condensin i reveals new insights on mouse meiotic chromosome structure and dynamicscondensin我揭示了新见解鼠标减数分裂染色体的结构和动力学.pdfVIP

Condensin I Reveals New Insights on Mouse Meiotic Chromosome Structure and Dynamics 1 ´ ´ 1 ´ 1 2 2 1 ´ 1 Alberto Viera *, Rocıo Gomez , Marıa T. Parra , John A. Schmiesing , Kyoko Yokomori , Julio S. Rufas , Jose A. Suja ´ ´ ´ 1 Departamento de Biologıa, Edificio de Biologicas, Universidad Autonoma de Madrid, Madrid, Spain, 2 Department of Biological Chemistry, College of Medicine, University of California at Irvine, Irvine, California, United States of America Chromosome shaping and individualization are necessary requisites to warrant the correct segregation of genomes in either mitotic or meiotic cell divisions. These processes are mainly prompted in vertebrates by three multiprotein complexes termed cohesin and condensin I and II. In the present study we have analyzed by immunostaining the appearance and subcellular distribution of condensin I in mouse mitotic and meiotic chromosomes. Our results demonstrate that in either mitotically or meiotically dividing cells, condensin I is loaded onto chromosomes by prometaphase. Condensin I is detectable as a fuzzy axial structure running inside chromatids of condensed chromosomes. The distribution of condensin I along the chromosome length is not uniform, since it preferentially accumulates close to the chromosome ends. Interestingly, these round accumulations found at the condensin I axes termini colocalized with telomere complexes. Additionally, we present the relative distribution of the condensin I and cohesin complexes in metaphase I bivalents. All these new data have allowed us to propose a comprehensive model for meiotic chromosome structure. ´ Citation: Viera A, Gomez R, Parra MT, Schmiesing JA, Yokomori K, et al (20