title: Mitotic stability of small supernumerary marker chromosomes depends on their shape and telomeres - a long term in vitro study.
abstract: Mosaicism is present in more than 50% of the cases with small supernumerary marker chromosomes (sSMCs) and karyotype 47,XX,+mar/46,XX or 47,XY,+mar/46,XY. Recently we provided first evidence that the mitotic stability of sSMC is dependent on their structure, i.e. their shape. Thus, here we performed a long term in vitro study on 12 selected cell lines from the Else Kröner-Fresenius-sSMC-cellbank (http://ssmc-tl.com/ekf-cellbank.html) to test mitotic sSMC stability systematically. The obtained results showed that inverted duplicated shaped and also the so-called complex sSMCs (group 1) are by far more stable, than centric-minute- or ring-shaped sSMCs (groups 2). Generally speaking, the percentage of cells with group-1-sSMCs remained stable over 90 days of cell culture, while that of group-2-sSMCs in parts dramatically decreased. In one group-2-cell line the sSMC was even lost completely after 30 days of in vitro culture, in others the sSMC was depleted in up to 40% of the cells. Still the highest rate of sSMC loss was recorded during EBV-transformation. Overall, the major difference between groups 1 and 2 was the number of telomeres per sSMC. In group 1 the sSMCs had "original" telomeres at both of their ends; in group 2 the sSMCs had either no, possibly secondary acquired and/or only one original telomere. This absence of protective telomeric sequences in group 2 seems to make sSMC more susceptible for loss during cell division. Still, also a growth advantage of cells without sSMC cannot be neglected entirely.
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany.
authors.forename: Shaymaa Subhi
authors.initials: SS
authors.lastname: Hussein
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Kreskowski
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Ziegler
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Klein
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany.
authors.forename: Ahmed B
authors.initials: AB
authors.lastname: Hamid
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany.
authors.forename: Nadezda
authors.initials: N
authors.lastname: Kosyakova
authors.affiliation: Institut für Humangenetik, Universitätsklinikum, Leipziger Str. 44, 39120 Magdeburg, Germany.
authors.forename: Marianne
authors.initials: M
authors.lastname: Volleth
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany. Electronic address: Thomas.Liehr@med.uni-jena.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Liehr
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Fan
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, D-07743 Jena, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Piaszinski
mesh_terms: D002460:Cell Line; D002869:Chromosome Aberrations; D002877:Chromosomes, Human; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008938:Mitosis; D009030:Mosaicism; D016615:Telomere
keywords: Cell lines; Marker chromosome shape; Small supernumerary marker chromosomes (sSMCs); Telomeres