A REC8-dependent plant Shugoshin is required for maintenance of centromeric cohesion during meiosis and has no mitotic functions.
During meiosis, sequential release of sister chromatid cohesion (SSC) during two successive nuclear divisions allows the production of haploid gametes from diploid progenitor cells. Release of SSC along chromosome arms allows first a reductional segregation of homologs, and, subsequently, release of centromeric cohesion at anaphase II allows the segregation of chromatids. The Shugoshin (SGO) protein family plays a major role in the protection of centromeric cohesion in Drosophila and yeast. We have isolated a maize mutant that displays premature loss of centromeric cohesion at anaphase I. We showed that this phenotype is due to the absence of ZmSGO1 protein, a maize shugoshin homolog. We also show that ZmSGO1 is localized to the centromeres. The ZmSGO1 protein is not found on mitotic chromosomes and has no obvious mitotic function. On the basis of these results, we propose that ZmSGO1 specifically maintains centromeric cohesion during meiosis I and therefore suggest that SGO1 core functions during meiosis are conserved across kingdoms and in large-genome species. However, in contrast to other Shugoshins, we observed an early and REC8-dependent recruitment of ZmSGO1 in maize, suggesting that control of SGO1 recruitment to chromosomes is different in plants than in other model organisms.
Hamant
Olivier
O
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA.
Golubovskaya
Inna
I
Meeley
Robert
R
Fiume
Elisa
E
Timofejeva
Ljuda
L
Schleiffer
Alexander
A
Nasmyth
Kim
K
Cande
W Zacheus
WZ
D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002503:Centromere / Q000378:metabolism*; D002842:Chromatids / Q000378:metabolism*; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008540:Meiosis / Q000502:physiology*; D008856:Microscopy, Fluorescence; D009154:Mutation / Q000235:genetics; D010750:Phosphoproteins / Q000378:metabolism*; D003313:Zea mays / Q000378:metabolism* / Q000502:physiology
D018797:Cell Cycle Proteins; D010750:Phosphoproteins