombination frequencies and the amount of poly(dC-dA).poly(dG-dT) sequences which are capable to generate the Z form of DNA.


Asunto(s)
Cromosomas , Elementos Transponibles de ADN , Drosophila melanogaster/genética , Cromosoma X , Animales , Mapeo Cromosómico , Marcadores Genéticos
14.
Genetika ; 26(2): 241-8, 1990 Feb.
Artículo en Ruso | MEDLINE | ID: mdl-2160902

RESUMEN

The distribution of four genome DNA fragments containing different mobile elements in chromosomes of Drosophila melanogaster individuals from Azerbaijan coast and mountain populations was studied. The average copy number of each element was shown to be approx. equal in both populations. Sites of preferential localization, where the elements were present in no less than in half of individuals could be revealed in each population for all the elements. A part of these sites coincided with regions of intercalary heterochromatin, the number of such coincidences being larger in mountain populations. The copy number of the mobile elements under study in X-chromosomes of individuals from natural populations as well as from laboratory strains was less than in autosomes. X-chromosomes of different individuals differed in mobile elements' localization more than autosomes. It was assumed that peculiarities of mobile elements' distribution in X-chromosome could reflect the effect of decondensed structure of chromatin in male X-chromosome on the transposition of mobile elements.


Asunto(s)
Elementos Transponibles de ADN , Drosophila melanogaster/genética , Animales , Azerbaiyán
15.
Genetika ; 27(8): 1316-23, 1991 Aug.
Artículo en Ruso | MEDLINE | ID: mdl-1761208

RESUMEN

A partial genomic library from the Batumi L stock of Drosophila melanogaster was constructed using yeast artificial chromosomes as vectors. The DNA was restricted by Not1 and large fragments were inserted into the YAC5 vector. The size of cloned DNA varied from 90 to 500 kb. 48 random clones were characterized by in situ hybridization to the Batumi L polytene salivary gland chromosome. Single euchromatic sites of hybridization were detected for 27 clones; 11 clones revealed the main euchromatic hybridization site and several additional sites scattered along the chromosomes; 8 clones carried repeats which hybridized to chromocenter and other chromosomal sites; clones with 500 and 90 kb inserts originated from the Y chromosomes and nucleolus, respectively. The library is enriched by the repeated sequences related to the b-heterochromatin.


Asunto(s)
Cromosomas Fúngicos , ADN/genética , Drosophila melanogaster/genética , Genoma , Saccharomyces cerevisiae/genética , Animales , Clonación Molecular , Vectores Genéticos/genética , Hibridación de Ácido Nucleico , Secuencias Repetitivas de Ácidos Nucleicos/genética , Glándulas Salivales/fisiología
16.
Genetika ; 28(4): 85-97, 1992 Apr.
Artículo en Ruso | MEDLINE | ID: mdl-1322343

RESUMEN

The distribution of four retrotransposon families (MDG1, MDG3, MDG4 and copia) on polytene chromosomes of different (from 9 to 15) Drosophila simulans strains is studied. The mean number of MDG1 and copia euchromatic hybridization sites (3 sites for each element) is drastically decreased in D. simulans in comparison with D. melanogaster (24 and 18 sites respectively). The mean number of MDG3 sites of hybridization is 5 in D. simulans against 12 in D. melanogaster. As for MDG4 both species have on the average about 2-3 euchromatic sites. The majority of MDG1 and copia and about a half of MDG3 euchromatic copies are localized in restricted number of sites (hot spots) on D. simulans polytene chromosomes. In D. melanogaster these elements are scattered along the chromosomes though there are some hot spots too. It appears that euchromatic copies of MDG1 and copia are considerably less mobile in D. simulans in contrast to D. melanogaster. Some common hot spots of retrotransposon localization in D. simulans and D. melanogaster were earlier described as intercalary heterochromatin regions in D. melanogaster. The level of interstrain variability of MDG4 hybridization sites is comparable in both species. Comparative blot-analysis of adult and larval salivary gland DNA shows that MDG1 and copia are situated mainly in euchromatic regions of D. melanogaster chromosomes. In D. simulans genome they are located mainly in heterochromatic regions underreplicated in salivary gland polytene chromosomes. There are interspecies differences in the distribution of retrotransposons in beta-heterochromatic chromosome regions.


Asunto(s)
Elementos Transponibles de ADN , Drosophila melanogaster/genética , Drosophila/genética , Animales , Southern Blotting , Cromosomas , ADN/análisis , Heterocromatina , Hibridación de Ácido Nucleico , Mapeo Restrictivo , Especificidad de la Especie
17.
Genetika ; 26(3): 474-84, 1990 Mar.
Artículo en Ruso | MEDLINE | ID: mdl-2113022

RESUMEN

The previously cloned Drosophila genome fragment Dm665 (2.4 kb) hybridizing with telomers on polytene chromosomes is a representative of the family of repeats, a part of which being organized in tandem clusters. The repeats are not transcribed in cell culture, are species-specific and represented in 200-250 copies per haploid genome. In natural and laboratory Drosophila lines polymorphism has been revealed with regard to homology with Dm665 in the telomeres.


