RESUMEN
The assembly of 20,000 sequencing reads obtained from shotgun and chromosome-specific libraries of the Spiroplasma citri genome yielded 77 chromosomal contigs totaling 1,674 kbp (92%) of the 1,820-kbp chromosome. The largest chromosomal contigs were positioned on the physical and genetic maps constructed from pulsed-field gel electrophoresis and Southern blot hybridizations. Thirty-eight contigs were annotated, resulting in 1,908 predicted coding sequences (CDS) representing an overall coding density of only 74%. Cellular processes, cell metabolism, and structural-element CDS account for 29% of the coding capacity, CDS of external origin such as viruses and mobile elements account for 24% of the coding capacity, and CDS of unknown function account for 47% of the coding capacity. Among these, 21% of the CDS group into 63 paralog families. The organization of these paralogs into conserved blocks suggests that they represent potential mobile units. Phage-related sequences were particularly abundant and include plectrovirus SpV1 and SVGII3 and lambda-like SpV2 sequences. Sixty-nine copies of transposases belonging to four insertion sequence (IS) families (IS30, IS481, IS3, and ISNCY) were detected. Similarity analyses showed that 21% of chromosomal CDS were truncated compared to their bacterial orthologs. Transmembrane domains, including signal peptides, were predicted for 599 CDS, of which 58 were putative lipoproteins. S. citri has a Sec-dependent protein export pathway. Eighty-four CDS were assigned to transport, such as phosphoenolpyruvate phosphotransferase systems (PTS), the ATP binding cassette (ABC), and other transporters. Besides glycolytic and ATP synthesis pathways, it is noteworthy that S. citri possesses a nearly complete pathway for the biosynthesis of a terpenoid.
Asunto(s)
Bacteriófagos/genética , Cromosomas Bacterianos/genética , Cromosomas Bacterianos/virología , Evolución Molecular , Recombinación Genética , Spiroplasma citri/genética , Spiroplasma citri/virología , Proteínas Bacterianas/genética , ADN Bacteriano/química , ADN Bacteriano/genética , Genoma Bacteriano , Secuencias Repetitivas Esparcidas , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Análisis de Secuencia de ADN , Eliminación de Secuencia , Transposasas/genéticaRESUMEN
The detection of t(14;18)(q32;q21) is advisable for the diagnosis of follicular lymphoma (FL). In 51 patients with FL, we evaluated the applicability and sensitivity of interphase fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) using commercially available reagents. In 23 patients, only a formalin-fixed lymph node was available. In 28 patients, both frozen and formalin-fixed lymph nodes were evaluated. Fluorescence in situ hybridization was found to be 100% applicable whatever the material type. With the use of IGH-BCL2 dual-fusion, dual-color probes, t(14;18) translocation was detected in 47 (92%) of 51 FL cases with concordant results between isolated nuclei (n = 41) and frozen cytologic imprints (n = 28). Twenty-two IGH-BCL2-positive cases were also studied on fixed sections with BCL2 split signal probes showing a BCL2 split in all. Conversely, no BCL2 split was observed in IGH-BCL2-negative cases (n = 4). Owing to DNA degradation as assessed by the failure of control genes amplification, the applicability of PCR was found to be 76% in fixed lymph nodes (n = 51). After exclusion of the 12 noninformative cases, the BIOMED-2 protocol allowed the detection of an IGH-BCL2 fusion in 25 (64%) of 39 fixed specimens with 11 PCR-negative (31%) of 36 FISH-positive cases. Even on frozen material with 100% applicability, the amplification of a BCL2-JH breakpoint was achieved in only 20 (71%) of 28 cases with 5 PCR-negative (20%) out of 25 FISH-positive cases. Therefore, FISH was found superior to PCR (using BIOMED-2 protocol) in detecting IGH-BCL2 fusion. Finally, FISH individualized 4 IGH-BCL2-negative FL cases without specific histopathologic features. With the use of split signal DNA probes, 1 case showed a trisomy of the BCL2 locus and another displayed BCL6 and IGH breakpoints that would suggest a t(3;14). Whether such IGH-BCL2-negative cases are characterized by alternative oncogenetic pathways remains to be determined.
Asunto(s)
Hibridación Fluorescente in Situ/métodos , Ganglios Linfáticos/patología , Linfoma Folicular/diagnóstico , Proteínas de Fusión Oncogénica/genética , Reacción en Cadena de la Polimerasa/métodos , Cromosomas Humanos Par 14 , Cromosomas Humanos Par 18 , Secciones por Congelación , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Interfase/genética , Ganglios Linfáticos/metabolismo , Linfoma Folicular/genética , Proteínas Proto-Oncogénicas c-bcl-2/genética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Fijación del Tejido , Translocación GenéticaRESUMEN
The relative levels of cyclin D1 (CCND1) (a) and (b) transcripts were determined by real-time reverse transcription polymerase chain reaction (RT-PCR) and found to vary according to the tissue origin in both control and tumor samples. A five-fold overexpression of both isoforms was observed in 28/38 cases of mantle cell lymphoma (MCL) and of only one isoform in 10/38 MCL. No correlation was observed between expression of cyclin D1 isoforms and CCND1 genotype at position 870.
Asunto(s)
Empalme Alternativo , Ciclina D1/biosíntesis , Ciclina D1/genética , Regulación Neoplásica de la Expresión Génica , Linfoma de Células del Manto/genética , Linfoma de Células del Manto/metabolismo , Polimorfismo Genético , Genotipo , Humanos , Leucocitos Mononucleares/metabolismo , Isoformas de Proteínas , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
The effects of mobile phone (GSM) microwaves on the ears of guinea pigs were investigated in two in vivo experiments and one in vitro experiment. In the first experiment, three groups of eight guinea pigs had their left ear exposed for 1 h/day, 5 days/week, for 2 months, to GSM microwaves (900 MHz. GSM modulated) at specific absorption rates (SARs) of 1, 2 and 4 W/kg respectively, and a fourth group was sham-exposed. Distortion-product otoacoustic emissions (DPOAEs) were measured for each ear before exposure, at the end of the 2-month exposure period, and 2 months later. In the second experiment, the same protocol was applied to eight sham-exposed and 16 exposed guinea pigs at 4W/kg, but the auditory brainstem response (ABR) thresholds were monitored. Repeated-measures ANOVA showed no difference in DPOAE amplitudes or in ABR thresholds between the exposed and non-exposed ears and between the sham-exposed and exposed groups In the course of the second experiment, acute effects were also investigated by measuring once, in all animals, ABR thresholds just before and just after the 1-h exposure: no statistically significant difference was observed. In vitro, the two organs of Corti (OCs) of newborn rats (n=15) were isolated and placed in culture. For each animal, one OC was exposed for 24-48 h to 1 W/kg GSM microwaves, and the other was sham-exposed. After 2-3 days of culture, all OCs were observed under light microscopy. They all appeared normal to naive observers at this stage of development. These results provided no evidence that microwave radiation, at the levels produced by mobile phones, caused damage to the inner ear or the auditory pathways in our experimental animals.
