Transcription as source of genetic heterogeneity in budding yeast.

Transcription presents challenges to genome stability both directly, by altering genome topology and exposing single-stranded DNA to chemical insults and nucleases, and indirectly by introducing obstacles to the DNA replication machinery. Such obstacles include the RNA polymerase holoenzyme itself, DNA-bound regulatory factors, G-quadruplexes and RNA-DNA hybrid structures known as R-loops. Here, we review the detrimental impacts of transcription on genome stability in budding yeast, as well as the mitigating effects of transcription-coupled nucleotide excision repair and of systems that maintain DNA replication fork processivity and integrity.

Senescence in yeast is associated with amplified linear fragments of chromosome XII rather than ribosomal DNA circle accumulation.

The massive accumulation of extrachromosomal ribosomal DNA circles (ERCs) in yeast mother cells has been long cited as the primary driver of replicative ageing. ERCs arise through ribosomal DNA (rDNA) recombination, and a wealth of genetic data connects rDNA instability events giving rise to ERCs with shortened life span and other ageing pathologies. However, we understand little about the molecular effects of ERC accumulation.

Symptomatic abnormalities of dark adaptation in patients with EFEMP1 retinal dystrophy (Malattia Leventinese/Doyne honeycomb retinal dystrophy).

Purpose: To investigate the nature of symptomatic visual disturbance in patients with EFEMP1 retinal dystrophy in the absence of geographic atrophy or choroidal neovascularization.

Methods: Patients presenting to a tertiary referral centre underwent clinical evaluation, fluorescein angiography, colour contrast sensitivity, focal, pattern, and standard electroretinography, electrooculography, scotopic threshold perimetry and dark adaptometry.

Results: Clinical features included reduced central vision, difficulty passing from light to dark, and diffuse submacular and peripapillary deposits, which were hyperfluorescent by fluorescein angiography.

[Retinal vasculopathy associated with Berger's IgA nephropathy].

Aim: Ophthalmological complications associated with Berger's IgA nephropathy comprise scleritis, episcleritis, keratoconjunctivitis as well as anterior uveitis. We present a new association of IgA nephropathy with a retinal vasculopathy.

Methods: Presentation of two clinical cases.

Indocyanine green angiographic findings in choroidal hemangiomas: A study of 75 cases.

Indocyanine green (ICG) angiography is a new diagnostic modality that was suggested, in small series, to provide a typical angiographic pattern in cases of choroidal hemangioma. Our study, through an exceptionally large series of 75 patients, assessed in a prospective way whether a typical ICG pattern of choroidal hemangioma exists and what would be its possible variations. The most constant feature is the sequence of the different ICG angiographic phases.