Drosophila mars is required for organizing kinetochore microtubules during mitosis

Exp Cell Res. 2008 Oct 15;314(17):3209-20. doi: 10.1016/j.yexcr.2008.08.004. Epub 2008 Aug 19.

Abstract

Spindle assembly is essential for the equal distribution of genetic material to the daughter cells during mitosis. The process of spindle assembly is complicated and involves multiple levels of molecular regulation. It is generally accepted that mitotic spindles are emanated from the centrosomes and are assembled in the vicinity of chromosomes. However, the molecular mechanism involved in the spindle assembly during mitosis remains unclear. In this study, we have provided several lines of evidence to show that Drosophila Mars is required for the assembly and stabilization of kinetochore microtubules. In an immunocytochemical study, we show that Mars is mainly localized on the kinetochore microtubules during mitosis. Using RNA interference to deplete the Mars expression in Drosophila S2 cells resulted in the malformation of mitotic spindle that mainly lacked the kinetochore microtubules. The spindle defect resulted in mitotic delays by increasing the percentage of uncongressed chromosomes both in vitro and in vivo. In summary, this study has extended our previous study of Mars in cell cycle regulation and provided further evidence showing that Mars is required for the assembly of kinetochore microtubules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Centrosome / metabolism
  • Chromosomes / metabolism
  • Drosophila Proteins
  • Drosophila melanogaster / cytology
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / physiology*
  • Kinetochores / metabolism*
  • Kinetochores / ultrastructure
  • Larva / anatomy & histology
  • Larva / metabolism
  • Microtubules / metabolism*
  • Microtubules / ultrastructure
  • Mitosis / physiology*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • RNA Interference
  • RNA, Double-Stranded / metabolism
  • SAP90-PSD95 Associated Proteins
  • Spindle Apparatus / metabolism
  • Spindle Apparatus / ultrastructure
  • Tubulin / metabolism
  • ran GTP-Binding Protein / genetics
  • ran GTP-Binding Protein / metabolism

Substances

  • Drosophila Proteins
  • Mars protein, Drosophila
  • Nerve Tissue Proteins
  • RNA, Double-Stranded
  • SAP90-PSD95 Associated Proteins
  • Tubulin
  • ran GTP-Binding Protein