• meiosis
  • First, we have made much progress in recent years in elucidating the kinds of cellular components that are important for preventing errors in meiosis (the cell division process that produces gametes). (omrf.org)
  • A second project in our laboratory explores the basis of chromosome segregation errors in meiosis. (omrf.org)
  • We have developed a yeast model system in which each yeast cell has one pair of non-recombined partners in every meiosis. (omrf.org)
  • tumor
  • We are exploring details of its function in cancer cells as part of a collaboration with colleague Gary Gorbsky to better understand how it might be targeted to prevent tumor cell growth. (omrf.org)
  • These results suggest that a senescence gene or genes, which may be located on the Chinese hamster X chromosome, can be regulated by DNA methylation, and that escape from senescence and possibly loss of tumor suppressor gene activity can occur by epigenetic mechanisms. (sciencemag.org)
  • This suggests that chromosome instability and aneuploidy may play a critical role in tumor development and progression ( Sen, 2000 ). (biologists.org)
  • mechanism
  • The mechanism by which specific regions of the chromosome are organized and segregated prior to division remains a mystery. (wiley.com)
  • The selected Xi becomes the target of a chromosome‐wide mechanism of transcriptional silencing, which constitutes an exciting paradigm for epigenetic regulations and confirms interest in the molecular dissection of the X‐inactivation centre ( Xic ), a locus on the X chromosome that contains the Xist gene and the elements involved in counting, choice and silencing. (embopress.org)
  • occurs
  • The speed at which this occurs (reviewed in Gordon and Wright, 2000 ) rules out passive models for bacterial chromosome segregation, which proposed that outward cellular growth could drive the movement of a fixed chromosome. (wiley.com)
  • X chromosome inactivation (XCI), which occurs only in female (XX) and not in male (XY) embryos, ensures dosage compensation of X‐linked genes between the sexes. (embopress.org)
  • The random form of XCI occurs around the time of implantation of the late female blastocyst, in the differentiating epiblast that derives from the inner cell mass (ICM) and that will give rise to the embryo proper. (embopress.org)
  • 2001
  • In the 'extrusion-capture' model, replication through an anchored replisome provides the force to move daughter chromosomes to the poles ( Lemon and Grossman, 2001 ). (wiley.com)
  • Proper
  • Initiation of XCI in the embryo proper also includes the random choice of the active (Xa) and the inactive (Xi) Xs in each cell. (embopress.org)
  • rapidly
  • After replication at mid-cell, the origin region ( oriC ) is rapidly segregated outward. (wiley.com)
  • Genetic
  • This lack of detailed knowledge about sex chromosome evolution compromises our understanding of fundamental biological questions (e.g. the evolution of sexual conflicts) as well as more practical ones (e.g. about sex-linked genetic diseases). (lu.se)
  • cellular
  • This system has allowed us to describe the cellular processes that are used to correctly partition the error-prone chromosomes in most meioses. (omrf.org)
  • The integrity of the cell and of its genome and the correct accomplishment of cellular processes depend on the existence of control points in the cell cycle. (biologists.org)
  • discovery
  • Ever since their discovery, these chromosomes have captivated researchers because of their obvious involvement in fundamental aspects of an organism's life, such as sex determination, sexual reproduction and sexual conflicts. (lu.se)
  • events
  • We propose a model in which ObgE is required to license chromosome segregation and subsequent cell cycle events. (wiley.com)
  • These control mechanisms, called `checkpoints', inhibit the transition to the next cell cycle phase if the events of the previous phase have not been correctly executed. (biologists.org)
  • involvement
  • Furthermore, we show that the 65 kb deletion also leads to inappropriate XCI in XY differentiated ES cells, which excludes the involvement of sex‐specific mechanisms in the initiation of XCI. (embopress.org)
  • early
  • At early passages of the A9/CX donor cells, the hamster X chromosome was highly active, inducing senescence in 100% of the colonies obtained after its transfer into the nickel-transformed cells. (sciencemag.org)
  • content
  • Depletion of ObgE also results in cell filamentation, with polyploid DNA content. (wiley.com)
  • origin
  • Cells lacking ObgE continue to initiate replication, with a normal ratio of the origin to terminus. (wiley.com)
  • cause
  • Depletion of ObgE did not cause lethality, and cells recovered fully after expression of ObgE was restored. (wiley.com)
  • normal
  • Transfer of a normal Chinese hamster X chromosome (carried in a mouse A9 donor cell line) to a nickel-transformed Chinese hamster cell line with an Xq chromosome deletion resulted in senescense of these previously immortal cells. (sciencemag.org)
  • We show here that normal counting can be rescued in these deleted ES cells using cre/ lox P re‐insertion, and refine the location of elements controlling counting within a 20 kb bipartite domain. (embopress.org)