• homologous
  • Second, the neo-sex chromosome is homologous to the sex chromosomes of mammals, which makes it possible - for the first time - to study mammalian X gene homologs in a novel, avian Z-linked environment where females are the heterogametic sex (ZW), and thus to draw direct parallels over the avian ZW-mammalian XY boundary. (lu.se)
  • chromosomal
  • Most likely this suppression was the result of a series of chromosomal inversions on the Y chromosome, which would also explain why the genes appear to be in order on the X but scrambled on the Y," Page explains. (abc.net.au)
  • tumor
  • 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)
  • human
  • The idea of morphological reduction of W is also enhanced by our perspective of the gradual shortening of human Y chromosome [ 5 ], although there are examples of Y becoming larger than X in non-human species [ 2 ]. (royalsocietypublishing.org)
  • The improper partitioning of chromosomes is responsible for a many human maladies. (omrf.org)
  • In addition, we have recently determined that the spindle checkpoint is especially important for the segregation of error-prone meiotic chromosomes and that the human spindle checkpoint protein, BubR1, can participate in this process in yeast. (omrf.org)
  • Nevertheless, many genes on the human Y chromosome have homologues (analogous genes) on the X chromosome. (abc.net.au)
  • The reconstruction of the defining events of human sex-chromosome evolution is analogous to the reconstruction of the evolution of species, except that we are looking at changes of a pair of chromosomes over geologic time rather than changes of whole organisms," says Lahn. (abc.net.au)
  • Biology
  • Our projects primarily use the yeast, Saccharomyces cerevisiae, as a model to elucidate conserved aspects of eukaryotic chromosome biology. (omrf.org)
  • 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)
  • cells
  • In a second project, we focus on what moves chromosomes when cells divide. (omrf.org)
  • 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)
  • 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)
  • However, senescence was reduced to 50% when Chinese hamster X chromosomes were transferred from later passage A9 cells. (sciencemag.org)
  • Full senescing activity of the intact hamster X chromosome was restored by treatment of the donor mouse cells with 5-azacytidine, which induced demethylation of DNA. (sciencemag.org)
  • cellular
  • 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)
  • 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)
  • 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)
  • The first events that created the sex chromosomes had been thought to have occurred at least 170 million years ago," says researcher Dr David Page. (abc.net.au)
  • By fossil digging on the sex chromosomes, we were able to reconstruct the four events that drove sex chromosomes into their distinctive X and Y forms, and to date when these events occurred during evolution," says Lahn. (abc.net.au)
  • found
  • The X chromosome was found to have four groups of genes physically arranged as four consecutive blocks, like the layers of rock in geological strata. (abc.net.au)
  • mechanism
  • The mechanism by which specific regions of the chromosome are organized and segregated prior to division remains a mystery. (wiley.com)
  • development
  • The findings suggest that the number of sex chromosomes influences the development of brain asymmetry not simply to modify the torque but in a complex pattern along the antero-posterior axis. (ox.ac.uk)
  • move
  • 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)
  • research
  • Research published in this week's Science reveals that the Y chromosome developed from an X-like ancestor around 300 million years ago. (abc.net.au)