Form follows function in geminiviral minichromosome architecture

• Published in: Virus research Vol. 196; pp. 44 - 55
• Main Authors: Paprotka, Tobias, Deuschle, Kathrin, Pilartz, Marcel, Jeske, Holger
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 22.01.2015
• Subjects: Abutilon mosaic virus; African cassava mosaic virus; Base Sequence; Begomovirus; DNA, Circular - chemistry; DNA, Circular - genetics; DNA, Viral; Geminiviridae; Geminiviridae - genetics; Gene Order; Genome, Viral; Indian cassava mosaic virus; Lycopersicon esculentum; Molecular Sequence Data; Nicotiana - virology; Nicotiana benthamiana; Plant Diseases - virology; Plant Leaves - virology; Tomato yellow leaf curl Sardinia virus; Tomato yellow leaf curl Sardinia virus; African cassava mosaic virus; Geminiviridae; Indian cassava mosaic virus; Begomovirus; Abutilon mosaic virus
• ISSN: 0168-1702; 1872-7492
• DOI: 10.1016/j.virusres.2014.11.004

•Detailed analysis of topoisomers of cccDNA of four geminiviruses.•First quantitative description of geminiviral cccDNA intermediates.•Minichromosomes with twelve nucleosomes are prevalent.•More condensed minichromosomes appear sporadically during the course of infection.•DNA forms involved in transcription and replication are to be distinguished carefully. A comprehensive survey on the viral minichromosomes of the begomoviruses Abutilon mosaic virus, tomato yellow leaf curl Sardinia virus, African cassava mosaic virus, Indian cassava mosaic virus (family Geminiviridae) during the course of infections in Nicotiana benthamiana is summarized. Using optimized one-dimensional and two-dimensional gel systems combined with blot hybridization and a standardized evaluation, discrete and heterogeneous virus-specific signals with different DNA forms were compared to trace functions of viral multiplication with inactive/active replication and/or transcription. A quantitative approach to compare the distantly related viruses during the course of infection with the aim to generalize the conclusions for geminiviruses has been developed. Focussing on the distribution of topoisomers of viral supercoiled DNA, which reflect minichromosomal stages, predominant minichromosomes with 12 nucleosomes, less with 13 nucleosomes and no with 11 nucleosomes were found. These results indicate that chromatin with only one open gap to bind transcription factors is the favourite form. The dynamics during infections in dependence on the experimental conditions is discussed with reference to the design of experiments for resistance breeding and molecular analyses.