Genetic Interactions Between mei-S332 and ord in the Control of Sister-Chromatid Cohesion

Corresponding author: Terry L. Orr-Weaver, Whitehead Institute, 9 Cambridge Center, Cambridge, MA 02142., weaver{at}wi.mit.edu (E-mail).

Communicating editor: R. S. HAWLEY

The Drosophila mei-S332 and ord gene products are essential for proper sister-chromatid cohesion during meiosis in both males and females. We have constructed flies that contain null mutations for both genes. Double-mutant flies are viable and fertile. Therefore, the lack of an essential role for either gene in mitotic cohesion cannot be explained by compensatory activity of the two proteins during mitotic divisions. Analysis of sex chromosome segregation in the double mutant indicates that ord is epistatic to mei-S332. We demonstrate that ord is not required for MEI-S332 protein to localize to meiotic centromeres. Although overexpression of either protein in a wild-type background does not interfere with normal meiotic chromosome segregation, extra ORD⁺ protein in mei-S332 mutant males enhances nondisjunction at meiosis II. Our results suggest that a balance between the activity of mei-S332 and ord is required for proper regulation of meiotic cohesion and demonstrate that additional proteins must be functioning to ensure mitotic sister-chromatid cohesion.

This article has been cited by other articles:

				M. A. Janicke, L. Lasko, R. Oldenbourg, and J. R. LaFountain Jr Chromosome Malorientations after Meiosis II Arrest Cause Nondisjunction Mol. Biol. Cell, May 1, 2007; 18(5): 1645 - 1656. [Abstract] [Full Text] [PDF]

				E. M. Balicky, M. W. Endres, C. Lai, and S. E. Bickel Meiotic Cohesion Requires Accumulation of ORD on Chromosomes before Condensation Mol. Biol. Cell, November 1, 2002; 13(11): 3890 - 3900. [Abstract] [Full Text] [PDF]

				L. V. Paliulis and R. B. Nicklas The Reduction of Chromosome Number in Meiosis Is Determined by Properties Built into the Chromosomes J. Cell Biol., September 18, 2000; 150(6): 1223 - 1232. [Abstract] [Full Text] [PDF]

				C. Rieder and R Cole Chromatid cohesion during mitosis: lessons from meiosis J. Cell Sci., January 8, 1999; 112(16): 2607 - 2613. [Abstract] [PDF]