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SHUGOSHIN s and PATRONUS protect meiotic centromere cohesion in A rabidopsis thaliana
Author(s) -
Zamariola Linda,
Storme Nico,
Vannerum Katrijn,
Vandepoele Klaas,
Armstrong Susan J.,
Franklin F. Christopher H.,
Geelen Danny
Publication year - 2014
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12432
Subject(s) - cohesin , establishment of sister chromatid cohesion , sister chromatids , meiosis ii , homologous chromosome , biology , separase , meiosis , chromosome segregation , centromere , chromatid , genetics , anaphase , microbiology and biotechnology , chromosome , gene
Summary In meiosis, chromosome cohesion is maintained by the cohesin complex, which is released in a two‐step manner. At meiosis I, the meiosis‐specific cohesin subunit R ec8 is cleaved by the protease Separase along chromosome arms, allowing homologous chromosome segregation. Next, in meiosis II , cleavage of the remaining centromere cohesin results in separation of the sister chromatids. In eukaryotes, protection of centromeric cohesion in meiosis I is mediated by SHUGOSHIN s ( SGO s). The Arabidopsis genome contains two SGO homologs. Here we demonstrate that Atsgo1 mutants show a premature loss of cohesion of sister chromatid centromeres at anaphase I and that A t SGO 2 partially rescues this loss of cohesion. In addition to SGO s, we characterize PATRONUS which is specifically required for the maintenance of cohesion of sister chromatid centromeres in meiosis II . In contrast to the Atsgo1 Atsgo2 double mutant, patronus T ‐ DNA insertion mutants only display loss of sister chromatid cohesion after meiosis I , and additionally show disorganized spindles, resulting in defects in chromosome segregation in meiosis. This leads to reduced fertility and aneuploid offspring. Furthermore, we detect aneuploidy in sporophytic tissue, indicating a role for PATRONUS in chromosome segregation in somatic cells. Thus, ploidy stability is preserved in Arabidopsis by PATRONUS during both meiosis and mitosis.