RESUMEN

HarryOW and Peeb are Mycobacterium smegmatis mc2 155 Siphoviridae temperate phages with 52,935 and 41,876 base pairs in genome length, respectively. HarryOW belongs to the A1 subcluster and Peeb to the G1 subcluster. They were isolated and annotated by students from the SUNY Old Westbury Science and Technology Entry Program.

RESUMEN

UVA-induced deleterious effect of thiopurine prodrugs including azathioprine, 6-mercaptopurine and 6-thioguanine (6-TG) increases the risk of cancer development due to the incorporation of 6-TG in patients' DNA. The catalytic mechanism by which thiobases act as a sustained oxidant producer has yet to be explored, especially through the Type I electron transfer pathway that produces superoxide radicals (O2˙-). Under Fenton-like conditions O2˙- radicals convert to extremely reactive hydroxyl radicals (˙OH), thus carrying even higher risk of biological damage than that induced by the well-studied type II reaction. By monitoring 6-TG/UVA-induced photochemistry in mass spectra and superoxide radicals (O2˙-) via nitro blue tetrazolium (NBT) reduction, this work provides two new findings: (1) in the presence of reduced glutathione (GSH), the production of O2˙-via the type I reaction is enhanced 10-fold. 6-TG thiyl radicals are identified as the primary intermediate formed in the reaction of 6-TG with O2˙-. The restoration of 6-TG and concurrent generation of O2˙- occur via a 3-step-cycle: 6-TG type I photosensitization, O2˙- oxidation and GSH reduction. (2) In the absence of GSH, 6-TG thiyl radicals undergo oxygen addition and sulfur dioxide removal to form carbon radicals (C6) which further convert to thioether by reacting with 6-TG molecules. These findings help explain not only thiol-regulation in a biological system but chemoprevention of cancer.

Asunto(s)

ADN/química , ADN/efectos de la radiación , Glutatión/química , Superóxidos/química , Tioguanina/química , Catálisis , Dimerización , Radicales Libres/química , Eliminación de Gen , Humanos , Radical Hidroxilo/química , Oxidación-Reducción , Oxígeno/química , Trastornos por Fotosensibilidad , Sulfuros/química , Rayos Ultravioleta

RESUMEN

Recurrent microdeletions and microduplications of a 600-kb genomic region of chromosome 16p11.2 have been implicated in childhood-onset developmental disorders. We report the association of 16p11.2 microduplications with schizophrenia in two large cohorts. The microduplication was detected in 12/1,906 (0.63%) cases and 1/3,971 (0.03%) controls (P = 1.2 x 10(-5), OR = 25.8) from the initial cohort, and in 9/2,645 (0.34%) cases and 1/2,420 (0.04%) controls (P = 0.022, OR = 8.3) of the replication cohort. The 16p11.2 microduplication was associated with a 14.5-fold increased risk of schizophrenia (95% CI (3.3, 62)) in the combined sample. A meta-analysis of datasets for multiple psychiatric disorders showed a significant association of the microduplication with schizophrenia (P = 4.8 x 10(-7)), bipolar disorder (P = 0.017) and autism (P = 1.9 x 10(-7)). In contrast, the reciprocal microdeletion was associated only with autism and developmental disorders (P = 2.3 x 10(-13)). Head circumference was larger in patients with the microdeletion than in patients with the microduplication (P = 0.0007).

Asunto(s)

Cromosomas Humanos Par 16 , Duplicación de Gen , Predisposición Genética a la Enfermedad , Esquizofrenia/genética , Humanos , Factores de Riesgo

RESUMEN

Schizophrenia is a devastating neurodevelopmental disorder whose genetic influences remain elusive. We hypothesize that individually rare structural variants contribute to the illness. Microdeletions and microduplications >100 kilobases were identified by microarray comparative genomic hybridization of genomic DNA from 150 individuals with schizophrenia and 268 ancestry-matched controls. All variants were validated by high-resolution platforms. Novel deletions and duplications of genes were present in 5% of controls versus 15% of cases and 20% of young-onset cases, both highly significant differences. The association was independently replicated in patients with childhood-onset schizophrenia as compared with their parents. Mutations in cases disrupted genes disproportionately from signaling networks controlling neurodevelopment, including neuregulin and glutamate pathways. These results suggest that multiple, individually rare mutations altering genes in neurodevelopmental pathways contribute to schizophrenia.

Asunto(s)

Encéfalo/crecimiento & desarrollo , Eliminación de Gen , Duplicación de Gen , Mutación , Esquizofrenia/genética , Adolescente , Adulto , Edad de Inicio , Secuencia de Aminoácidos , Encéfalo/citología , Encéfalo/metabolismo , Estudios de Casos y Controles , Niño , Receptores ErbB/química , Receptores ErbB/genética , Receptores ErbB/fisiología , Transportador 1 de Aminoácidos Excitadores/química , Transportador 1 de Aminoácidos Excitadores/genética , Transportador 1 de Aminoácidos Excitadores/fisiología , Femenino , Predisposición Genética a la Enfermedad , Genoma Humano , Humanos , Masculino , Datos de Secuencia Molecular , Neuronas/citología , Neuronas/fisiología , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo de Nucleótido Simple , Receptor ErbB-4 , Esquizofrenia/fisiopatología , Transducción de Señal