Viruses and mammalian chromosomes chromosome aberrations by human adenovirus type 12

A Study of Meiosis in Virus Infected <i>Datura quarcifolia</i>

“…Diaz and Pavan (1965) reported anomalies like increased cell and chromosomes size associated with fragmentation of chromosomes i.e. characteristics of tumour formation in insect Phynchosciara angelae following protozoan and virus infection, while Stich et al (1964) and Hampar et al (1961) found similar effect in tissue culture strains infected with adenovirus type 12 and Harpes simplex virus. Along with the cytological effects, physiological disturbances too are very pronounced, rather, changes in cell physiology are the initial consequences of any infection.…”

The Transcriptionally Competent U2 Gene Is Necessary and Sufficient for Adenovirus Type 12 Induction of the Fragile Site at 17q21-22

“…Exceptions include the fragile site FRAXA, for which expansion and methylation of a trinucleotide repeat and delayed replication have been implicated in fragility of the FMR1 locus in individuals affected with fragile X syndrome (12). Recent data have shown that the same mechanism is responsible for fragility at three other sites: FRAXE, FRAXF, and FRA16A (15,24,27).Oncogenic adenoviruses, such as adenovirus type 12 (Ad12), are capable of inducing fragility at four chromosomal regions, referred to as Ad12 modification sites (8,23,30,33,39). This effect does not depend upon integration of the viral genome (8) but requires expression of viral proteins (30).…”

“…An additional shared feature of Ad12 modification sites is their proximity to or coincidence with gene clusters for structural RNAs: U2 small nuclear RNA at the 17q21-22 site and U1 genes or pseudogenes and 5S rRNA genes at 1p36, 1q21, and 1q42-43, respectively (11,19,20,25,32). Sensitivity to the virus varies among these sites, with the one at 17q21-22 being the most sensitive (8,23,30,33,39). We have exploited this viral system to investigate the mode of induction of chromosome fragility and to define the genomic sequences which are the target of this process.…”

“…Oncogenic adenoviruses, such as adenovirus type 12 (Ad12), are capable of inducing fragility at four chromosomal regions, referred to as Ad12 modification sites (8,23,30,33,39). This effect does not depend upon integration of the viral genome (8) but requires expression of viral proteins (30).…”

“…This effect does not depend upon integration of the viral genome (8) but requires expression of viral proteins (30). On the basis of their cytogenetic appearance (uncoiled chromatin and heterochromatic gaps) and their map location at or near sites frequently rearranged in human cancer, Ad12 modification sites are likely to represent true fragile sites (5,8,23,30,33,39). Indeed, Ad12 sites are also sensitive to drugs which induce common fragile sites (5,38).…”