Asunto(s)
Cromosomas/ultraestructura , Drosophila melanogaster/genética , Polimorfismo Genético , Secuencias Repetitivas de Ácidos Nucleicos , Animales , Cariotipificación , Homología de Secuencia de Ácido Nucleico
18.
Genetika ; 26(10): 1701-12, 1990 Oct.
Artículo en Ruso | MEDLINE | ID: mdl-2178142

RESUMEN

A mobile element (ME) having 91% homology with Dm1360 (Kholodilov et al., 1987) has been cloned from the Drosophila melanogaster genome and sequenced. The family of ME was designated hoppel. The members of this family are flanked by short inverted repeats likewise P, hobo and HB. The hoppel is hybridized with 10-30 euchromatic sites of polytene chromosomes of different Drosophila stocks. Abundant hybridization with heterochromatic regions of chromosomes-chromocenter, pericentric heterochromatin, the 4 chromosome and telomeres was observed in all stocks of D. melanogaster examined and in D. simulans. At least six genomic variants of ME differing in length of the central part were revealed. Hoppel possesses ARS activity similar to the P element. Two ME hoppel were shown to be arranged as a direct repeat in the recombinant phage.


Asunto(s)
Elementos Transponibles de ADN/genética , Drosophila melanogaster/genética , Heterocromatina , Secuencias Repetitivas de Ácidos Nucleicos , Animales , Southern Blotting , Cromosomas/ultraestructura , ADN/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Polimorfismo Genético , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico
19.
Ontogenez ; 5(6): 544-56, 1974.
Artículo en Ruso | MEDLINE | ID: mdl-4219955

RESUMEN

The incorporation of 3H-uridine in different regions of polytene chromosomes in live cells of the Drosophila melanogaster salivary glands was compared with the incorporation of 3H-UTP in the same regions under the incubation of cytological preparations of these chromosomes with the E. coli RNA polymerase. The label distribution by regions was compared with the DNA content in them. Individual regions of chromosomes differ by 3H-uridine incorporation in live cells to a much greater extent than by 3H-UTP incorporation in vitro under the incubation with a non-homologous enzyme. RNA synthesis in an exogenous enzyme depends on the DNA content in different chromosome regions to a much greater extent than RNA synthesis in vivo. The correlation of label distribution after 3H-uridine incorporation in live cells and after RNA synthesis in vitro on the preparations by the bacterial RNA polymerase is, correspondingly, very low. This enzyme forms, however, RNA's on puffs 2-3 times more actively than on the same regions in non-puffing state but this difference is dozens of times greater in live cells. RNA synthesis in vitro is, thus, non-specific and does not correspond practically to the intensity of RNA synthesis on the same chromosome regions in live cells. At the same time, as in live cells, the E. coli enzyme synthesizes twice more RNA on the single X-chromosome of males (1X2A) than on each of X-chromosomes of diploid (2X2A) and triploid (3X3A) females or superfemales (3X2A), whereas in intersexes (2X3A) X-chromosomes display intermediate template activity. Thus, RNA synthesis by a heterologous enzyme in vitro does not differ by this index from the synthesis in live cells. It is suggested that differences in the template activity of X-chromosomes in vitro depending on the sex index (X : A) are due to different degree of DNP condensation in these chromosomes. In spite of differences in the degree of condensation, the male X-chromosome binds on the fixed preparation approximately the same amount of thymus histone F1 carrying fluorochrome as each of two female X-chromosomes. Hence, there is no sharp difference between the male and female X-chromosomes by the number and length of DNA regions accessible for interaction with exogenous proteins. On the basis of the data obtained, a hypothesis about two levels and, respectively, two mechanisms of control gene activity in animal chromosomes is considered. The first mechanism is, supposedly, based on decondensation of DNP appears to result in that the same proteins-regulators in the same amount activate corresponding genes in X-chromosome in males twice more strongly than in females.


Asunto(s)
Cromosomas/metabolismo , ARN Polimerasas Dirigidas por ADN , ARN/biosíntesis , Transcripción Genética , Animales , Drosophila melanogaster , Escherichia coli/enzimología , Femenino , Histonas/metabolismo , Técnicas In Vitro , Masculino , Factores Sexuales
20.
Tsitol Genet ; 24(1): 23-8, 1990.
Artículo en Ruso | MEDLINE | ID: mdl-2140917

RESUMEN

Cloned Drosophila DNA fragments containing telomere-specific sequences have been hybridized in situ. It is found that intensity of their hybridization with telomeres greatly varies in different nuclei of the same salivary gland. This phenomenon is also observed for internal sites where some mobile elements included in several DNA fragments under investigation are located. Within each nucleus different regions are hybridized non-uniformly as well. It is suggested that these phenomena can be explained by varying polytenization in telomeres and some internal chromosomal regions.


Asunto(s)
Cromosomas/ultraestructura , ADN/genética , Variación Genética/genética , Hibridación de Ácido Nucleico , Animales , Bacteriófago lambda/genética , Clonación Molecular , Sondas de ADN , Drosophila melanogaster , Plásmidos/genética , Recombinación Genética
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