title: Trans-inactivation: Repression in a wrong place.
abstract: Trans-inactivation is the repression of genes on a normal chromosome under the influence of a rearranged homologous chromosome demonstrating the position effect variegation (PEV). This phenomenon was studied in detail on the example of brownDominantallele causing the repression of wild-type brown gene on the opposite chromosome. We have investigated another trans-inactivation-inducing chromosome rearrangement, In(2)A4 inversion. In both cases, brownDominantand In(2)A4, the repression seems to be the result of dragging of the euchromatic region of the normal chromosome into the heterochromatic environment. It was found that cis-inactivation (classical PEV) and trans-inactivation show different patterns of distribution along the chromosome and respond differently to PEV modifying genes. It appears that the causative mechanism of trans-inactivation is de novo heterochromatin assembly on euchromatic sequences dragged into the heterochromatic nuclear compartment. Trans-inactivation turns out to be the result of a combination of heterochromatin-induced position effect and the somatic interphase chromosome pairing that is widespread in Diptera.
authors.affiliation: a Department of Molecular Genetics of the Cell , Institute of Molecular Genetics, Russian Academy of Science , Moscow , Russia.
authors.forename: Aleksei S
authors.initials: AS
authors.lastname: Shatskikh
authors.affiliation: a Department of Molecular Genetics of the Cell , Institute of Molecular Genetics, Russian Academy of Science , Moscow , Russia.
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Abramov
authors.affiliation: a Department of Molecular Genetics of the Cell , Institute of Molecular Genetics, Russian Academy of Science , Moscow , Russia.
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Lavrov
mesh_terms: D000818:Animals; D055012:Chromosomal Position Effects; D004331:Drosophila melanogaster / Q000235:genetics*; D020868:Gene Silencing; D006570:Heterochromatin / Q000378:metabolism*
chemical_list: D006570:Heterochromatin
keywords: PEV; chromatin; heterochromatin; nuclear compartments; trans-inactivation; transcription