ABSTRACT
La epigenética es el cambio en la expresión de genes sin alteraciones en la secuencia del ADN. Implica una serie de mecanismos tales como la metilación de citosinas del ADN, el empaquetamiento del ADN a través de las modificaciones postraduccionales de las histonas y los microARNs. Los factores que regulan estos mecanismos son muy diversos y van desde la dieta, medio ambiente, hábitos, estrés, comportamiento, conducta, etc. Rev Argent Endocrinol Metab 51:66-74, 2014 Los autores declaran no poseer conflictos de interés.
Epigenetics is defined as changes in gene expression that are not caused by changes in the DNA sequence. It involves a number of mechanisms such as: DNA methylation, DNA packaging through post-translational modifications of histones and microRNAs. The factors that regulate these mechanisms are very diverse, including diet, environment, habits, stress, behavior, etc. Rev Argent Endocrinol Metab 51:66-74, 2014 No financial conflicts of interest exist.
ABSTRACT
Bacteriophage MB78 is a virulent phage of Salmonella typhimurium. The viral DNA is 42 kb in size and seems to be circularly permuted. We show that viral DNA replication is through concatemeric DNA formation which is subsequently converted into full length DNA through headful packaging. A restriction map of MB78 DNA for six restriction endonucleases e.g. BgIII, PvuII, ECORI, ClaI, SalI and SmaI has been constructed. The yield of certain fragments in less than molar amount is explained in terms of permutation and the headful mechanism of packaging. The packaging site (pac site) has been suggested.