title: MAOA and GYG2 are submitted to X chromosome inactivation in human fibroblasts.
abstract: X chromosome inactivation (XCI) is a comprehensively studied phenomenon that helped to highlight the heritable nature of epigenetic modifications. Although it consists of the transcriptional inactivation of a whole X chromosome in females, some genes escape this process and present bi-allelic expression. Using human fibroblasts with skewed inactivation, we determined allele-specific expression of two X-linked genes previously described to escape XCI in rodent/human somatic cell hybrids, MAOA and GYG2, and the pattern of DNA methylation of their 5' end. Results from these complementary methodologies let us to conclude that both genes are subjected to X inactivation in normal human fibroblasts, indicating that hybrid cells are not an adequate system for studying epigenotypes. We emphasize the need of an analysis of XCI in normal human cell lines, helping us to determine more precisely which X-linked genes contribute to differences among genders and to the phenotypes associated with sex chromosomes aneuploidies.
authors.affiliation: Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Raquel
authors.initials: R
authors.lastname: Stabellini
authors.forename: Luciana R
authors.initials: LR
authors.lastname: Vasques
authors.forename: Joana Carvalho Moreira
authors.initials: JC
authors.lastname: de Mello
authors.forename: Lys Molina
authors.initials: LM
authors.lastname: Hernandes
authors.forename: Lygia V
authors.initials: LV
authors.lastname: Pereira
mesh_terms: D002460:Cell Line; D018899:CpG Islands; D019175:DNA Methylation; D005260:Female; D005347:Fibroblasts; D005838:Genotype; D005964:Glucosyltransferases / Q000235:genetics*; D006801:Humans; D008995:Monoamine Oxidase / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D049951:X Chromosome Inactivation
chemical_list: D008995:Monoamine Oxidase; D005964:Glucosyltransferases; C109150:GYG2 protein, human